From a80ce2c566e545b121ac1199fac216600cf05bd5 Mon Sep 17 00:00:00 2001
From: Geoff Romer <gromer@google.com>
Date: Wed, 7 Jul 2021 11:32:33 -0700
Subject: [PATCH] Consistent naming for Expression and Value. (#621)

- `Kind` enumerator names always match the corresponding factory function, accessor, and type names (if any).
- All abbreviations in those names are expanded.
- Those names always have a suffix to disambiguate expressions from values.

`VarTV` is excluded from these changes because there's a pending PR to remove it.
---
 executable_semantics/ast/expression.cpp       | 182 ++++----
 executable_semantics/ast/expression.h         | 162 +++----
 .../interpreter/interpreter.cpp               | 419 +++++++++---------
 .../interpreter/typecheck.cpp                 | 302 ++++++-------
 executable_semantics/interpreter/value.cpp    | 295 ++++++------
 executable_semantics/interpreter/value.h      | 131 +++---
 .../syntax/paren_contents.cpp                 |   2 +-
 .../syntax/paren_contents_test.cpp            |  60 +--
 executable_semantics/syntax/parser.ypp        |  79 ++--
 9 files changed, 846 insertions(+), 786 deletions(-)

diff --git a/executable_semantics/ast/expression.cpp b/executable_semantics/ast/expression.cpp
index 5ae915240394..2f4f13fb977c 100644
--- a/executable_semantics/ast/expression.cpp
+++ b/executable_semantics/ast/expression.cpp
@@ -8,145 +8,158 @@
 
 namespace Carbon {
 
-auto Expression::GetVariable() const -> const Variable& {
-  return std::get<Variable>(value);
+auto Expression::GetIdentifierExpression() const
+    -> const IdentifierExpression& {
+  return std::get<IdentifierExpression>(value);
 }
 
-auto Expression::GetFieldAccess() const -> const FieldAccess& {
-  return std::get<FieldAccess>(value);
+auto Expression::GetFieldAccessExpression() const
+    -> const FieldAccessExpression& {
+  return std::get<FieldAccessExpression>(value);
 }
 
-auto Expression::GetIndex() const -> const Index& {
-  return std::get<Index>(value);
+auto Expression::GetIndexExpression() const -> const IndexExpression& {
+  return std::get<IndexExpression>(value);
 }
 
-auto Expression::GetPatternVariable() const -> const PatternVariable& {
-  return std::get<PatternVariable>(value);
+auto Expression::GetPatternVariableExpression() const
+    -> const PatternVariableExpression& {
+  return std::get<PatternVariableExpression>(value);
 }
 
-auto Expression::GetInteger() const -> int {
+auto Expression::GetIntLiteral() const -> int {
   return std::get<IntLiteral>(value).value;
 }
 
-auto Expression::GetBoolean() const -> bool {
+auto Expression::GetBoolLiteral() const -> bool {
   return std::get<BoolLiteral>(value).value;
 }
 
-auto Expression::GetTuple() const -> const Tuple& {
-  return std::get<Tuple>(value);
+auto Expression::GetTupleLiteral() const -> const TupleLiteral& {
+  return std::get<TupleLiteral>(value);
 }
 
-auto Expression::GetPrimitiveOperator() const -> const PrimitiveOperator& {
-  return std::get<PrimitiveOperator>(value);
+auto Expression::GetPrimitiveOperatorExpression() const
+    -> const PrimitiveOperatorExpression& {
+  return std::get<PrimitiveOperatorExpression>(value);
 }
 
-auto Expression::GetCall() const -> const Call& {
-  return std::get<Call>(value);
+auto Expression::GetCallExpression() const -> const CallExpression& {
+  return std::get<CallExpression>(value);
 }
 
-auto Expression::GetFunctionType() const -> const FunctionType& {
-  return std::get<FunctionType>(value);
+auto Expression::GetFunctionTypeLiteral() const -> const FunctionTypeLiteral& {
+  return std::get<FunctionTypeLiteral>(value);
 }
 
-auto Expression::MakeTypeType(int line_num) -> const Expression* {
+auto Expression::MakeTypeTypeLiteral(int line_num) -> const Expression* {
   auto* t = new Expression();
   t->line_num = line_num;
-  t->value = TypeT();
+  t->value = TypeTypeLiteral();
   return t;
 }
 
-auto Expression::MakeIntType(int line_num) -> const Expression* {
+auto Expression::MakeIntTypeLiteral(int line_num) -> const Expression* {
   auto* t = new Expression();
   t->line_num = line_num;
-  t->value = IntT();
+  t->value = IntTypeLiteral();
   return t;
 }
 
-auto Expression::MakeBoolType(int line_num) -> const Expression* {
+auto Expression::MakeBoolTypeLiteral(int line_num) -> const Expression* {
   auto* t = new Expression();
   t->line_num = line_num;
-  t->value = BoolT();
+  t->value = BoolTypeLiteral();
   return t;
 }
 
-auto Expression::MakeAutoType(int line_num) -> const Expression* {
+auto Expression::MakeAutoTypeLiteral(int line_num) -> const Expression* {
   auto* t = new Expression();
   t->line_num = line_num;
-  t->value = AutoT();
+  t->value = AutoTypeLiteral();
   return t;
 }
 
 // Returns a Continuation type AST node at the given source location.
-auto Expression::MakeContinuationType(int line_num) -> const Expression* {
+auto Expression::MakeContinuationTypeLiteral(int line_num)
+    -> const Expression* {
   auto* type = new Expression();
   type->line_num = line_num;
-  type->value = ContinuationT();
+  type->value = ContinuationTypeLiteral();
   return type;
 }
 
-auto Expression::MakeFunType(int line_num, const Expression* param,
-                             const Expression* ret) -> const Expression* {
+auto Expression::MakeFunctionTypeLiteral(int line_num, const Expression* param,
+                                         const Expression* ret)
+    -> const Expression* {
   auto* t = new Expression();
   t->line_num = line_num;
-  t->value = FunctionType({.parameter = param, .return_type = ret});
+  t->value = FunctionTypeLiteral({.parameter = param, .return_type = ret});
   return t;
 }
 
-auto Expression::MakeVar(int line_num, std::string var) -> const Expression* {
+auto Expression::MakeIdentifierExpression(int line_num, std::string var)
+    -> const Expression* {
   auto* v = new Expression();
   v->line_num = line_num;
-  v->value = Variable({.name = std::move(var)});
+  v->value = IdentifierExpression({.name = std::move(var)});
   return v;
 }
 
-auto Expression::MakeVarPat(int line_num, std::string var,
-                            const Expression* type) -> const Expression* {
+auto Expression::MakePatternVariableExpression(int line_num, std::string var,
+                                               const Expression* type)
+    -> const Expression* {
   auto* v = new Expression();
   v->line_num = line_num;
-  v->value = PatternVariable({.name = std::move(var), .type = type});
+  v->value = PatternVariableExpression({.name = std::move(var), .type = type});
   return v;
 }
 
-auto Expression::MakeInt(int line_num, int i) -> const Expression* {
+auto Expression::MakeIntLiteral(int line_num, int i) -> const Expression* {
   auto* e = new Expression();
   e->line_num = line_num;
   e->value = IntLiteral({.value = i});
   return e;
 }
 
-auto Expression::MakeBool(int line_num, bool b) -> const Expression* {
+auto Expression::MakeBoolLiteral(int line_num, bool b) -> const Expression* {
   auto* e = new Expression();
   e->line_num = line_num;
   e->value = BoolLiteral({.value = b});
   return e;
 }
 
-auto Expression::MakeOp(int line_num, enum Operator op,
-                        std::vector<const Expression*> args)
+auto Expression::MakePrimitiveOperatorExpression(
+    int line_num, enum Operator op, std::vector<const Expression*> args)
     -> const Expression* {
   auto* e = new Expression();
   e->line_num = line_num;
-  e->value = PrimitiveOperator({.op = op, .arguments = std::move(args)});
+  e->value =
+      PrimitiveOperatorExpression({.op = op, .arguments = std::move(args)});
   return e;
 }
 
-auto Expression::MakeCall(int line_num, const Expression* fun,
-                          const Expression* arg) -> const Expression* {
+auto Expression::MakeCallExpression(int line_num, const Expression* fun,
+                                    const Expression* arg)
+    -> const Expression* {
   auto* e = new Expression();
   e->line_num = line_num;
-  e->value = Call({.function = fun, .argument = arg});
+  e->value = CallExpression({.function = fun, .argument = arg});
   return e;
 }
 
-auto Expression::MakeGetField(int line_num, const Expression* exp,
-                              std::string field) -> const Expression* {
+auto Expression::MakeFieldAccessExpression(int line_num, const Expression* exp,
+                                           std::string field)
+    -> const Expression* {
   auto* e = new Expression();
   e->line_num = line_num;
-  e->value = FieldAccess({.aggregate = exp, .field = std::move(field)});
+  e->value =
+      FieldAccessExpression({.aggregate = exp, .field = std::move(field)});
   return e;
 }
 
-auto Expression::MakeTuple(int line_num, std::vector<FieldInitializer> args)
+auto Expression::MakeTupleLiteral(int line_num,
+                                  std::vector<FieldInitializer> args)
     -> const Expression* {
   auto* e = new Expression();
   e->line_num = line_num;
@@ -166,15 +179,15 @@ auto Expression::MakeTuple(int line_num, std::vector<FieldInitializer> args)
       seen_named_member = true;
     }
   }
-  e->value = Tuple({.fields = args});
+  e->value = TupleLiteral({.fields = args});
   return e;
 }
 
-auto Expression::MakeIndex(int line_num, const Expression* exp,
-                           const Expression* i) -> const Expression* {
+auto Expression::MakeIndexExpression(int line_num, const Expression* exp,
+                                     const Expression* i) -> const Expression* {
   auto* e = new Expression();
   e->line_num = line_num;
-  e->value = Index({.aggregate = exp, .offset = i});
+  e->value = IndexExpression({.aggregate = exp, .offset = i});
   return e;
 }
 
@@ -220,32 +233,32 @@ static void PrintFields(const std::vector<FieldInitializer>& fields) {
 
 void PrintExp(const Expression* e) {
   switch (e->tag()) {
-    case ExpressionKind::Index:
-      PrintExp(e->GetIndex().aggregate);
+    case ExpressionKind::IndexExpression:
+      PrintExp(e->GetIndexExpression().aggregate);
       std::cout << "[";
-      PrintExp(e->GetIndex().offset);
+      PrintExp(e->GetIndexExpression().offset);
       std::cout << "]";
       break;
-    case ExpressionKind::GetField:
-      PrintExp(e->GetFieldAccess().aggregate);
+    case ExpressionKind::FieldAccessExpression:
+      PrintExp(e->GetFieldAccessExpression().aggregate);
       std::cout << ".";
-      std::cout << e->GetFieldAccess().field;
+      std::cout << e->GetFieldAccessExpression().field;
       break;
-    case ExpressionKind::Tuple:
+    case ExpressionKind::TupleLiteral:
       std::cout << "(";
-      PrintFields(e->GetTuple().fields);
+      PrintFields(e->GetTupleLiteral().fields);
       std::cout << ")";
       break;
-    case ExpressionKind::Integer:
-      std::cout << e->GetInteger();
+    case ExpressionKind::IntLiteral:
+      std::cout << e->GetIntLiteral();
       break;
-    case ExpressionKind::Boolean:
+    case ExpressionKind::BoolLiteral:
       std::cout << std::boolalpha;
-      std::cout << e->GetBoolean();
+      std::cout << e->GetBoolLiteral();
       break;
-    case ExpressionKind::PrimitiveOp: {
+    case ExpressionKind::PrimitiveOperatorExpression: {
       std::cout << "(";
-      PrimitiveOperator op = e->GetPrimitiveOperator();
+      PrimitiveOperatorExpression op = e->GetPrimitiveOperatorExpression();
       if (op.arguments.size() == 0) {
         PrintOp(op.op);
       } else if (op.arguments.size() == 1) {
@@ -265,44 +278,45 @@ void PrintExp(const Expression* e) {
       std::cout << ")";
       break;
     }
-    case ExpressionKind::Variable:
-      std::cout << e->GetVariable().name;
+    case ExpressionKind::IdentifierExpression:
+      std::cout << e->GetIdentifierExpression().name;
       break;
-    case ExpressionKind::PatternVariable:
-      PrintExp(e->GetPatternVariable().type);
+    case ExpressionKind::PatternVariableExpression:
+      PrintExp(e->GetPatternVariableExpression().type);
       std::cout << ": ";
-      std::cout << e->GetPatternVariable().name;
+      std::cout << e->GetPatternVariableExpression().name;
       break;
-    case ExpressionKind::Call:
-      PrintExp(e->GetCall().function);
-      if (e->GetCall().argument->tag() == ExpressionKind::Tuple) {
-        PrintExp(e->GetCall().argument);
+    case ExpressionKind::CallExpression:
+      PrintExp(e->GetCallExpression().function);
+      if (e->GetCallExpression().argument->tag() ==
+          ExpressionKind::TupleLiteral) {
+        PrintExp(e->GetCallExpression().argument);
       } else {
         std::cout << "(";
-        PrintExp(e->GetCall().argument);
+        PrintExp(e->GetCallExpression().argument);
         std::cout << ")";
       }
       break;
-    case ExpressionKind::BoolT:
+    case ExpressionKind::BoolTypeLiteral:
       std::cout << "Bool";
       break;
-    case ExpressionKind::IntT:
+    case ExpressionKind::IntTypeLiteral:
       std::cout << "Int";
       break;
-    case ExpressionKind::TypeT:
+    case ExpressionKind::TypeTypeLiteral:
       std::cout << "Type";
       break;
-    case ExpressionKind::AutoT:
+    case ExpressionKind::AutoTypeLiteral:
       std::cout << "auto";
       break;
-    case ExpressionKind::ContinuationT:
+    case ExpressionKind::ContinuationTypeLiteral:
       std::cout << "Continuation";
       break;
-    case ExpressionKind::FunctionT:
+    case ExpressionKind::FunctionTypeLiteral:
       std::cout << "fn ";
-      PrintExp(e->GetFunctionType().parameter);
+      PrintExp(e->GetFunctionTypeLiteral().parameter);
       std::cout << " -> ";
-      PrintExp(e->GetFunctionType().return_type);
+      PrintExp(e->GetFunctionTypeLiteral().return_type);
       break;
   }
 }
diff --git a/executable_semantics/ast/expression.h b/executable_semantics/ast/expression.h
index dd0cb75d9926..6df5d6365022 100644
--- a/executable_semantics/ast/expression.h
+++ b/executable_semantics/ast/expression.h
@@ -23,21 +23,21 @@ struct FieldInitializer {
 };
 
 enum class ExpressionKind {
-  AutoT,
-  BoolT,
-  Boolean,
-  Call,
-  FunctionT,
-  GetField,
-  Index,
-  IntT,
-  ContinuationT,  // The type of a continuation value.
-  Integer,
-  PatternVariable,
-  PrimitiveOp,
-  Tuple,
-  TypeT,
-  Variable,
+  AutoTypeLiteral,
+  BoolTypeLiteral,
+  BoolLiteral,
+  CallExpression,
+  FunctionTypeLiteral,
+  FieldAccessExpression,
+  IndexExpression,
+  IntTypeLiteral,
+  ContinuationTypeLiteral,  // The type of a continuation value.
+  IntLiteral,
+  PatternVariableExpression,
+  PrimitiveOperatorExpression,
+  TupleLiteral,
+  TypeTypeLiteral,
+  IdentifierExpression,
 };
 
 enum class Operator {
@@ -55,124 +55,134 @@ enum class Operator {
 
 struct Expression;
 
-struct Variable {
-  static constexpr ExpressionKind Kind = ExpressionKind::Variable;
+struct IdentifierExpression {
+  static constexpr ExpressionKind Kind = ExpressionKind::IdentifierExpression;
   std::string name;
 };
 
-struct FieldAccess {
-  static constexpr ExpressionKind Kind = ExpressionKind::GetField;
+struct FieldAccessExpression {
+  static constexpr ExpressionKind Kind = ExpressionKind::FieldAccessExpression;
   const Expression* aggregate;
   std::string field;
 };
 
-struct Index {
-  static constexpr ExpressionKind Kind = ExpressionKind::Index;
+struct IndexExpression {
+  static constexpr ExpressionKind Kind = ExpressionKind::IndexExpression;
   const Expression* aggregate;
   const Expression* offset;
 };
 
-struct PatternVariable {
-  static constexpr ExpressionKind Kind = ExpressionKind::PatternVariable;
+struct PatternVariableExpression {
+  static constexpr ExpressionKind Kind =
+      ExpressionKind::PatternVariableExpression;
   std::string name;
   const Expression* type;
 };
 
 struct IntLiteral {
-  static constexpr ExpressionKind Kind = ExpressionKind::Integer;
+  static constexpr ExpressionKind Kind = ExpressionKind::IntLiteral;
   int value;
 };
 
 struct BoolLiteral {
-  static constexpr ExpressionKind Kind = ExpressionKind::Boolean;
+  static constexpr ExpressionKind Kind = ExpressionKind::BoolLiteral;
   bool value;
 };
 
-struct Tuple {
-  static constexpr ExpressionKind Kind = ExpressionKind::Tuple;
+struct TupleLiteral {
+  static constexpr ExpressionKind Kind = ExpressionKind::TupleLiteral;
   std::vector<FieldInitializer> fields;
 };
 
-struct PrimitiveOperator {
-  static constexpr ExpressionKind Kind = ExpressionKind::PrimitiveOp;
+struct PrimitiveOperatorExpression {
+  static constexpr ExpressionKind Kind =
+      ExpressionKind::PrimitiveOperatorExpression;
   Operator op;
   std::vector<const Expression*> arguments;
 };
 
-struct Call {
-  static constexpr ExpressionKind Kind = ExpressionKind::Call;
+struct CallExpression {
+  static constexpr ExpressionKind Kind = ExpressionKind::CallExpression;
   const Expression* function;
   const Expression* argument;
 };
 
-struct FunctionType {
-  static constexpr ExpressionKind Kind = ExpressionKind::FunctionT;
+struct FunctionTypeLiteral {
+  static constexpr ExpressionKind Kind = ExpressionKind::FunctionTypeLiteral;
   const Expression* parameter;
   const Expression* return_type;
 };
 
-struct AutoT {
-  static constexpr ExpressionKind Kind = ExpressionKind::AutoT;
+struct AutoTypeLiteral {
+  static constexpr ExpressionKind Kind = ExpressionKind::AutoTypeLiteral;
 };
 
-struct BoolT {
-  static constexpr ExpressionKind Kind = ExpressionKind::BoolT;
+struct BoolTypeLiteral {
+  static constexpr ExpressionKind Kind = ExpressionKind::BoolTypeLiteral;
 };
 
-struct IntT {
-  static constexpr ExpressionKind Kind = ExpressionKind::IntT;
+struct IntTypeLiteral {
+  static constexpr ExpressionKind Kind = ExpressionKind::IntTypeLiteral;
 };
 
-struct ContinuationT {
-  static constexpr ExpressionKind Kind = ExpressionKind::ContinuationT;
+struct ContinuationTypeLiteral {
+  static constexpr ExpressionKind Kind =
+      ExpressionKind::ContinuationTypeLiteral;
 };
 
-struct TypeT {
-  static constexpr ExpressionKind Kind = ExpressionKind::TypeT;
+struct TypeTypeLiteral {
+  static constexpr ExpressionKind Kind = ExpressionKind::TypeTypeLiteral;
 };
 
 struct Expression {
   int line_num;
   inline auto tag() const -> ExpressionKind;
 
-  static auto MakeVar(int line_num, std::string var) -> const Expression*;
-  static auto MakeVarPat(int line_num, std::string var, const Expression* type)
+  static auto MakeIdentifierExpression(int line_num, std::string var)
       -> const Expression*;
-  static auto MakeInt(int line_num, int i) -> const Expression*;
-  static auto MakeBool(int line_num, bool b) -> const Expression*;
-  static auto MakeOp(int line_num, Operator op,
-                     std::vector<const Expression*> args) -> const Expression*;
-  static auto MakeCall(int line_num, const Expression* fun,
-                       const Expression* arg) -> const Expression*;
-  static auto MakeGetField(int line_num, const Expression* exp,
-                           std::string field) -> const Expression*;
-  static auto MakeTuple(int line_num, std::vector<FieldInitializer> args)
+  static auto MakePatternVariableExpression(int line_num, std::string var,
+                                            const Expression* type)
       -> const Expression*;
-  static auto MakeIndex(int line_num, const Expression* exp,
-                        const Expression* i) -> const Expression*;
-  static auto MakeTypeType(int line_num) -> const Expression*;
-  static auto MakeIntType(int line_num) -> const Expression*;
-  static auto MakeBoolType(int line_num) -> const Expression*;
-  static auto MakeFunType(int line_num, const Expression* param,
-                          const Expression* ret) -> const Expression*;
-  static auto MakeAutoType(int line_num) -> const Expression*;
-  static auto MakeContinuationType(int line_num) -> const Expression*;
+  static auto MakeIntLiteral(int line_num, int i) -> const Expression*;
+  static auto MakeBoolLiteral(int line_num, bool b) -> const Expression*;
+  static auto MakePrimitiveOperatorExpression(
+      int line_num, Operator op, std::vector<const Expression*> args)
+      -> const Expression*;
+  static auto MakeCallExpression(int line_num, const Expression* fun,
+                                 const Expression* arg) -> const Expression*;
+  static auto MakeFieldAccessExpression(int line_num, const Expression* exp,
+                                        std::string field) -> const Expression*;
+  static auto MakeTupleLiteral(int line_num, std::vector<FieldInitializer> args)
+      -> const Expression*;
+  static auto MakeIndexExpression(int line_num, const Expression* exp,
+                                  const Expression* i) -> const Expression*;
+  static auto MakeTypeTypeLiteral(int line_num) -> const Expression*;
+  static auto MakeIntTypeLiteral(int line_num) -> const Expression*;
+  static auto MakeBoolTypeLiteral(int line_num) -> const Expression*;
+  static auto MakeFunctionTypeLiteral(int line_num, const Expression* param,
+                                      const Expression* ret)
+      -> const Expression*;
+  static auto MakeAutoTypeLiteral(int line_num) -> const Expression*;
+  static auto MakeContinuationTypeLiteral(int line_num) -> const Expression*;
 
-  auto GetVariable() const -> const Variable&;
-  auto GetFieldAccess() const -> const FieldAccess&;
-  auto GetIndex() const -> const Index&;
-  auto GetPatternVariable() const -> const PatternVariable&;
-  auto GetInteger() const -> int;
-  auto GetBoolean() const -> bool;
-  auto GetTuple() const -> const Tuple&;
-  auto GetPrimitiveOperator() const -> const PrimitiveOperator&;
-  auto GetCall() const -> const Call&;
-  auto GetFunctionType() const -> const FunctionType&;
+  auto GetIdentifierExpression() const -> const IdentifierExpression&;
+  auto GetFieldAccessExpression() const -> const FieldAccessExpression&;
+  auto GetIndexExpression() const -> const IndexExpression&;
+  auto GetPatternVariableExpression() const -> const PatternVariableExpression&;
+  auto GetIntLiteral() const -> int;
+  auto GetBoolLiteral() const -> bool;
+  auto GetTupleLiteral() const -> const TupleLiteral&;
+  auto GetPrimitiveOperatorExpression() const
+      -> const PrimitiveOperatorExpression&;
+  auto GetCallExpression() const -> const CallExpression&;
+  auto GetFunctionTypeLiteral() const -> const FunctionTypeLiteral&;
 
  private:
-  std::variant<Variable, FieldAccess, Index, PatternVariable, IntLiteral,
-               BoolLiteral, Tuple, PrimitiveOperator, Call, FunctionType, AutoT,
-               BoolT, IntT, ContinuationT, TypeT>
+  std::variant<IdentifierExpression, FieldAccessExpression, IndexExpression,
+               PatternVariableExpression, IntLiteral, BoolLiteral, TupleLiteral,
+               PrimitiveOperatorExpression, CallExpression, FunctionTypeLiteral,
+               AutoTypeLiteral, BoolTypeLiteral, IntTypeLiteral,
+               ContinuationTypeLiteral, TypeTypeLiteral>
       value;
 };
 
diff --git a/executable_semantics/interpreter/interpreter.cpp b/executable_semantics/interpreter/interpreter.cpp
index 64480bc8020a..5d1e1b207bfe 100644
--- a/executable_semantics/interpreter/interpreter.cpp
+++ b/executable_semantics/interpreter/interpreter.cpp
@@ -66,65 +66,66 @@ void Heap::CheckAlive(Address address, int line_num) {
 
 auto CopyVal(const Value* val, int line_num) -> const Value* {
   switch (val->tag) {
-    case ValKind::TupleV: {
+    case ValKind::TupleValue: {
       auto* elements = new std::vector<TupleElement>();
-      for (const TupleElement& element : *val->GetTuple().elements) {
+      for (const TupleElement& element : *val->GetTupleValue().elements) {
         const Value* new_element =
             CopyVal(state->heap.Read(element.address, line_num), line_num);
         Address new_address = state->heap.AllocateValue(new_element);
         elements->push_back({.name = element.name, .address = new_address});
       }
-      return Value::MakeTupleVal(elements);
+      return Value::MakeTupleValue(elements);
     }
-    case ValKind::AltV: {
+    case ValKind::AlternativeValue: {
       const Value* arg = CopyVal(
-          state->heap.Read(val->GetAlternative().argument, line_num), line_num);
+          state->heap.Read(val->GetAlternativeValue().argument, line_num),
+          line_num);
       Address argument_address = state->heap.AllocateValue(arg);
-      return Value::MakeAltVal(*val->GetAlternative().alt_name,
-                               *val->GetAlternative().choice_name,
-                               argument_address);
+      return Value::MakeAlternativeValue(
+          *val->GetAlternativeValue().alt_name,
+          *val->GetAlternativeValue().choice_name, argument_address);
     }
-    case ValKind::StructV: {
-      const Value* inits = CopyVal(val->GetStruct().inits, line_num);
-      return Value::MakeStructVal(val->GetStruct().type, inits);
+    case ValKind::StructValue: {
+      const Value* inits = CopyVal(val->GetStructValue().inits, line_num);
+      return Value::MakeStructValue(val->GetStructValue().type, inits);
     }
-    case ValKind::IntV:
-      return Value::MakeIntVal(val->GetInteger());
-    case ValKind::BoolV:
-      return Value::MakeBoolVal(val->GetBoolean());
-    case ValKind::FunV:
-      return Value::MakeFunVal(*val->GetFunction().name,
-                               val->GetFunction().param,
-                               val->GetFunction().body);
-    case ValKind::PtrV:
-      return Value::MakePtrVal(val->GetPointer());
-    case ValKind::ContinuationV:
+    case ValKind::IntValue:
+      return Value::MakeIntValue(val->GetIntValue());
+    case ValKind::BoolValue:
+      return Value::MakeBoolValue(val->GetBoolValue());
+    case ValKind::FunctionValue:
+      return Value::MakeFunctionValue(*val->GetFunctionValue().name,
+                                      val->GetFunctionValue().param,
+                                      val->GetFunctionValue().body);
+    case ValKind::PointerValue:
+      return Value::MakePointerValue(val->GetPointerValue());
+    case ValKind::ContinuationValue:
       // Copying a continuation is "shallow".
       return val;
-    case ValKind::FunctionTV:
-      return Value::MakeFunTypeVal(
+    case ValKind::FunctionType:
+      return Value::MakeFunctionType(
           CopyVal(val->GetFunctionType().param, line_num),
           CopyVal(val->GetFunctionType().ret, line_num));
 
-    case ValKind::PointerTV:
-      return Value::MakePtrTypeVal(
+    case ValKind::PointerType:
+      return Value::MakePointerType(
           CopyVal(val->GetPointerType().type, line_num));
-    case ValKind::IntTV:
-      return Value::MakeIntTypeVal();
-    case ValKind::BoolTV:
-      return Value::MakeBoolTypeVal();
-    case ValKind::TypeTV:
-      return Value::MakeTypeTypeVal();
+    case ValKind::IntType:
+      return Value::MakeIntType();
+    case ValKind::BoolType:
+      return Value::MakeBoolType();
+    case ValKind::TypeType:
+      return Value::MakeTypeType();
     case ValKind::VarTV:
       return Value::MakeVarTypeVal(*val->GetVariableType());
-    case ValKind::AutoTV:
-      return Value::MakeAutoTypeVal();
-    case ValKind::ContinuationTV:
-      return Value::MakeContinuationTypeVal();
-    case ValKind::StructTV:
-    case ValKind::ChoiceTV:
-    case ValKind::VarPatV:
-    case ValKind::AltConsV:
+    case ValKind::AutoType:
+      return Value::MakeAutoType();
+    case ValKind::ContinuationType:
+      return Value::MakeContinuationType();
+    case ValKind::StructType:
+    case ValKind::ChoiceType:
+    case ValKind::PatternVariableValue:
+    case ValKind::AlternativeConstructorValue:
       return val;  // no need to copy these because they are immutable?
       // No, they need to be copied so they don't get killed. -Jeremy
   }
@@ -132,14 +133,14 @@ auto CopyVal(const Value* val, int line_num) -> const Value* {
 
 void Heap::DeallocateSubObjects(const Value* val) {
   switch (val->tag) {
-    case ValKind::AltV:
-      Deallocate(val->GetAlternative().argument);
+    case ValKind::AlternativeValue:
+      Deallocate(val->GetAlternativeValue().argument);
       break;
-    case ValKind::StructV:
-      DeallocateSubObjects(val->GetStruct().inits);
+    case ValKind::StructValue:
+      DeallocateSubObjects(val->GetStructValue().inits);
       break;
-    case ValKind::TupleV:
-      for (const TupleElement& element : *val->GetTuple().elements) {
+    case ValKind::TupleValue:
+      for (const TupleElement& element : *val->GetTupleValue().elements) {
         Deallocate(element.address);
       }
       break;
@@ -226,8 +227,8 @@ void PrintState(std::ostream& out) {
 
 auto ValToInt(const Value* v, int line_num) -> int {
   switch (v->tag) {
-    case ValKind::IntV:
-      return v->GetInteger();
+    case ValKind::IntValue:
+      return v->GetIntValue();
     default:
       std::cerr << line_num << ": runtime error: expected an integer"
                 << std::endl;
@@ -237,8 +238,8 @@ auto ValToInt(const Value* v, int line_num) -> int {
 
 auto ValToBool(const Value* v, int line_num) -> int {
   switch (v->tag) {
-    case ValKind::BoolV:
-      return v->GetBoolean();
+    case ValKind::BoolValue:
+      return v->GetBoolValue();
     default:
       std::cerr << "runtime type error: expected a Boolean" << std::endl;
       exit(-1);
@@ -247,8 +248,8 @@ auto ValToBool(const Value* v, int line_num) -> int {
 
 auto ValToPtr(const Value* v, int line_num) -> Address {
   switch (v->tag) {
-    case ValKind::PtrV:
-      return v->GetPointer();
+    case ValKind::PointerValue:
+      return v->GetPointerValue();
     default:
       std::cerr << "runtime type error: expected a pointer, not ";
       PrintValue(v, std::cerr);
@@ -262,8 +263,8 @@ auto ValToPtr(const Value* v, int line_num) -> Address {
 // - Precondition: continuation->tag == ValKind::ContinuationV.
 auto ContinuationToVector(const Value* continuation, int sourceLocation)
     -> std::vector<Frame*> {
-  if (continuation->tag == ValKind::ContinuationV) {
-    return *continuation->GetContinuation().stack;
+  if (continuation->tag == ValKind::ContinuationValue) {
+    return *continuation->GetContinuationValue().stack;
   } else {
     std::cerr << sourceLocation << ": runtime error: expected an integer"
               << std::endl;
@@ -275,28 +276,28 @@ auto EvalPrim(Operator op, const std::vector<const Value*>& args, int line_num)
     -> const Value* {
   switch (op) {
     case Operator::Neg:
-      return Value::MakeIntVal(-ValToInt(args[0], line_num));
+      return Value::MakeIntValue(-ValToInt(args[0], line_num));
     case Operator::Add:
-      return Value::MakeIntVal(ValToInt(args[0], line_num) +
-                               ValToInt(args[1], line_num));
+      return Value::MakeIntValue(ValToInt(args[0], line_num) +
+                                 ValToInt(args[1], line_num));
     case Operator::Sub:
-      return Value::MakeIntVal(ValToInt(args[0], line_num) -
-                               ValToInt(args[1], line_num));
+      return Value::MakeIntValue(ValToInt(args[0], line_num) -
+                                 ValToInt(args[1], line_num));
     case Operator::Mul:
-      return Value::MakeIntVal(ValToInt(args[0], line_num) *
-                               ValToInt(args[1], line_num));
+      return Value::MakeIntValue(ValToInt(args[0], line_num) *
+                                 ValToInt(args[1], line_num));
     case Operator::Not:
-      return Value::MakeBoolVal(!ValToBool(args[0], line_num));
+      return Value::MakeBoolValue(!ValToBool(args[0], line_num));
     case Operator::And:
-      return Value::MakeBoolVal(ValToBool(args[0], line_num) &&
-                                ValToBool(args[1], line_num));
+      return Value::MakeBoolValue(ValToBool(args[0], line_num) &&
+                                  ValToBool(args[1], line_num));
     case Operator::Or:
-      return Value::MakeBoolVal(ValToBool(args[0], line_num) ||
-                                ValToBool(args[1], line_num));
+      return Value::MakeBoolValue(ValToBool(args[0], line_num) ||
+                                  ValToBool(args[1], line_num));
     case Operator::Eq:
-      return Value::MakeBoolVal(ValueEqual(args[0], args[1], line_num));
+      return Value::MakeBoolValue(ValueEqual(args[0], args[1], line_num));
     case Operator::Ptr:
-      return Value::MakePtrTypeVal(args[0]);
+      return Value::MakePointerType(args[0]);
     case Operator::Deref:
       std::cerr << line_num << ": dereference not implemented yet\n";
       exit(-1);
@@ -318,7 +319,7 @@ auto ChoiceDeclaration::InitGlobals(Env& globals) const -> void {
     auto t = InterpExp(Env(), signature);
     alts->push_back(make_pair(name, t));
   }
-  auto ct = Value::MakeChoiceTypeVal(name, alts);
+  auto ct = Value::MakeChoiceType(name, alts);
   auto a = state->heap.AllocateValue(ct);
   globals.Set(name, a);
 }
@@ -336,14 +337,14 @@ auto StructDeclaration::InitGlobals(Env& globals) const -> void {
       }
     }
   }
-  auto st = Value::MakeStructTypeVal(*definition.name, fields, methods);
+  auto st = Value::MakeStructType(*definition.name, fields, methods);
   auto a = state->heap.AllocateValue(st);
   globals.Set(*definition.name, a);
 }
 
 auto FunctionDeclaration::InitGlobals(Env& globals) const -> void {
   auto pt = InterpExp(globals, definition.param_pattern);
-  auto f = Value::MakeFunVal(definition.name, pt, definition.body);
+  auto f = Value::MakeFunctionValue(definition.name, pt, definition.body);
   Address a = state->heap.AllocateValue(f);
   globals.Set(definition.name, a);
 }
@@ -363,11 +364,11 @@ auto VariableDeclaration::InitGlobals(Env& globals) const -> void {
 void CallFunction(int line_num, std::vector<const Value*> operas,
                   State* state) {
   switch (operas[0]->tag) {
-    case ValKind::FunV: {
+    case ValKind::FunctionValue: {
       // Bind arguments to parameters
       std::list<std::string> params;
       std::optional<Env> matches =
-          PatternMatch(operas[0]->GetFunction().param, operas[1], globals,
+          PatternMatch(operas[0]->GetFunctionValue().param, operas[1], globals,
                        &params, line_num);
       if (!matches) {
         std::cerr << "internal error in call_function, pattern match failed"
@@ -377,24 +378,24 @@ void CallFunction(int line_num, std::vector<const Value*> operas,
       // Create the new frame and push it on the stack
       auto* scope = new Scope(*matches, params);
       auto* frame =
-          new Frame(*operas[0]->GetFunction().name, Stack(scope),
-                    Stack(MakeStmtAct(operas[0]->GetFunction().body)));
+          new Frame(*operas[0]->GetFunctionValue().name, Stack(scope),
+                    Stack(MakeStmtAct(operas[0]->GetFunctionValue().body)));
       state->stack.Push(frame);
       break;
     }
-    case ValKind::StructTV: {
+    case ValKind::StructType: {
       const Value* arg = CopyVal(operas[1], line_num);
-      const Value* sv = Value::MakeStructVal(operas[0], arg);
+      const Value* sv = Value::MakeStructValue(operas[0], arg);
       Frame* frame = state->stack.Top();
       frame->todo.Push(MakeValAct(sv));
       break;
     }
-    case ValKind::AltConsV: {
+    case ValKind::AlternativeConstructorValue: {
       const Value* arg = CopyVal(operas[1], line_num);
-      const Value* av =
-          Value::MakeAltVal(*operas[0]->GetAlternativeConstructor().alt_name,
-                            *operas[0]->GetAlternativeConstructor().choice_name,
-                            state->heap.AllocateValue(arg));
+      const Value* av = Value::MakeAlternativeValue(
+          *operas[0]->GetAlternativeConstructorValue().alt_name,
+          *operas[0]->GetAlternativeConstructorValue().choice_name,
+          state->heap.AllocateValue(arg));
       Frame* frame = state->stack.Top();
       frame->todo.Push(MakeValAct(av));
       break;
@@ -428,12 +429,12 @@ void CreateTuple(Frame* frame, Action* act, const Expression* /*exp*/) {
   //    { { (v1,...,vn) :: C, E, F} :: S, H}
   // -> { { `(v1,...,vn) :: C, E, F} :: S, H}
   auto elements = new std::vector<TupleElement>();
-  auto f = act->u.exp->GetTuple().fields.begin();
+  auto f = act->u.exp->GetTupleLiteral().fields.begin();
   for (auto i = act->results.begin(); i != act->results.end(); ++i, ++f) {
     Address a = state->heap.AllocateValue(*i);  // copy?
     elements->push_back({.name = f->name, .address = a});
   }
-  const Value* tv = Value::MakeTupleVal(elements);
+  const Value* tv = Value::MakeTupleValue(elements);
   frame->todo.Pop(1);
   frame->todo.Push(MakeValAct(tv));
 }
@@ -447,22 +448,22 @@ auto PatternMatch(const Value* p, const Value* v, Env values,
                   std::list<std::string>* vars, int line_num)
     -> std::optional<Env> {
   switch (p->tag) {
-    case ValKind::VarPatV: {
+    case ValKind::PatternVariableValue: {
       Address a = state->heap.AllocateValue(CopyVal(v, line_num));
-      vars->push_back(*p->GetVariablePattern().name);
-      values.Set(*p->GetVariablePattern().name, a);
+      vars->push_back(*p->GetPatternVariableValue().name);
+      values.Set(*p->GetPatternVariableValue().name, a);
       return values;
     }
-    case ValKind::TupleV:
+    case ValKind::TupleValue:
       switch (v->tag) {
-        case ValKind::TupleV: {
-          if (p->GetTuple().elements->size() !=
-              v->GetTuple().elements->size()) {
+        case ValKind::TupleValue: {
+          if (p->GetTupleValue().elements->size() !=
+              v->GetTupleValue().elements->size()) {
             std::cerr << "runtime error: arity mismatch in tuple pattern match"
                       << std::endl;
             exit(-1);
           }
-          for (const TupleElement& element : *p->GetTuple().elements) {
+          for (const TupleElement& element : *p->GetTupleValue().elements) {
             auto a = FindTupleField(element.name, v);
             if (a == std::nullopt) {
               std::cerr << "runtime error: field " << element.name << "not in ";
@@ -487,18 +488,19 @@ auto PatternMatch(const Value* p, const Value* v, Env values,
           std::cerr << std::endl;
           exit(-1);
       }
-    case ValKind::AltV:
+    case ValKind::AlternativeValue:
       switch (v->tag) {
-        case ValKind::AltV: {
-          if (*p->GetAlternative().choice_name !=
-                  *v->GetAlternative().choice_name ||
-              *p->GetAlternative().alt_name != *v->GetAlternative().alt_name) {
+        case ValKind::AlternativeValue: {
+          if (*p->GetAlternativeValue().choice_name !=
+                  *v->GetAlternativeValue().choice_name ||
+              *p->GetAlternativeValue().alt_name !=
+                  *v->GetAlternativeValue().alt_name) {
             return std::nullopt;
           }
           std::optional<Env> matches = PatternMatch(
-              state->heap.Read(p->GetAlternative().argument, line_num),
-              state->heap.Read(v->GetAlternative().argument, line_num), values,
-              vars, line_num);
+              state->heap.Read(p->GetAlternativeValue().argument, line_num),
+              state->heap.Read(v->GetAlternativeValue().argument, line_num),
+              values, vars, line_num);
           if (!matches) {
             return std::nullopt;
           }
@@ -512,9 +514,9 @@ auto PatternMatch(const Value* p, const Value* v, Env values,
           std::cerr << std::endl;
           exit(-1);
       }
-    case ValKind::FunctionTV:
+    case ValKind::FunctionType:
       switch (v->tag) {
-        case ValKind::FunctionTV: {
+        case ValKind::FunctionType: {
           std::optional<Env> matches =
               PatternMatch(p->GetFunctionType().param,
                            v->GetFunctionType().param, values, vars, line_num);
@@ -539,20 +541,20 @@ auto PatternMatch(const Value* p, const Value* v, Env values,
 
 void PatternAssignment(const Value* pat, const Value* val, int line_num) {
   switch (pat->tag) {
-    case ValKind::PtrV:
+    case ValKind::PointerValue:
       state->heap.Write(ValToPtr(pat, line_num), CopyVal(val, line_num),
                         line_num);
       break;
-    case ValKind::TupleV: {
+    case ValKind::TupleValue: {
       switch (val->tag) {
-        case ValKind::TupleV: {
-          if (pat->GetTuple().elements->size() !=
-              val->GetTuple().elements->size()) {
+        case ValKind::TupleValue: {
+          if (pat->GetTupleValue().elements->size() !=
+              val->GetTupleValue().elements->size()) {
             std::cerr << "runtime error: arity mismatch in tuple pattern match"
                       << std::endl;
             exit(-1);
           }
-          for (const TupleElement& element : *pat->GetTuple().elements) {
+          for (const TupleElement& element : *pat->GetTupleValue().elements) {
             auto a = FindTupleField(element.name, val);
             if (a == std::nullopt) {
               std::cerr << "runtime error: field " << element.name << "not in ";
@@ -575,19 +577,19 @@ void PatternAssignment(const Value* pat, const Value* val, int line_num) {
       }
       break;
     }
-    case ValKind::AltV: {
+    case ValKind::AlternativeValue: {
       switch (val->tag) {
-        case ValKind::AltV: {
-          if (*pat->GetAlternative().choice_name !=
-                  *val->GetAlternative().choice_name ||
-              *pat->GetAlternative().alt_name !=
-                  *val->GetAlternative().alt_name) {
+        case ValKind::AlternativeValue: {
+          if (*pat->GetAlternativeValue().choice_name !=
+                  *val->GetAlternativeValue().choice_name ||
+              *pat->GetAlternativeValue().alt_name !=
+                  *val->GetAlternativeValue().alt_name) {
             std::cerr << "internal error in pattern assignment" << std::endl;
             exit(-1);
           }
           PatternAssignment(
-              state->heap.Read(pat->GetAlternative().argument, line_num),
-              state->heap.Read(val->GetAlternative().argument, line_num),
+              state->heap.Read(pat->GetAlternativeValue().argument, line_num),
+              state->heap.Read(val->GetAlternativeValue().argument, line_num),
               line_num);
           break;
         }
@@ -621,46 +623,48 @@ void StepLvalue() {
     std::cout << " --->" << std::endl;
   }
   switch (exp->tag()) {
-    case ExpressionKind::Variable: {
+    case ExpressionKind::IdentifierExpression: {
       //    { {x :: C, E, F} :: S, H}
       // -> { {E(x) :: C, E, F} :: S, H}
       std::optional<Address> pointer =
-          CurrentEnv(state).Get(exp->GetVariable().name);
+          CurrentEnv(state).Get(exp->GetIdentifierExpression().name);
       if (!pointer) {
         std::cerr << exp->line_num << ": could not find `"
-                  << exp->GetVariable().name << "`" << std::endl;
+                  << exp->GetIdentifierExpression().name << "`" << std::endl;
         exit(-1);
       }
-      const Value* v = Value::MakePtrVal(*pointer);
+      const Value* v = Value::MakePointerValue(*pointer);
       frame->todo.Pop();
       frame->todo.Push(MakeValAct(v));
       break;
     }
-    case ExpressionKind::GetField: {
+    case ExpressionKind::FieldAccessExpression: {
       if (act->pos == 0) {
         //    { {e.f :: C, E, F} :: S, H}
         // -> { e :: [].f :: C, E, F} :: S, H}
-        frame->todo.Push(MakeLvalAct(exp->GetFieldAccess().aggregate));
+        frame->todo.Push(
+            MakeLvalAct(exp->GetFieldAccessExpression().aggregate));
         act->pos++;
       } else {
         //    { v :: [].f :: C, E, F} :: S, H}
         // -> { { &v.f :: C, E, F} :: S, H }
         const Value* str = act->results[0];
-        Address a = GetMember(ValToPtr(str, exp->line_num),
-                              exp->GetFieldAccess().field, exp->line_num);
+        Address a =
+            GetMember(ValToPtr(str, exp->line_num),
+                      exp->GetFieldAccessExpression().field, exp->line_num);
         frame->todo.Pop(1);
-        frame->todo.Push(MakeValAct(Value::MakePtrVal(a)));
+        frame->todo.Push(MakeValAct(Value::MakePointerValue(a)));
       }
       break;
     }
-    case ExpressionKind::Index: {
+    case ExpressionKind::IndexExpression: {
       if (act->pos == 0) {
         //    { {e[i] :: C, E, F} :: S, H}
         // -> { e :: [][i] :: C, E, F} :: S, H}
-        frame->todo.Push(MakeExpAct(exp->GetIndex().aggregate));
+        frame->todo.Push(MakeExpAct(exp->GetIndexExpression().aggregate));
         act->pos++;
       } else if (act->pos == 1) {
-        frame->todo.Push(MakeExpAct(exp->GetIndex().offset));
+        frame->todo.Push(MakeExpAct(exp->GetIndexExpression().offset));
         act->pos++;
       } else if (act->pos == 2) {
         //    { v :: [][i] :: C, E, F} :: S, H}
@@ -675,23 +679,25 @@ void StepLvalue() {
           exit(-1);
         }
         frame->todo.Pop(1);
-        frame->todo.Push(MakeValAct(Value::MakePtrVal(*a)));
+        frame->todo.Push(MakeValAct(Value::MakePointerValue(*a)));
       }
       break;
     }
-    case ExpressionKind::Tuple: {
+    case ExpressionKind::TupleLiteral: {
       if (act->pos == 0) {
         //    { {(f1=e1,...) :: C, E, F} :: S, H}
         // -> { {e1 :: (f1=[],...) :: C, E, F} :: S, H}
-        const Expression* e1 = exp->GetTuple().fields[0].expression;
+        const Expression* e1 = exp->GetTupleLiteral().fields[0].expression;
         frame->todo.Push(MakeLvalAct(e1));
         act->pos++;
-      } else if (act->pos != static_cast<int>(exp->GetTuple().fields.size())) {
+      } else if (act->pos !=
+                 static_cast<int>(exp->GetTupleLiteral().fields.size())) {
         //    { { vk :: (f1=v1,..., fk=[],fk+1=ek+1,...) :: C, E, F} :: S,
         //    H}
         // -> { { ek+1 :: (f1=v1,..., fk=vk, fk+1=[],...) :: C, E, F} :: S,
         // H}
-        const Expression* elt = exp->GetTuple().fields[act->pos].expression;
+        const Expression* elt =
+            exp->GetTupleLiteral().fields[act->pos].expression;
         frame->todo.Push(MakeLvalAct(elt));
         act->pos++;
       } else {
@@ -699,17 +705,17 @@ void StepLvalue() {
       }
       break;
     }
-    case ExpressionKind::Integer:
-    case ExpressionKind::Boolean:
-    case ExpressionKind::Call:
-    case ExpressionKind::PrimitiveOp:
-    case ExpressionKind::IntT:
-    case ExpressionKind::BoolT:
-    case ExpressionKind::TypeT:
-    case ExpressionKind::FunctionT:
-    case ExpressionKind::AutoT:
-    case ExpressionKind::ContinuationT:
-    case ExpressionKind::PatternVariable: {
+    case ExpressionKind::IntLiteral:
+    case ExpressionKind::BoolLiteral:
+    case ExpressionKind::CallExpression:
+    case ExpressionKind::PrimitiveOperatorExpression:
+    case ExpressionKind::IntTypeLiteral:
+    case ExpressionKind::BoolTypeLiteral:
+    case ExpressionKind::TypeTypeLiteral:
+    case ExpressionKind::FunctionTypeLiteral:
+    case ExpressionKind::AutoTypeLiteral:
+    case ExpressionKind::ContinuationTypeLiteral:
+    case ExpressionKind::PatternVariableExpression: {
       frame->todo.Pop();
       frame->todo.Push(MakeExpToLvalAct());
       frame->todo.Push(MakeExpAct(exp));
@@ -729,31 +735,31 @@ void StepExp() {
     std::cout << " --->" << std::endl;
   }
   switch (exp->tag()) {
-    case ExpressionKind::PatternVariable: {
+    case ExpressionKind::PatternVariableExpression: {
       if (act->pos == 0) {
-        frame->todo.Push(MakeExpAct(exp->GetPatternVariable().type));
+        frame->todo.Push(MakeExpAct(exp->GetPatternVariableExpression().type));
         act->pos++;
       } else {
-        auto v = Value::MakeVarPatVal(exp->GetPatternVariable().name,
-                                      act->results[0]);
+        auto v = Value::MakePatternVariableValue(
+            exp->GetPatternVariableExpression().name, act->results[0]);
         frame->todo.Pop(1);
         frame->todo.Push(MakeValAct(v));
       }
       break;
     }
-    case ExpressionKind::Index: {
+    case ExpressionKind::IndexExpression: {
       if (act->pos == 0) {
         //    { { e[i] :: C, E, F} :: S, H}
         // -> { { e :: [][i] :: C, E, F} :: S, H}
-        frame->todo.Push(MakeExpAct(exp->GetIndex().aggregate));
+        frame->todo.Push(MakeExpAct(exp->GetIndexExpression().aggregate));
         act->pos++;
       } else if (act->pos == 1) {
-        frame->todo.Push(MakeExpAct(exp->GetIndex().offset));
+        frame->todo.Push(MakeExpAct(exp->GetIndexExpression().offset));
         act->pos++;
       } else if (act->pos == 2) {
         auto tuple = act->results[0];
         switch (tuple->tag) {
-          case ValKind::TupleV: {
+          case ValKind::TupleValue: {
             //    { { v :: [][i] :: C, E, F} :: S, H}
             // -> { { v_i :: C, E, F} : S, H}
             std::string f = std::to_string(ToInteger(act->results[1]));
@@ -779,23 +785,25 @@ void StepExp() {
       }
       break;
     }
-    case ExpressionKind::Tuple: {
+    case ExpressionKind::TupleLiteral: {
       if (act->pos == 0) {
-        if (exp->GetTuple().fields.size() > 0) {
+        if (exp->GetTupleLiteral().fields.size() > 0) {
           //    { {(f1=e1,...) :: C, E, F} :: S, H}
           // -> { {e1 :: (f1=[],...) :: C, E, F} :: S, H}
-          const Expression* e1 = exp->GetTuple().fields[0].expression;
+          const Expression* e1 = exp->GetTupleLiteral().fields[0].expression;
           frame->todo.Push(MakeExpAct(e1));
           act->pos++;
         } else {
           CreateTuple(frame, act, exp);
         }
-      } else if (act->pos != static_cast<int>(exp->GetTuple().fields.size())) {
+      } else if (act->pos !=
+                 static_cast<int>(exp->GetTupleLiteral().fields.size())) {
         //    { { vk :: (f1=v1,..., fk=[],fk+1=ek+1,...) :: C, E, F} :: S,
         //    H}
         // -> { { ek+1 :: (f1=v1,..., fk=vk, fk+1=[],...) :: C, E, F} :: S,
         // H}
-        const Expression* elt = exp->GetTuple().fields[act->pos].expression;
+        const Expression* elt =
+            exp->GetTupleLiteral().fields[act->pos].expression;
         frame->todo.Push(MakeExpAct(elt));
         act->pos++;
       } else {
@@ -803,31 +811,33 @@ void StepExp() {
       }
       break;
     }
-    case ExpressionKind::GetField: {
+    case ExpressionKind::FieldAccessExpression: {
       if (act->pos == 0) {
         //    { { e.f :: C, E, F} :: S, H}
         // -> { { e :: [].f :: C, E, F} :: S, H}
-        frame->todo.Push(MakeLvalAct(exp->GetFieldAccess().aggregate));
+        frame->todo.Push(
+            MakeLvalAct(exp->GetFieldAccessExpression().aggregate));
         act->pos++;
       } else {
         //    { { v :: [].f :: C, E, F} :: S, H}
         // -> { { v_f :: C, E, F} : S, H}
-        auto a = GetMember(ValToPtr(act->results[0], exp->line_num),
-                           exp->GetFieldAccess().field, exp->line_num);
+        auto a =
+            GetMember(ValToPtr(act->results[0], exp->line_num),
+                      exp->GetFieldAccessExpression().field, exp->line_num);
         const Value* element = state->heap.Read(a, exp->line_num);
         frame->todo.Pop(1);
         frame->todo.Push(MakeValAct(element));
       }
       break;
     }
-    case ExpressionKind::Variable: {
+    case ExpressionKind::IdentifierExpression: {
       CHECK(act->pos == 0);
       // { {x :: C, E, F} :: S, H} -> { {H(E(x)) :: C, E, F} :: S, H}
       std::optional<Address> pointer =
-          CurrentEnv(state).Get(exp->GetVariable().name);
+          CurrentEnv(state).Get(exp->GetIdentifierExpression().name);
       if (!pointer) {
         std::cerr << exp->line_num << ": could not find `"
-                  << exp->GetVariable().name << "`" << std::endl;
+                  << exp->GetIdentifierExpression().name << "`" << std::endl;
         exit(-1);
       }
       const Value* pointee = state->heap.Read(*pointer, exp->line_num);
@@ -835,45 +845,47 @@ void StepExp() {
       frame->todo.Push(MakeValAct(pointee));
       break;
     }
-    case ExpressionKind::Integer:
+    case ExpressionKind::IntLiteral:
       CHECK(act->pos == 0);
       // { {n :: C, E, F} :: S, H} -> { {n' :: C, E, F} :: S, H}
       frame->todo.Pop(1);
-      frame->todo.Push(MakeValAct(Value::MakeIntVal(exp->GetInteger())));
+      frame->todo.Push(MakeValAct(Value::MakeIntValue(exp->GetIntLiteral())));
       break;
-    case ExpressionKind::Boolean:
+    case ExpressionKind::BoolLiteral:
       CHECK(act->pos == 0);
       // { {n :: C, E, F} :: S, H} -> { {n' :: C, E, F} :: S, H}
       frame->todo.Pop(1);
-      frame->todo.Push(MakeValAct(Value::MakeBoolVal(exp->GetBoolean())));
+      frame->todo.Push(MakeValAct(Value::MakeBoolValue(exp->GetBoolLiteral())));
       break;
-    case ExpressionKind::PrimitiveOp:
+    case ExpressionKind::PrimitiveOperatorExpression:
       if (act->pos !=
-          static_cast<int>(exp->GetPrimitiveOperator().arguments.size())) {
+          static_cast<int>(
+              exp->GetPrimitiveOperatorExpression().arguments.size())) {
         //    { {v :: op(vs,[],e,es) :: C, E, F} :: S, H}
         // -> { {e :: op(vs,v,[],es) :: C, E, F} :: S, H}
-        const Expression* arg = exp->GetPrimitiveOperator().arguments[act->pos];
+        const Expression* arg =
+            exp->GetPrimitiveOperatorExpression().arguments[act->pos];
         frame->todo.Push(MakeExpAct(arg));
         act->pos++;
       } else {
         //    { {v :: op(vs,[]) :: C, E, F} :: S, H}
         // -> { {eval_prim(op, (vs,v)) :: C, E, F} :: S, H}
-        const Value* v = EvalPrim(exp->GetPrimitiveOperator().op, act->results,
-                                  exp->line_num);
+        const Value* v = EvalPrim(exp->GetPrimitiveOperatorExpression().op,
+                                  act->results, exp->line_num);
         frame->todo.Pop(1);
         frame->todo.Push(MakeValAct(v));
       }
       break;
-    case ExpressionKind::Call:
+    case ExpressionKind::CallExpression:
       if (act->pos == 0) {
         //    { {e1(e2) :: C, E, F} :: S, H}
         // -> { {e1 :: [](e2) :: C, E, F} :: S, H}
-        frame->todo.Push(MakeExpAct(exp->GetCall().function));
+        frame->todo.Push(MakeExpAct(exp->GetCallExpression().function));
         act->pos++;
       } else if (act->pos == 1) {
         //    { { v :: [](e) :: C, E, F} :: S, H}
         // -> { { e :: v([]) :: C, E, F} :: S, H}
-        frame->todo.Push(MakeExpAct(exp->GetCall().argument));
+        frame->todo.Push(MakeExpAct(exp->GetCallExpression().argument));
         act->pos++;
       } else if (act->pos == 2) {
         //    { { v2 :: v1([]) :: C, E, F} :: S, H}
@@ -885,56 +897,56 @@ void StepExp() {
         exit(-1);
       }
       break;
-    case ExpressionKind::IntT: {
+    case ExpressionKind::IntTypeLiteral: {
       CHECK(act->pos == 0);
-      const Value* v = Value::MakeIntTypeVal();
+      const Value* v = Value::MakeIntType();
       frame->todo.Pop(1);
       frame->todo.Push(MakeValAct(v));
       break;
     }
-    case ExpressionKind::BoolT: {
+    case ExpressionKind::BoolTypeLiteral: {
       CHECK(act->pos == 0);
-      const Value* v = Value::MakeBoolTypeVal();
+      const Value* v = Value::MakeBoolType();
       frame->todo.Pop(1);
       frame->todo.Push(MakeValAct(v));
       break;
     }
-    case ExpressionKind::AutoT: {
+    case ExpressionKind::AutoTypeLiteral: {
       CHECK(act->pos == 0);
-      const Value* v = Value::MakeAutoTypeVal();
+      const Value* v = Value::MakeAutoType();
       frame->todo.Pop(1);
       frame->todo.Push(MakeValAct(v));
       break;
     }
-    case ExpressionKind::TypeT: {
+    case ExpressionKind::TypeTypeLiteral: {
       CHECK(act->pos == 0);
-      const Value* v = Value::MakeTypeTypeVal();
+      const Value* v = Value::MakeTypeType();
       frame->todo.Pop(1);
       frame->todo.Push(MakeValAct(v));
       break;
     }
-    case ExpressionKind::FunctionT: {
+    case ExpressionKind::FunctionTypeLiteral: {
       if (act->pos == 0) {
-        frame->todo.Push(MakeExpAct(exp->GetFunctionType().parameter));
+        frame->todo.Push(MakeExpAct(exp->GetFunctionTypeLiteral().parameter));
         act->pos++;
       } else if (act->pos == 1) {
         //    { { pt :: fn [] -> e :: C, E, F} :: S, H}
         // -> { { e :: fn pt -> []) :: C, E, F} :: S, H}
-        frame->todo.Push(MakeExpAct(exp->GetFunctionType().return_type));
+        frame->todo.Push(MakeExpAct(exp->GetFunctionTypeLiteral().return_type));
         act->pos++;
       } else if (act->pos == 2) {
         //    { { rt :: fn pt -> [] :: C, E, F} :: S, H}
         // -> { fn pt -> rt :: {C, E, F} :: S, H}
         const Value* v =
-            Value::MakeFunTypeVal(act->results[0], act->results[1]);
+            Value::MakeFunctionType(act->results[0], act->results[1]);
         frame->todo.Pop(1);
         frame->todo.Push(MakeValAct(v));
       }
       break;
     }
-    case ExpressionKind::ContinuationT: {
+    case ExpressionKind::ContinuationTypeLiteral: {
       CHECK(act->pos == 0);
-      const Value* v = Value::MakeContinuationTypeVal();
+      const Value* v = Value::MakeContinuationType();
       frame->todo.Pop(1);
       frame->todo.Push(MakeValAct(v));
       break;
@@ -1223,11 +1235,11 @@ void StepStmt() {
       scopes.Push(scope);
       Stack<Action*> todo;
       todo.Push(MakeStmtAct(Statement::MakeReturn(
-          stmt->line_num, Expression::MakeTuple(stmt->line_num, {}))));
+          stmt->line_num, Expression::MakeTupleLiteral(stmt->line_num, {}))));
       todo.Push(MakeStmtAct(stmt->GetContinuation().body));
       Frame* continuation_frame = new Frame("__continuation", scopes, todo);
       Address continuation_address = state->heap.AllocateValue(
-          Value::MakeContinuation({continuation_frame}));
+          Value::MakeContinuationValue({continuation_frame}));
       // Store the continuation's address in the frame.
       continuation_frame->continuation = continuation_address;
       // Bind the continuation object to the continuation variable
@@ -1247,7 +1259,7 @@ void StepStmt() {
         // Push an expression statement action to ignore the result
         // value from the continuation.
         Action* ignore_result = MakeStmtAct(Statement::MakeExpStmt(
-            stmt->line_num, Expression::MakeTuple(stmt->line_num, {})));
+            stmt->line_num, Expression::MakeTupleLiteral(stmt->line_num, {})));
         ignore_result->pos = 0;
         frame->todo.Push(ignore_result);
         // Push the continuation onto the current stack.
@@ -1269,7 +1281,7 @@ void StepStmt() {
       } while (!paused.back()->IsContinuation());
       // Update the continuation with the paused stack.
       state->heap.Write(paused.back()->continuation,
-                        Value::MakeContinuation(paused), stmt->line_num);
+                        Value::MakeContinuationValue(paused), stmt->line_num);
       break;
   }
 }
@@ -1277,8 +1289,8 @@ void StepStmt() {
 auto GetMember(Address a, const std::string& f, int line_num) -> Address {
   const Value* v = state->heap.Read(a, line_num);
   switch (v->tag) {
-    case ValKind::StructV: {
-      auto a = FindTupleField(f, v->GetStruct().inits);
+    case ValKind::StructValue: {
+      auto a = FindTupleField(f, v->GetStructValue().inits);
       if (a == std::nullopt) {
         std::cerr << "runtime error, member " << f << " not in ";
         PrintValue(v, std::cerr);
@@ -1287,7 +1299,7 @@ auto GetMember(Address a, const std::string& f, int line_num) -> Address {
       }
       return *a;
     }
-    case ValKind::TupleV: {
+    case ValKind::TupleValue: {
       auto a = FindTupleField(f, v);
       if (a == std::nullopt) {
         std::cerr << "field " << f << " not in ";
@@ -1297,14 +1309,15 @@ auto GetMember(Address a, const std::string& f, int line_num) -> Address {
       }
       return *a;
     }
-    case ValKind::ChoiceTV: {
+    case ValKind::ChoiceType: {
       if (FindInVarValues(f, v->GetChoiceType().alternatives) == nullptr) {
         std::cerr << "alternative " << f << " not in ";
         PrintValue(v, std::cerr);
         std::cerr << std::endl;
         exit(-1);
       }
-      auto ac = Value::MakeAltCons(f, *v->GetChoiceType().name);
+      auto ac =
+          Value::MakeAlternativeConstructorValue(f, *v->GetChoiceType().name);
       return state->heap.AllocateValue(ac);
     }
     default:
@@ -1361,7 +1374,7 @@ void Step() {
       auto del = MakeDeleteAct(a);
       frame->todo.Pop(1);
       InsertDelete(del, frame->todo);
-      frame->todo.Push(MakeValAct(Value::MakePtrVal(a)));
+      frame->todo.Push(MakeValAct(Value::MakePointerValue(a)));
       break;
     }
     case ActionKind::ValAction: {
@@ -1390,9 +1403,9 @@ auto InterpProgram(std::list<Declaration>* fs) -> int {
   }
   InitGlobals(fs);
 
-  const Expression* arg = Expression::MakeTuple(0, {});
-  const Expression* call_main =
-      Expression::MakeCall(0, Expression::MakeVar(0, "main"), arg);
+  const Expression* arg = Expression::MakeTupleLiteral(0, {});
+  const Expression* call_main = Expression::MakeCallExpression(
+      0, Expression::MakeIdentifierExpression(0, "main"), arg);
   auto todo = Stack(MakeExpAct(call_main));
   auto* scope = new Scope(globals, std::list<std::string>());
   auto* frame = new Frame("top", Stack(scope), todo);
diff --git a/executable_semantics/interpreter/typecheck.cpp b/executable_semantics/interpreter/typecheck.cpp
index c3053e257d09..04175c519079 100644
--- a/executable_semantics/interpreter/typecheck.cpp
+++ b/executable_semantics/interpreter/typecheck.cpp
@@ -32,7 +32,7 @@ void ExpectType(int line_num, const std::string& context, const Value* expected,
 
 void ExpectPointerType(int line_num, const std::string& context,
                        const Value* actual) {
-  if (actual->tag != ValKind::PointerTV) {
+  if (actual->tag != ValKind::PointerType) {
     std::cerr << line_num << ": type error in " << context << std::endl;
     std::cerr << "expected a pointer type\n";
     std::cerr << "actual: ";
@@ -56,35 +56,35 @@ void PrintTypeEnv(TypeEnv types, std::ostream& out) {
 auto ReifyType(const Value* t, int line_num) -> const Expression* {
   switch (t->tag) {
     case ValKind::VarTV:
-      return Expression::MakeVar(0, *t->GetVariableType());
-    case ValKind::IntTV:
-      return Expression::MakeIntType(0);
-    case ValKind::BoolTV:
-      return Expression::MakeBoolType(0);
-    case ValKind::TypeTV:
-      return Expression::MakeTypeType(0);
-    case ValKind::ContinuationTV:
-      return Expression::MakeContinuationType(0);
-    case ValKind::FunctionTV:
-      return Expression::MakeFunType(
+      return Expression::MakeIdentifierExpression(0, *t->GetVariableType());
+    case ValKind::IntType:
+      return Expression::MakeIntTypeLiteral(0);
+    case ValKind::BoolType:
+      return Expression::MakeBoolTypeLiteral(0);
+    case ValKind::TypeType:
+      return Expression::MakeTypeTypeLiteral(0);
+    case ValKind::ContinuationType:
+      return Expression::MakeContinuationTypeLiteral(0);
+    case ValKind::FunctionType:
+      return Expression::MakeFunctionTypeLiteral(
           0, ReifyType(t->GetFunctionType().param, line_num),
           ReifyType(t->GetFunctionType().ret, line_num));
-    case ValKind::TupleV: {
+    case ValKind::TupleValue: {
       std::vector<FieldInitializer> args;
-      for (const TupleElement& field : *t->GetTuple().elements) {
+      for (const TupleElement& field : *t->GetTupleValue().elements) {
         args.push_back(
             {.name = field.name,
              .expression = ReifyType(state->heap.Read(field.address, line_num),
                                      line_num)});
       }
-      return Expression::MakeTuple(0, args);
+      return Expression::MakeTupleLiteral(0, args);
     }
-    case ValKind::StructTV:
-      return Expression::MakeVar(0, *t->GetStructType().name);
-    case ValKind::ChoiceTV:
-      return Expression::MakeVar(0, *t->GetChoiceType().name);
-    case ValKind::PointerTV:
-      return Expression::MakeOp(
+    case ValKind::StructType:
+      return Expression::MakeIdentifierExpression(0, *t->GetStructType().name);
+    case ValKind::ChoiceType:
+      return Expression::MakeIdentifierExpression(0, *t->GetChoiceType().name);
+    case ValKind::PointerType:
+      return Expression::MakePrimitiveOperatorExpression(
           0, Operator::Ptr, {ReifyType(t->GetPointerType().type, line_num)});
     default:
       std::cerr << line_num << ": expected a type, not ";
@@ -135,7 +135,7 @@ auto TypeCheckExp(const Expression* e, TypeEnv types, Env values,
     std::cout << std::endl;
   }
   switch (e->tag()) {
-    case ExpressionKind::PatternVariable: {
+    case ExpressionKind::PatternVariableExpression: {
       if (context != TCContext::PatternContext) {
         std::cerr
             << e->line_num
@@ -144,8 +144,8 @@ auto TypeCheckExp(const Expression* e, TypeEnv types, Env values,
             << std::endl;
         exit(-1);
       }
-      auto t = InterpExp(values, e->GetPatternVariable().type);
-      if (t->tag == ValKind::AutoTV) {
+      auto t = InterpExp(values, e->GetPatternVariableExpression().type);
+      if (t->tag == ValKind::AutoType) {
         if (expected == nullptr) {
           std::cerr << e->line_num
                     << ": compilation error, auto not allowed here"
@@ -157,18 +157,19 @@ auto TypeCheckExp(const Expression* e, TypeEnv types, Env values,
       } else if (expected) {
         ExpectType(e->line_num, "pattern variable", t, expected);
       }
-      auto new_e = Expression::MakeVarPat(
-          e->line_num, e->GetPatternVariable().name, ReifyType(t, e->line_num));
-      types.Set(e->GetPatternVariable().name, t);
+      auto new_e = Expression::MakePatternVariableExpression(
+          e->line_num, e->GetPatternVariableExpression().name,
+          ReifyType(t, e->line_num));
+      types.Set(e->GetPatternVariableExpression().name, t);
       return TCResult(new_e, t, types);
     }
-    case ExpressionKind::Index: {
-      auto res = TypeCheckExp(e->GetIndex().aggregate, types, values, nullptr,
-                              TCContext::ValueContext);
+    case ExpressionKind::IndexExpression: {
+      auto res = TypeCheckExp(e->GetIndexExpression().aggregate, types, values,
+                              nullptr, TCContext::ValueContext);
       auto t = res.type;
       switch (t->tag) {
-        case ValKind::TupleV: {
-          auto i = ToInteger(InterpExp(values, e->GetIndex().offset));
+        case ValKind::TupleValue: {
+          auto i = ToInteger(InterpExp(values, e->GetIndexExpression().offset));
           std::string f = std::to_string(i);
           std::optional<Address> field_address = FindTupleField(f, t);
           if (field_address == std::nullopt) {
@@ -179,8 +180,8 @@ auto TypeCheckExp(const Expression* e, TypeEnv types, Env values,
             exit(-1);
           }
           auto field_t = state->heap.Read(*field_address, e->line_num);
-          auto new_e = Expression::MakeIndex(
-              e->line_num, res.exp, Expression::MakeInt(e->line_num, i));
+          auto new_e = Expression::MakeIndexExpression(
+              e->line_num, res.exp, Expression::MakeIntLiteral(e->line_num, i));
           return TCResult(new_e, field_t, res.types);
         }
         default:
@@ -189,36 +190,37 @@ auto TypeCheckExp(const Expression* e, TypeEnv types, Env values,
           exit(-1);
       }
     }
-    case ExpressionKind::Tuple: {
+    case ExpressionKind::TupleLiteral: {
       std::vector<FieldInitializer> new_args;
       auto arg_types = new std::vector<TupleElement>();
       auto new_types = types;
-      if (expected && expected->tag != ValKind::TupleV) {
+      if (expected && expected->tag != ValKind::TupleValue) {
         std::cerr << e->line_num << ": compilation error, didn't expect a tuple"
                   << std::endl;
         exit(-1);
       }
-      if (expected && e->GetTuple().fields.size() !=
-                          expected->GetTuple().elements->size()) {
+      if (expected && e->GetTupleLiteral().fields.size() !=
+                          expected->GetTupleValue().elements->size()) {
         std::cerr << e->line_num
                   << ": compilation error, tuples of different length"
                   << std::endl;
         exit(-1);
       }
       int i = 0;
-      for (auto arg = e->GetTuple().fields.begin();
-           arg != e->GetTuple().fields.end(); ++arg, ++i) {
+      for (auto arg = e->GetTupleLiteral().fields.begin();
+           arg != e->GetTupleLiteral().fields.end(); ++arg, ++i) {
         const Value* arg_expected = nullptr;
-        if (expected && expected->tag == ValKind::TupleV) {
-          if ((*expected->GetTuple().elements)[i].name != arg->name) {
+        if (expected && expected->tag == ValKind::TupleValue) {
+          if ((*expected->GetTupleValue().elements)[i].name != arg->name) {
             std::cerr << e->line_num
                       << ": compilation error, field names do not match, "
-                      << "expected " << (*expected->GetTuple().elements)[i].name
+                      << "expected "
+                      << (*expected->GetTupleValue().elements)[i].name
                       << " but got " << arg->name << std::endl;
             exit(-1);
           }
           arg_expected = state->heap.Read(
-              (*expected->GetTuple().elements)[i].address, e->line_num);
+              (*expected->GetTupleValue().elements)[i].address, e->line_num);
         }
         auto arg_res = TypeCheckExp(arg->expression, new_types, values,
                                     arg_expected, context);
@@ -228,42 +230,42 @@ auto TypeCheckExp(const Expression* e, TypeEnv types, Env values,
             {.name = arg->name,
              .address = state->heap.AllocateValue(arg_res.type)});
       }
-      auto tuple_e = Expression::MakeTuple(e->line_num, new_args);
-      auto tuple_t = Value::MakeTupleVal(arg_types);
+      auto tuple_e = Expression::MakeTupleLiteral(e->line_num, new_args);
+      auto tuple_t = Value::MakeTupleValue(arg_types);
       return TCResult(tuple_e, tuple_t, new_types);
     }
-    case ExpressionKind::GetField: {
-      auto res = TypeCheckExp(e->GetFieldAccess().aggregate, types, values,
-                              nullptr, TCContext::ValueContext);
+    case ExpressionKind::FieldAccessExpression: {
+      auto res = TypeCheckExp(e->GetFieldAccessExpression().aggregate, types,
+                              values, nullptr, TCContext::ValueContext);
       auto t = res.type;
       switch (t->tag) {
-        case ValKind::StructTV:
+        case ValKind::StructType:
           // Search for a field
           for (auto& field : *t->GetStructType().fields) {
-            if (e->GetFieldAccess().field == field.first) {
-              const Expression* new_e = Expression::MakeGetField(
-                  e->line_num, res.exp, e->GetFieldAccess().field);
+            if (e->GetFieldAccessExpression().field == field.first) {
+              const Expression* new_e = Expression::MakeFieldAccessExpression(
+                  e->line_num, res.exp, e->GetFieldAccessExpression().field);
               return TCResult(new_e, field.second, res.types);
             }
           }
           // Search for a method
           for (auto& method : *t->GetStructType().methods) {
-            if (e->GetFieldAccess().field == method.first) {
-              const Expression* new_e = Expression::MakeGetField(
-                  e->line_num, res.exp, e->GetFieldAccess().field);
+            if (e->GetFieldAccessExpression().field == method.first) {
+              const Expression* new_e = Expression::MakeFieldAccessExpression(
+                  e->line_num, res.exp, e->GetFieldAccessExpression().field);
               return TCResult(new_e, method.second, res.types);
             }
           }
           std::cerr << e->line_num << ": compilation error, struct "
                     << *t->GetStructType().name
                     << " does not have a field named "
-                    << e->GetFieldAccess().field << std::endl;
+                    << e->GetFieldAccessExpression().field << std::endl;
           exit(-1);
-        case ValKind::TupleV:
-          for (const TupleElement& field : *t->GetTuple().elements) {
-            if (e->GetFieldAccess().field == field.name) {
-              auto new_e = Expression::MakeGetField(e->line_num, res.exp,
-                                                    e->GetFieldAccess().field);
+        case ValKind::TupleValue:
+          for (const TupleElement& field : *t->GetTupleValue().elements) {
+            if (e->GetFieldAccessExpression().field == field.name) {
+              auto new_e = Expression::MakeFieldAccessExpression(
+                  e->line_num, res.exp, e->GetFieldAccessExpression().field);
               return TCResult(new_e,
                               state->heap.Read(field.address, e->line_num),
                               res.types);
@@ -272,22 +274,22 @@ auto TypeCheckExp(const Expression* e, TypeEnv types, Env values,
           std::cerr << e->line_num << ": compilation error, struct "
                     << *t->GetStructType().name
                     << " does not have a field named "
-                    << e->GetFieldAccess().field << std::endl;
+                    << e->GetFieldAccessExpression().field << std::endl;
           exit(-1);
-        case ValKind::ChoiceTV:
+        case ValKind::ChoiceType:
           for (auto vt = t->GetChoiceType().alternatives->begin();
                vt != t->GetChoiceType().alternatives->end(); ++vt) {
-            if (e->GetFieldAccess().field == vt->first) {
-              const Expression* new_e = Expression::MakeGetField(
-                  e->line_num, res.exp, e->GetFieldAccess().field);
-              auto fun_ty = Value::MakeFunTypeVal(vt->second, t);
+            if (e->GetFieldAccessExpression().field == vt->first) {
+              const Expression* new_e = Expression::MakeFieldAccessExpression(
+                  e->line_num, res.exp, e->GetFieldAccessExpression().field);
+              auto fun_ty = Value::MakeFunctionType(vt->second, t);
               return TCResult(new_e, fun_ty, res.types);
             }
           }
           std::cerr << e->line_num << ": compilation error, struct "
                     << *t->GetStructType().name
                     << " does not have a field named "
-                    << e->GetFieldAccess().field << std::endl;
+                    << e->GetFieldAccessExpression().field << std::endl;
           exit(-1);
 
         default:
@@ -299,91 +301,91 @@ auto TypeCheckExp(const Expression* e, TypeEnv types, Env values,
           exit(-1);
       }
     }
-    case ExpressionKind::Variable: {
-      std::optional<const Value*> type = types.Get(e->GetVariable().name);
+    case ExpressionKind::IdentifierExpression: {
+      std::optional<const Value*> type =
+          types.Get(e->GetIdentifierExpression().name);
       if (type) {
         return TCResult(e, *type, types);
       } else {
         std::cerr << e->line_num << ": could not find `"
-                  << e->GetVariable().name << "`" << std::endl;
+                  << e->GetIdentifierExpression().name << "`" << std::endl;
         exit(-1);
       }
     }
-    case ExpressionKind::Integer:
-      return TCResult(e, Value::MakeIntTypeVal(), types);
-    case ExpressionKind::Boolean:
-      return TCResult(e, Value::MakeBoolTypeVal(), types);
-    case ExpressionKind::PrimitiveOp: {
+    case ExpressionKind::IntLiteral:
+      return TCResult(e, Value::MakeIntType(), types);
+    case ExpressionKind::BoolLiteral:
+      return TCResult(e, Value::MakeBoolType(), types);
+    case ExpressionKind::PrimitiveOperatorExpression: {
       std::vector<const Expression*> es;
       std::vector<const Value*> ts;
       auto new_types = types;
-      for (const Expression* argument : e->GetPrimitiveOperator().arguments) {
+      for (const Expression* argument :
+           e->GetPrimitiveOperatorExpression().arguments) {
         auto res = TypeCheckExp(argument, types, values, nullptr,
                                 TCContext::ValueContext);
         new_types = res.types;
         es.push_back(res.exp);
         ts.push_back(res.type);
       }
-      auto new_e =
-          Expression::MakeOp(e->line_num, e->GetPrimitiveOperator().op, es);
-      switch (e->GetPrimitiveOperator().op) {
+      auto new_e = Expression::MakePrimitiveOperatorExpression(
+          e->line_num, e->GetPrimitiveOperatorExpression().op, es);
+      switch (e->GetPrimitiveOperatorExpression().op) {
         case Operator::Neg:
-          ExpectType(e->line_num, "negation", Value::MakeIntTypeVal(), ts[0]);
-          return TCResult(new_e, Value::MakeIntTypeVal(), new_types);
+          ExpectType(e->line_num, "negation", Value::MakeIntType(), ts[0]);
+          return TCResult(new_e, Value::MakeIntType(), new_types);
         case Operator::Add:
-          ExpectType(e->line_num, "addition(1)", Value::MakeIntTypeVal(),
-                     ts[0]);
-          ExpectType(e->line_num, "addition(2)", Value::MakeIntTypeVal(),
-                     ts[1]);
-          return TCResult(new_e, Value::MakeIntTypeVal(), new_types);
+          ExpectType(e->line_num, "addition(1)", Value::MakeIntType(), ts[0]);
+          ExpectType(e->line_num, "addition(2)", Value::MakeIntType(), ts[1]);
+          return TCResult(new_e, Value::MakeIntType(), new_types);
         case Operator::Sub:
-          ExpectType(e->line_num, "subtraction(1)", Value::MakeIntTypeVal(),
+          ExpectType(e->line_num, "subtraction(1)", Value::MakeIntType(),
                      ts[0]);
-          ExpectType(e->line_num, "subtraction(2)", Value::MakeIntTypeVal(),
+          ExpectType(e->line_num, "subtraction(2)", Value::MakeIntType(),
                      ts[1]);
-          return TCResult(new_e, Value::MakeIntTypeVal(), new_types);
+          return TCResult(new_e, Value::MakeIntType(), new_types);
         case Operator::Mul:
-          ExpectType(e->line_num, "multiplication(1)", Value::MakeIntTypeVal(),
+          ExpectType(e->line_num, "multiplication(1)", Value::MakeIntType(),
                      ts[0]);
-          ExpectType(e->line_num, "multiplication(2)", Value::MakeIntTypeVal(),
+          ExpectType(e->line_num, "multiplication(2)", Value::MakeIntType(),
                      ts[1]);
-          return TCResult(new_e, Value::MakeIntTypeVal(), new_types);
+          return TCResult(new_e, Value::MakeIntType(), new_types);
         case Operator::And:
-          ExpectType(e->line_num, "&&(1)", Value::MakeBoolTypeVal(), ts[0]);
-          ExpectType(e->line_num, "&&(2)", Value::MakeBoolTypeVal(), ts[1]);
-          return TCResult(new_e, Value::MakeBoolTypeVal(), new_types);
+          ExpectType(e->line_num, "&&(1)", Value::MakeBoolType(), ts[0]);
+          ExpectType(e->line_num, "&&(2)", Value::MakeBoolType(), ts[1]);
+          return TCResult(new_e, Value::MakeBoolType(), new_types);
         case Operator::Or:
-          ExpectType(e->line_num, "||(1)", Value::MakeBoolTypeVal(), ts[0]);
-          ExpectType(e->line_num, "||(2)", Value::MakeBoolTypeVal(), ts[1]);
-          return TCResult(new_e, Value::MakeBoolTypeVal(), new_types);
+          ExpectType(e->line_num, "||(1)", Value::MakeBoolType(), ts[0]);
+          ExpectType(e->line_num, "||(2)", Value::MakeBoolType(), ts[1]);
+          return TCResult(new_e, Value::MakeBoolType(), new_types);
         case Operator::Not:
-          ExpectType(e->line_num, "!", Value::MakeBoolTypeVal(), ts[0]);
-          return TCResult(new_e, Value::MakeBoolTypeVal(), new_types);
+          ExpectType(e->line_num, "!", Value::MakeBoolType(), ts[0]);
+          return TCResult(new_e, Value::MakeBoolType(), new_types);
         case Operator::Eq:
           ExpectType(e->line_num, "==", ts[0], ts[1]);
-          return TCResult(new_e, Value::MakeBoolTypeVal(), new_types);
+          return TCResult(new_e, Value::MakeBoolType(), new_types);
         case Operator::Deref:
           ExpectPointerType(e->line_num, "*", ts[0]);
           return TCResult(new_e, ts[0]->GetPointerType().type, new_types);
         case Operator::Ptr:
-          ExpectType(e->line_num, "*", Value::MakeTypeTypeVal(), ts[0]);
-          return TCResult(new_e, Value::MakeTypeTypeVal(), new_types);
+          ExpectType(e->line_num, "*", Value::MakeTypeType(), ts[0]);
+          return TCResult(new_e, Value::MakeTypeType(), new_types);
       }
       break;
     }
-    case ExpressionKind::Call: {
-      auto fun_res = TypeCheckExp(e->GetCall().function, types, values, nullptr,
-                                  TCContext::ValueContext);
+    case ExpressionKind::CallExpression: {
+      auto fun_res = TypeCheckExp(e->GetCallExpression().function, types,
+                                  values, nullptr, TCContext::ValueContext);
       switch (fun_res.type->tag) {
-        case ValKind::FunctionTV: {
+        case ValKind::FunctionType: {
           auto fun_t = fun_res.type;
           auto arg_res =
-              TypeCheckExp(e->GetCall().argument, fun_res.types, values,
-                           fun_t->GetFunctionType().param, context);
+              TypeCheckExp(e->GetCallExpression().argument, fun_res.types,
+                           values, fun_t->GetFunctionType().param, context);
           ExpectType(e->line_num, "call", fun_t->GetFunctionType().param,
                      arg_res.type);
-          auto new_e =
-              Expression::MakeCall(e->line_num, fun_res.exp, arg_res.exp);
+          auto new_e = Expression::MakeCallExpression(e->line_num, fun_res.exp,
+                                                      arg_res.exp);
           return TCResult(new_e, fun_t->GetFunctionType().ret, arg_res.types);
         }
         default: {
@@ -397,40 +399,40 @@ auto TypeCheckExp(const Expression* e, TypeEnv types, Env values,
       }
       break;
     }
-    case ExpressionKind::FunctionT: {
+    case ExpressionKind::FunctionTypeLiteral: {
       switch (context) {
         case TCContext::ValueContext:
         case TCContext::TypeContext: {
-          auto pt = InterpExp(values, e->GetFunctionType().parameter);
-          auto rt = InterpExp(values, e->GetFunctionType().return_type);
-          auto new_e =
-              Expression::MakeFunType(e->line_num, ReifyType(pt, e->line_num),
-                                      ReifyType(rt, e->line_num));
-          return TCResult(new_e, Value::MakeTypeTypeVal(), types);
+          auto pt = InterpExp(values, e->GetFunctionTypeLiteral().parameter);
+          auto rt = InterpExp(values, e->GetFunctionTypeLiteral().return_type);
+          auto new_e = Expression::MakeFunctionTypeLiteral(
+              e->line_num, ReifyType(pt, e->line_num),
+              ReifyType(rt, e->line_num));
+          return TCResult(new_e, Value::MakeTypeType(), types);
         }
         case TCContext::PatternContext: {
-          auto param_res = TypeCheckExp(e->GetFunctionType().parameter, types,
-                                        values, nullptr, context);
+          auto param_res = TypeCheckExp(e->GetFunctionTypeLiteral().parameter,
+                                        types, values, nullptr, context);
           auto ret_res =
-              TypeCheckExp(e->GetFunctionType().return_type, param_res.types,
-                           values, nullptr, context);
-          auto new_e = Expression::MakeFunType(
+              TypeCheckExp(e->GetFunctionTypeLiteral().return_type,
+                           param_res.types, values, nullptr, context);
+          auto new_e = Expression::MakeFunctionTypeLiteral(
               e->line_num, ReifyType(param_res.type, e->line_num),
               ReifyType(ret_res.type, e->line_num));
-          return TCResult(new_e, Value::MakeTypeTypeVal(), ret_res.types);
+          return TCResult(new_e, Value::MakeTypeType(), ret_res.types);
         }
       }
     }
-    case ExpressionKind::IntT:
-      return TCResult(e, Value::MakeTypeTypeVal(), types);
-    case ExpressionKind::BoolT:
-      return TCResult(e, Value::MakeTypeTypeVal(), types);
-    case ExpressionKind::TypeT:
-      return TCResult(e, Value::MakeTypeTypeVal(), types);
-    case ExpressionKind::AutoT:
-      return TCResult(e, Value::MakeTypeTypeVal(), types);
-    case ExpressionKind::ContinuationT:
-      return TCResult(e, Value::MakeTypeTypeVal(), types);
+    case ExpressionKind::IntTypeLiteral:
+      return TCResult(e, Value::MakeTypeType(), types);
+    case ExpressionKind::BoolTypeLiteral:
+      return TCResult(e, Value::MakeTypeType(), types);
+    case ExpressionKind::TypeTypeLiteral:
+      return TCResult(e, Value::MakeTypeType(), types);
+    case ExpressionKind::AutoTypeLiteral:
+      return TCResult(e, Value::MakeTypeType(), types);
+    case ExpressionKind::ContinuationTypeLiteral:
+      return TCResult(e, Value::MakeTypeType(), types);
   }
 }
 
@@ -474,7 +476,7 @@ auto TypeCheckStmt(const Statement* s, TypeEnv types, Env values,
     case StatementKind::While: {
       auto cnd_res = TypeCheckExp(s->GetWhile().cond, types, values, nullptr,
                                   TCContext::ValueContext);
-      ExpectType(s->line_num, "condition of `while`", Value::MakeBoolTypeVal(),
+      ExpectType(s->line_num, "condition of `while`", Value::MakeBoolType(),
                  cnd_res.type);
       auto body_res =
           TypeCheckStmt(s->GetWhile().body, types, values, ret_type);
@@ -532,7 +534,7 @@ auto TypeCheckStmt(const Statement* s, TypeEnv types, Env values,
     case StatementKind::If: {
       auto cnd_res = TypeCheckExp(s->GetIf().cond, types, values, nullptr,
                                   TCContext::ValueContext);
-      ExpectType(s->line_num, "condition of `if`", Value::MakeBoolTypeVal(),
+      ExpectType(s->line_num, "condition of `if`", Value::MakeBoolType(),
                  cnd_res.type);
       auto thn_res =
           TypeCheckStmt(s->GetIf().then_stmt, types, values, ret_type);
@@ -545,7 +547,7 @@ auto TypeCheckStmt(const Statement* s, TypeEnv types, Env values,
     case StatementKind::Return: {
       auto res = TypeCheckExp(s->GetReturn(), types, values, nullptr,
                               TCContext::ValueContext);
-      if (ret_type->tag == ValKind::AutoTV) {
+      if (ret_type->tag == ValKind::AutoType) {
         // The following infers the return type from the first 'return'
         // statement. This will get more difficult with subtyping, when we
         // should infer the least-upper bound of all the 'return' statements.
@@ -562,7 +564,7 @@ auto TypeCheckStmt(const Statement* s, TypeEnv types, Env values,
           s->line_num, *s->GetContinuation().continuation_variable,
           body_result.stmt);
       types.Set(*s->GetContinuation().continuation_variable,
-                Value::MakeContinuationTypeVal());
+                Value::MakeContinuationType());
       return TCStatement(new_continuation, types);
     }
     case StatementKind::Run: {
@@ -570,7 +572,7 @@ auto TypeCheckStmt(const Statement* s, TypeEnv types, Env values,
           TypeCheckExp(s->GetRun().argument, types, values, nullptr,
                        TCContext::ValueContext);
       ExpectType(s->line_num, "argument of `run`",
-                 Value::MakeContinuationTypeVal(), argument_result.type);
+                 Value::MakeContinuationType(), argument_result.type);
       const Statement* new_run =
           Statement::MakeRun(s->line_num, argument_result.exp);
       return TCStatement(new_run, types);
@@ -587,7 +589,7 @@ auto CheckOrEnsureReturn(const Statement* stmt, bool void_return, int line_num)
   if (!stmt) {
     if (void_return) {
       return Statement::MakeReturn(line_num,
-                                   Expression::MakeTuple(line_num, {}));
+                                   Expression::MakeTupleLiteral(line_num, {}));
     } else {
       std::cerr
           << "control-flow reaches end of non-void function without a return"
@@ -643,8 +645,8 @@ auto CheckOrEnsureReturn(const Statement* stmt, bool void_return, int line_num)
       if (void_return) {
         return Statement::MakeSeq(
             stmt->line_num, stmt,
-            Statement::MakeReturn(stmt->line_num,
-                                  Expression::MakeTuple(stmt->line_num, {})));
+            Statement::MakeReturn(stmt->line_num, Expression::MakeTupleLiteral(
+                                                      stmt->line_num, {})));
       } else {
         std::cerr
             << stmt->line_num
@@ -662,7 +664,7 @@ auto TypeCheckFunDef(const FunctionDefinition* f, TypeEnv types, Env values)
                                 TCContext::PatternContext);
   auto return_type = InterpExp(values, f->return_type);
   if (f->name == "main") {
-    ExpectType(f->line_num, "return type of `main`", Value::MakeIntTypeVal(),
+    ExpectType(f->line_num, "return type of `main`", Value::MakeIntType(),
                return_type);
     // TODO: Check that main doesn't have any parameters.
   }
@@ -679,11 +681,11 @@ auto TypeOfFunDef(TypeEnv types, Env values, const FunctionDefinition* fun_def)
   auto param_res = TypeCheckExp(fun_def->param_pattern, types, values, nullptr,
                                 TCContext::PatternContext);
   auto ret = InterpExp(values, fun_def->return_type);
-  if (ret->tag == ValKind::AutoTV) {
+  if (ret->tag == ValKind::AutoType) {
     auto f = TypeCheckFunDef(fun_def, types, values);
     ret = InterpExp(values, f->return_type);
   }
-  return Value::MakeFunTypeVal(param_res.type, ret);
+  return Value::MakeFunctionType(param_res.type, ret);
 }
 
 auto TypeOfStructDef(const StructDefinition* sd, TypeEnv /*types*/, Env ct_top)
@@ -696,7 +698,7 @@ auto TypeOfStructDef(const StructDefinition* sd, TypeEnv /*types*/, Env ct_top)
       fields->push_back(std::make_pair(*(*m)->u.field.name, t));
     }
   }
-  return Value::MakeStructTypeVal(*sd->name, fields, methods);
+  return Value::MakeStructType(*sd->name, fields, methods);
 }
 
 auto FunctionDeclaration::Name() const -> std::string {
@@ -779,7 +781,7 @@ auto StructDeclaration::TopLevel(TypeCheckContext& tops) const -> void {
     field_types->push_back({.name = field_name,
                             .address = state->heap.AllocateValue(field_value)});
   }
-  auto fun_ty = Value::MakeFunTypeVal(Value::MakeTupleVal(field_types), st);
+  auto fun_ty = Value::MakeFunctionType(Value::MakeTupleValue(field_types), st);
   tops.types.Set(Name(), fun_ty);
 }
 
@@ -789,7 +791,7 @@ auto ChoiceDeclaration::TopLevel(TypeCheckContext& tops) const -> void {
     auto t = InterpExp(tops.values, signature);
     alts->push_back(std::make_pair(name, t));
   }
-  auto ct = Value::MakeChoiceTypeVal(name, alts);
+  auto ct = Value::MakeChoiceType(name, alts);
   Address a = state->heap.AllocateValue(ct);
   tops.values.Set(Name(), a);  // Is this obsolete?
   tops.types.Set(Name(), ct);
diff --git a/executable_semantics/interpreter/value.cpp b/executable_semantics/interpreter/value.cpp
index a3f6e66fe110..204648e9fa9b 100644
--- a/executable_semantics/interpreter/value.cpp
+++ b/executable_semantics/interpreter/value.cpp
@@ -12,43 +12,43 @@
 
 namespace Carbon {
 
-int Value::GetInteger() const {
-  CHECK(tag == ValKind::IntV);
+int Value::GetIntValue() const {
+  CHECK(tag == ValKind::IntValue);
   return u.integer;
 }
 
-bool Value::GetBoolean() const {
-  CHECK(tag == ValKind::BoolV);
+bool Value::GetBoolValue() const {
+  CHECK(tag == ValKind::BoolValue);
   return u.boolean;
 }
 
-Function Value::GetFunction() const {
-  CHECK(tag == ValKind::FunV);
+FunctionValue Value::GetFunctionValue() const {
+  CHECK(tag == ValKind::FunctionValue);
   return u.fun;
 }
 
-StructConstructor Value::GetStruct() const {
-  CHECK(tag == ValKind::StructV);
+StructValue Value::GetStructValue() const {
+  CHECK(tag == ValKind::StructValue);
   return u.struct_val;
 }
 
-AlternativeConstructor Value::GetAlternativeConstructor() const {
-  CHECK(tag == ValKind::AltConsV);
+AlternativeConstructorValue Value::GetAlternativeConstructorValue() const {
+  CHECK(tag == ValKind::AlternativeConstructorValue);
   return u.alt_cons;
 }
 
-Alternative Value::GetAlternative() const {
-  CHECK(tag == ValKind::AltV);
+AlternativeValue Value::GetAlternativeValue() const {
+  CHECK(tag == ValKind::AlternativeValue);
   return u.alt;
 }
 
-TupleValue Value::GetTuple() const {
-  CHECK(tag == ValKind::TupleV);
+TupleValue Value::GetTupleValue() const {
+  CHECK(tag == ValKind::TupleValue);
   return u.tuple;
 }
 
-Address Value::GetPointer() const {
-  CHECK(tag == ValKind::PtrV);
+Address Value::GetPointerValue() const {
+  CHECK(tag == ValKind::PointerValue);
   return u.ptr;
 }
 
@@ -57,33 +57,33 @@ std::string* Value::GetVariableType() const {
   return u.var_type;
 }
 
-VariablePatternValue Value::GetVariablePattern() const {
-  CHECK(tag == ValKind::VarPatV);
+PatternVariableValue Value::GetPatternVariableValue() const {
+  CHECK(tag == ValKind::PatternVariableValue);
   return u.var_pat;
 }
 
-FunctionTypeValue Value::GetFunctionType() const {
-  CHECK(tag == ValKind::FunctionTV);
+FunctionType Value::GetFunctionType() const {
+  CHECK(tag == ValKind::FunctionType);
   return u.fun_type;
 }
 
 PointerType Value::GetPointerType() const {
-  CHECK(tag == ValKind::PointerTV);
+  CHECK(tag == ValKind::PointerType);
   return u.ptr_type;
 }
 
 StructType Value::GetStructType() const {
-  CHECK(tag == ValKind::StructTV);
+  CHECK(tag == ValKind::StructType);
   return u.struct_type;
 }
 
 ChoiceType Value::GetChoiceType() const {
-  CHECK(tag == ValKind::ChoiceTV);
+  CHECK(tag == ValKind::ChoiceType);
   return u.choice_type;
 }
 
-ContinuationValue Value::GetContinuation() const {
-  CHECK(tag == ValKind::ContinuationV);
+ContinuationValue Value::GetContinuationValue() const {
+  CHECK(tag == ValKind::ContinuationValue);
   return u.continuation;
 }
 
@@ -116,8 +116,8 @@ auto FieldsEqual(VarValues* ts1, VarValues* ts2) -> bool {
 
 auto FindTupleField(const std::string& name, const Value* tuple)
     -> std::optional<Address> {
-  CHECK(tuple->tag == ValKind::TupleV);
-  for (const TupleElement& element : *tuple->GetTuple().elements) {
+  CHECK(tuple->tag == ValKind::TupleValue);
+  for (const TupleElement& element : *tuple->GetTupleValue().elements) {
     if (element.name == name) {
       return element.address;
     }
@@ -125,67 +125,69 @@ auto FindTupleField(const std::string& name, const Value* tuple)
   return std::nullopt;
 }
 
-auto Value::MakeIntVal(int i) -> const Value* {
+auto Value::MakeIntValue(int i) -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::IntV;
+  v->tag = ValKind::IntValue;
   v->u.integer = i;
   return v;
 }
 
-auto Value::MakeBoolVal(bool b) -> const Value* {
+auto Value::MakeBoolValue(bool b) -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::BoolV;
+  v->tag = ValKind::BoolValue;
   v->u.boolean = b;
   return v;
 }
 
-auto Value::MakeFunVal(std::string name, const Value* param,
-                       const Statement* body) -> const Value* {
+auto Value::MakeFunctionValue(std::string name, const Value* param,
+                              const Statement* body) -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::FunV;
+  v->tag = ValKind::FunctionValue;
   v->u.fun.name = new std::string(std::move(name));
   v->u.fun.param = param;
   v->u.fun.body = body;
   return v;
 }
 
-auto Value::MakePtrVal(Address addr) -> const Value* {
+auto Value::MakePointerValue(Address addr) -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::PtrV;
+  v->tag = ValKind::PointerValue;
   v->u.ptr = addr;
   return v;
 }
 
-auto Value::MakeStructVal(const Value* type, const Value* inits)
+auto Value::MakeStructValue(const Value* type, const Value* inits)
     -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::StructV;
+  v->tag = ValKind::StructValue;
   v->u.struct_val.type = type;
   v->u.struct_val.inits = inits;
   return v;
 }
 
-auto Value::MakeTupleVal(std::vector<TupleElement>* elements) -> const Value* {
+auto Value::MakeTupleValue(std::vector<TupleElement>* elements)
+    -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::TupleV;
+  v->tag = ValKind::TupleValue;
   v->u.tuple.elements = elements;
   return v;
 }
 
-auto Value::MakeAltVal(std::string alt_name, std::string choice_name,
-                       Address argument) -> const Value* {
+auto Value::MakeAlternativeValue(std::string alt_name, std::string choice_name,
+                                 Address argument) -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::AltV;
+  v->tag = ValKind::AlternativeValue;
   v->u.alt.alt_name = new std::string(std::move(alt_name));
   v->u.alt.choice_name = new std::string(std::move(choice_name));
   v->u.alt.argument = argument;
   return v;
 }
 
-auto Value::MakeAltCons(std::string alt_name, std::string choice_name)
+auto Value::MakeAlternativeConstructorValue(std::string alt_name,
+                                            std::string choice_name)
     -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::AltConsV;
+  v->tag = ValKind::AlternativeConstructorValue;
   v->u.alt.alt_name = new std::string(std::move(alt_name));
   v->u.alt.choice_name = new std::string(std::move(choice_name));
   return v;
@@ -193,16 +195,17 @@ auto Value::MakeAltCons(std::string alt_name, std::string choice_name)
 
 // Return a first-class continuation represented a fragment
 // of the stack.
-auto Value::MakeContinuation(std::vector<Frame*> stack) -> Value* {
+auto Value::MakeContinuationValue(std::vector<Frame*> stack) -> Value* {
   auto* v = new Value();
-  v->tag = ValKind::ContinuationV;
+  v->tag = ValKind::ContinuationValue;
   v->u.continuation.stack = new std::vector<Frame*>(stack);
   return v;
 }
 
-auto Value::MakeVarPatVal(std::string name, const Value* type) -> const Value* {
+auto Value::MakePatternVariableValue(std::string name, const Value* type)
+    -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::VarPatV;
+  v->tag = ValKind::PatternVariableValue;
   v->u.var_pat.name = new std::string(std::move(name));
   v->u.var_pat.type = type;
   return v;
@@ -215,57 +218,57 @@ auto Value::MakeVarTypeVal(std::string name) -> const Value* {
   return v;
 }
 
-auto Value::MakeIntTypeVal() -> const Value* {
+auto Value::MakeIntType() -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::IntTV;
+  v->tag = ValKind::IntType;
   return v;
 }
 
-auto Value::MakeBoolTypeVal() -> const Value* {
+auto Value::MakeBoolType() -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::BoolTV;
+  v->tag = ValKind::BoolType;
   return v;
 }
 
-auto Value::MakeTypeTypeVal() -> const Value* {
+auto Value::MakeTypeType() -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::TypeTV;
+  v->tag = ValKind::TypeType;
   return v;
 }
 
 // Return a Continuation type.
-auto Value::MakeContinuationTypeVal() -> const Value* {
+auto Value::MakeContinuationType() -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::ContinuationTV;
+  v->tag = ValKind::ContinuationType;
   return v;
 }
 
-auto Value::MakeAutoTypeVal() -> const Value* {
+auto Value::MakeAutoType() -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::AutoTV;
+  v->tag = ValKind::AutoType;
   return v;
 }
 
-auto Value::MakeFunTypeVal(const Value* param, const Value* ret)
+auto Value::MakeFunctionType(const Value* param, const Value* ret)
     -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::FunctionTV;
+  v->tag = ValKind::FunctionType;
   v->u.fun_type.param = param;
   v->u.fun_type.ret = ret;
   return v;
 }
 
-auto Value::MakePtrTypeVal(const Value* type) -> const Value* {
+auto Value::MakePointerType(const Value* type) -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::PointerTV;
+  v->tag = ValKind::PointerType;
   v->u.ptr_type.type = type;
   return v;
 }
 
-auto Value::MakeStructTypeVal(std::string name, VarValues* fields,
-                              VarValues* methods) -> const Value* {
+auto Value::MakeStructType(std::string name, VarValues* fields,
+                           VarValues* methods) -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::StructTV;
+  v->tag = ValKind::StructType;
   v->u.struct_type.name = new std::string(std::move(name));
   v->u.struct_type.fields = fields;
   v->u.struct_type.methods = methods;
@@ -274,16 +277,16 @@ auto Value::MakeStructTypeVal(std::string name, VarValues* fields,
 
 auto Value::MakeUnitTypeVal() -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::TupleV;
+  v->tag = ValKind::TupleValue;
   v->u.tuple.elements = new std::vector<TupleElement>();
   return v;
 }
 
-auto Value::MakeChoiceTypeVal(
+auto Value::MakeChoiceType(
     std::string name, std::list<std::pair<std::string, const Value*>>* alts)
     -> const Value* {
   auto* v = new Value();
-  v->tag = ValKind::ChoiceTV;
+  v->tag = ValKind::ChoiceType;
   // Transitional leak: when we get rid of all pointers, this will disappear.
   v->u.choice_type.name = new std::string(name);
   v->u.choice_type.alternatives = alts;
@@ -292,31 +295,31 @@ auto Value::MakeChoiceTypeVal(
 
 auto PrintValue(const Value* val, std::ostream& out) -> void {
   switch (val->tag) {
-    case ValKind::AltConsV: {
-      out << *val->GetAlternativeConstructor().choice_name << "."
-          << *val->GetAlternativeConstructor().alt_name;
+    case ValKind::AlternativeConstructorValue: {
+      out << *val->GetAlternativeConstructorValue().choice_name << "."
+          << *val->GetAlternativeConstructorValue().alt_name;
       break;
     }
-    case ValKind::VarPatV: {
-      PrintValue(val->GetVariablePattern().type, out);
-      out << ": " << *val->GetVariablePattern().name;
+    case ValKind::PatternVariableValue: {
+      PrintValue(val->GetPatternVariableValue().type, out);
+      out << ": " << *val->GetPatternVariableValue().name;
       break;
     }
-    case ValKind::AltV: {
-      out << "alt " << *val->GetAlternative().choice_name << "."
-          << *val->GetAlternative().alt_name << " ";
-      state->heap.PrintAddress(val->GetAlternative().argument, out);
+    case ValKind::AlternativeValue: {
+      out << "alt " << *val->GetAlternativeValue().choice_name << "."
+          << *val->GetAlternativeValue().alt_name << " ";
+      state->heap.PrintAddress(val->GetAlternativeValue().argument, out);
       break;
     }
-    case ValKind::StructV: {
-      out << *val->GetStruct().type->GetStructType().name;
-      PrintValue(val->GetStruct().inits, out);
+    case ValKind::StructValue: {
+      out << *val->GetStructValue().type->GetStructType().name;
+      PrintValue(val->GetStructValue().inits, out);
       break;
     }
-    case ValKind::TupleV: {
+    case ValKind::TupleValue: {
       out << "(";
       bool add_commas = false;
-      for (const TupleElement& element : *val->GetTuple().elements) {
+      for (const TupleElement& element : *val->GetTupleValue().elements) {
         if (add_commas) {
           out << ", ";
         } else {
@@ -329,38 +332,38 @@ auto PrintValue(const Value* val, std::ostream& out) -> void {
       out << ")";
       break;
     }
-    case ValKind::IntV:
-      out << val->GetInteger();
+    case ValKind::IntValue:
+      out << val->GetIntValue();
       break;
-    case ValKind::BoolV:
-      out << std::boolalpha << val->GetBoolean();
+    case ValKind::BoolValue:
+      out << std::boolalpha << val->GetBoolValue();
       break;
-    case ValKind::FunV:
-      out << "fun<" << *val->GetFunction().name << ">";
+    case ValKind::FunctionValue:
+      out << "fun<" << *val->GetFunctionValue().name << ">";
       break;
-    case ValKind::PtrV:
-      out << "ptr<" << val->GetPointer() << ">";
+    case ValKind::PointerValue:
+      out << "ptr<" << val->GetPointerValue() << ">";
       break;
-    case ValKind::BoolTV:
+    case ValKind::BoolType:
       out << "Bool";
       break;
-    case ValKind::IntTV:
+    case ValKind::IntType:
       out << "Int";
       break;
-    case ValKind::TypeTV:
+    case ValKind::TypeType:
       out << "Type";
       break;
-    case ValKind::AutoTV:
+    case ValKind::AutoType:
       out << "auto";
       break;
-    case ValKind::ContinuationTV:
+    case ValKind::ContinuationType:
       out << "Continuation";
       break;
-    case ValKind::PointerTV:
+    case ValKind::PointerType:
       PrintValue(val->GetPointerType().type, out);
       out << "*";
       break;
-    case ValKind::FunctionTV:
+    case ValKind::FunctionType:
       out << "fn ";
       PrintValue(val->GetFunctionType().param, out);
       out << " -> ";
@@ -369,15 +372,15 @@ auto PrintValue(const Value* val, std::ostream& out) -> void {
     case ValKind::VarTV:
       out << *val->GetVariableType();
       break;
-    case ValKind::StructTV:
+    case ValKind::StructType:
       out << "struct " << *val->GetStructType().name;
       break;
-    case ValKind::ChoiceTV:
+    case ValKind::ChoiceType:
       out << "choice " << *val->GetChoiceType().name;
       break;
-    case ValKind::ContinuationV:
+    case ValKind::ContinuationValue:
       out << "continuation[[";
-      for (Frame* frame : *val->GetContinuation().stack) {
+      for (Frame* frame : *val->GetContinuationValue().stack) {
         PrintFrame(frame, out);
         out << " :: ";
       }
@@ -393,37 +396,39 @@ auto TypeEqual(const Value* t1, const Value* t2) -> bool {
   switch (t1->tag) {
     case ValKind::VarTV:
       return *t1->GetVariableType() == *t2->GetVariableType();
-    case ValKind::PointerTV:
+    case ValKind::PointerType:
       return TypeEqual(t1->GetPointerType().type, t2->GetPointerType().type);
-    case ValKind::FunctionTV:
+    case ValKind::FunctionType:
       return TypeEqual(t1->GetFunctionType().param,
                        t2->GetFunctionType().param) &&
              TypeEqual(t1->GetFunctionType().ret, t2->GetFunctionType().ret);
-    case ValKind::StructTV:
+    case ValKind::StructType:
       return *t1->GetStructType().name == *t2->GetStructType().name;
-    case ValKind::ChoiceTV:
+    case ValKind::ChoiceType:
       return *t1->GetChoiceType().name == *t2->GetChoiceType().name;
-    case ValKind::TupleV: {
-      if (t1->GetTuple().elements->size() != t2->GetTuple().elements->size()) {
+    case ValKind::TupleValue: {
+      if (t1->GetTupleValue().elements->size() !=
+          t2->GetTupleValue().elements->size()) {
         return false;
       }
-      for (size_t i = 0; i < t1->GetTuple().elements->size(); ++i) {
-        if ((*t1->GetTuple().elements)[i].name !=
-            (*t2->GetTuple().elements)[i].name) {
+      for (size_t i = 0; i < t1->GetTupleValue().elements->size(); ++i) {
+        if ((*t1->GetTupleValue().elements)[i].name !=
+            (*t2->GetTupleValue().elements)[i].name) {
           return false;
         }
         if (!TypeEqual(
-                state->heap.Read((*t1->GetTuple().elements)[i].address, 0),
-                state->heap.Read((*t2->GetTuple().elements)[i].address, 0))) {
+                state->heap.Read((*t1->GetTupleValue().elements)[i].address, 0),
+                state->heap.Read((*t2->GetTupleValue().elements)[i].address,
+                                 0))) {
           return false;
         }
       }
       return true;
     }
-    case ValKind::IntTV:
-    case ValKind::BoolTV:
-    case ValKind::ContinuationTV:
-    case ValKind::TypeTV:
+    case ValKind::IntType:
+    case ValKind::BoolType:
+    case ValKind::ContinuationType:
+    case ValKind::TypeType:
       return true;
     default:
       std::cerr << "TypeEqual used to compare non-type values" << std::endl;
@@ -465,34 +470,34 @@ auto ValueEqual(const Value* v1, const Value* v2, int line_num) -> bool {
     return false;
   }
   switch (v1->tag) {
-    case ValKind::IntV:
-      return v1->GetInteger() == v2->GetInteger();
-    case ValKind::BoolV:
-      return v1->GetBoolean() == v2->GetBoolean();
-    case ValKind::PtrV:
-      return v1->GetPointer() == v2->GetPointer();
-    case ValKind::FunV:
-      return v1->GetFunction().body == v2->GetFunction().body;
-    case ValKind::TupleV:
-      return FieldsValueEqual(v1->GetTuple().elements, v2->GetTuple().elements,
-                              line_num);
+    case ValKind::IntValue:
+      return v1->GetIntValue() == v2->GetIntValue();
+    case ValKind::BoolValue:
+      return v1->GetBoolValue() == v2->GetBoolValue();
+    case ValKind::PointerValue:
+      return v1->GetPointerValue() == v2->GetPointerValue();
+    case ValKind::FunctionValue:
+      return v1->GetFunctionValue().body == v2->GetFunctionValue().body;
+    case ValKind::TupleValue:
+      return FieldsValueEqual(v1->GetTupleValue().elements,
+                              v2->GetTupleValue().elements, line_num);
     default:
     case ValKind::VarTV:
-    case ValKind::IntTV:
-    case ValKind::BoolTV:
-    case ValKind::TypeTV:
-    case ValKind::FunctionTV:
-    case ValKind::PointerTV:
-    case ValKind::AutoTV:
-    case ValKind::StructTV:
-    case ValKind::ChoiceTV:
-    case ValKind::ContinuationTV:
+    case ValKind::IntType:
+    case ValKind::BoolType:
+    case ValKind::TypeType:
+    case ValKind::FunctionType:
+    case ValKind::PointerType:
+    case ValKind::AutoType:
+    case ValKind::StructType:
+    case ValKind::ChoiceType:
+    case ValKind::ContinuationType:
       return TypeEqual(v1, v2);
-    case ValKind::StructV:
-    case ValKind::AltV:
-    case ValKind::VarPatV:
-    case ValKind::AltConsV:
-    case ValKind::ContinuationV:
+    case ValKind::StructValue:
+    case ValKind::AlternativeValue:
+    case ValKind::PatternVariableValue:
+    case ValKind::AlternativeConstructorValue:
+    case ValKind::ContinuationValue:
       std::cerr << "ValueEqual does not support this kind of value."
                 << std::endl;
       exit(-1);
@@ -501,8 +506,8 @@ auto ValueEqual(const Value* v1, const Value* v2, int line_num) -> bool {
 
 auto ToInteger(const Value* v) -> int {
   switch (v->tag) {
-    case ValKind::IntV:
-      return v->GetInteger();
+    case ValKind::IntValue:
+      return v->GetIntValue();
     default:
       std::cerr << "expected an integer, not ";
       PrintValue(v, std::cerr);
diff --git a/executable_semantics/interpreter/value.h b/executable_semantics/interpreter/value.h
index 89d9c3ee9887..6e5eecdb04a3 100644
--- a/executable_semantics/interpreter/value.h
+++ b/executable_semantics/interpreter/value.h
@@ -37,47 +37,47 @@ struct TupleElement {
 };
 
 enum class ValKind {
-  IntV,
-  FunV,
-  PtrV,
-  BoolV,
-  StructV,
-  AltV,
-  TupleV,
+  IntValue,
+  FunctionValue,
+  PointerValue,
+  BoolValue,
+  StructValue,
+  AlternativeValue,
+  TupleValue,
   VarTV,
-  IntTV,
-  BoolTV,
-  TypeTV,
-  FunctionTV,
-  PointerTV,
-  AutoTV,
-  StructTV,
-  ChoiceTV,
-  ContinuationTV,  // The type of a continuation.
-  VarPatV,
-  AltConsV,
-  ContinuationV  // A first-class continuation value.
+  IntType,
+  BoolType,
+  TypeType,
+  FunctionType,
+  PointerType,
+  AutoType,
+  StructType,
+  ChoiceType,
+  ContinuationType,  // The type of a continuation.
+  PatternVariableValue,
+  AlternativeConstructorValue,
+  ContinuationValue  // A first-class continuation value.
 };
 
 struct Frame;  // used by continuation
 
-struct Function {
+struct FunctionValue {
   std::string* name;
   const Value* param;
   const Statement* body;
 };
 
-struct StructConstructor {
+struct StructValue {
   const Value* type;
   const Value* inits;
 };
 
-struct AlternativeConstructor {
+struct AlternativeConstructorValue {
   std::string* alt_name;
   std::string* choice_name;
 };
 
-struct Alternative {
+struct AlternativeValue {
   std::string* alt_name;
   std::string* choice_name;
   Address argument;
@@ -87,12 +87,12 @@ struct TupleValue {
   std::vector<TupleElement>* elements;
 };
 
-struct VariablePatternValue {
+struct PatternVariableValue {
   std::string* name;
   const Value* type;
 };
 
-struct FunctionTypeValue {
+struct FunctionType {
   const Value* param;
   const Value* ret;
 };
@@ -123,66 +123,67 @@ struct Value {
 
   // Return a first-class continuation represented by the
   // given stack, down to the nearest enclosing `__continuation`.
-  static auto MakeContinuation(std::vector<Frame*> stack) -> Value*;
-  static auto MakeIntVal(int i) -> const Value*;
-  static auto MakeBoolVal(bool b) -> const Value*;
-  static auto MakeFunVal(std::string name, const Value* param,
-                         const Statement* body) -> const Value*;
-  static auto MakePtrVal(Address addr) -> const Value*;
-  static auto MakeStructVal(const Value* type, const Value* inits)
+  static auto MakeContinuationValue(std::vector<Frame*> stack) -> Value*;
+  static auto MakeIntValue(int i) -> const Value*;
+  static auto MakeBoolValue(bool b) -> const Value*;
+  static auto MakeFunctionValue(std::string name, const Value* param,
+                                const Statement* body) -> const Value*;
+  static auto MakePointerValue(Address addr) -> const Value*;
+  static auto MakeStructValue(const Value* type, const Value* inits)
       -> const Value*;
-  static auto MakeTupleVal(std::vector<TupleElement>* elts) -> const Value*;
-  static auto MakeAltVal(std::string alt_name, std::string choice_name,
-                         Address argument) -> const Value*;
-  static auto MakeAltCons(std::string alt_name, std::string choice_name)
+  static auto MakeTupleValue(std::vector<TupleElement>* elts) -> const Value*;
+  static auto MakeAlternativeValue(std::string alt_name,
+                                   std::string choice_name, Address argument)
       -> const Value*;
-  static auto MakeVarPatVal(std::string name, const Value* type)
+  static auto MakeAlternativeConstructorValue(std::string alt_name,
+                                              std::string choice_name)
+      -> const Value*;
+  static auto MakePatternVariableValue(std::string name, const Value* type)
       -> const Value*;
   static auto MakeVarTypeVal(std::string name) -> const Value*;
-  static auto MakeIntTypeVal() -> const Value*;
-  static auto MakeContinuationTypeVal() -> const Value*;
-  static auto MakeAutoTypeVal() -> const Value*;
-  static auto MakeBoolTypeVal() -> const Value*;
-  static auto MakeTypeTypeVal() -> const Value*;
-  static auto MakeFunTypeVal(const Value* param, const Value* ret)
+  static auto MakeIntType() -> const Value*;
+  static auto MakeContinuationType() -> const Value*;
+  static auto MakeAutoType() -> const Value*;
+  static auto MakeBoolType() -> const Value*;
+  static auto MakeTypeType() -> const Value*;
+  static auto MakeFunctionType(const Value* param, const Value* ret)
       -> const Value*;
-  static auto MakePtrTypeVal(const Value* type) -> const Value*;
-  static auto MakeStructTypeVal(std::string name, VarValues* fields,
-                                VarValues* methods) -> const Value*;
+  static auto MakePointerType(const Value* type) -> const Value*;
+  static auto MakeStructType(std::string name, VarValues* fields,
+                             VarValues* methods) -> const Value*;
   static auto MakeUnitTypeVal() -> const Value*;
-  static auto MakeChoiceTypeVal(std::string name, VarValues* alts)
-      -> const Value*;
+  static auto MakeChoiceType(std::string name, VarValues* alts) -> const Value*;
 
   // Access to alternatives
-  int GetInteger() const;
-  bool GetBoolean() const;
-  Function GetFunction() const;
-  StructConstructor GetStruct() const;
-  AlternativeConstructor GetAlternativeConstructor() const;
-  Alternative GetAlternative() const;
-  TupleValue GetTuple() const;
-  Address GetPointer() const;
+  int GetIntValue() const;
+  bool GetBoolValue() const;
+  FunctionValue GetFunctionValue() const;
+  StructValue GetStructValue() const;
+  AlternativeConstructorValue GetAlternativeConstructorValue() const;
+  AlternativeValue GetAlternativeValue() const;
+  TupleValue GetTupleValue() const;
+  Address GetPointerValue() const;
   std::string* GetVariableType() const;
-  VariablePatternValue GetVariablePattern() const;
-  FunctionTypeValue GetFunctionType() const;
+  PatternVariableValue GetPatternVariableValue() const;
+  FunctionType GetFunctionType() const;
   PointerType GetPointerType() const;
   StructType GetStructType() const;
   ChoiceType GetChoiceType() const;
-  ContinuationValue GetContinuation() const;
+  ContinuationValue GetContinuationValue() const;
 
  private:
   union {
     int integer;
     bool boolean;
-    Function fun;
-    StructConstructor struct_val;
-    AlternativeConstructor alt_cons;
-    Alternative alt;
+    FunctionValue fun;
+    StructValue struct_val;
+    AlternativeConstructorValue alt_cons;
+    AlternativeValue alt;
     TupleValue tuple;
     Address ptr;
     std::string* var_type;
-    VariablePatternValue var_pat;
-    FunctionTypeValue fun_type;
+    PatternVariableValue var_pat;
+    FunctionType fun_type;
     PointerType ptr_type;
     StructType struct_type;
     ChoiceType choice_type;
diff --git a/executable_semantics/syntax/paren_contents.cpp b/executable_semantics/syntax/paren_contents.cpp
index d3efd619c015..9fb4c434f5ff 100644
--- a/executable_semantics/syntax/paren_contents.cpp
+++ b/executable_semantics/syntax/paren_contents.cpp
@@ -16,7 +16,7 @@ const Expression* ParenContents::AsExpression(int line_number) const {
 }
 
 const Expression* ParenContents::AsTuple(int line_number) const {
-  return Expression::MakeTuple(line_number, fields_);
+  return Expression::MakeTupleLiteral(line_number, fields_);
 }
 
 }  // namespace Carbon
diff --git a/executable_semantics/syntax/paren_contents_test.cpp b/executable_semantics/syntax/paren_contents_test.cpp
index 2fe90cec105e..db6bf61b242c 100644
--- a/executable_semantics/syntax/paren_contents_test.cpp
+++ b/executable_semantics/syntax/paren_contents_test.cpp
@@ -13,16 +13,16 @@ TEST(ParenContentsTest, EmptyAsExpression) {
   ParenContents contents;
   const Expression* expression = contents.AsExpression(/*line_num=*/1);
   EXPECT_EQ(expression->line_num, 1);
-  ASSERT_EQ(expression->tag(), ExpressionKind::Tuple);
-  EXPECT_EQ(expression->GetTuple().fields.size(), 0);
+  ASSERT_EQ(expression->tag(), ExpressionKind::TupleLiteral);
+  EXPECT_EQ(expression->GetTupleLiteral().fields.size(), 0);
 }
 
 TEST(ParenContentsTest, EmptyAsTuple) {
   ParenContents contents;
   const Expression* tuple = contents.AsTuple(/*line_num=*/1);
   EXPECT_EQ(tuple->line_num, 1);
-  ASSERT_EQ(tuple->tag(), ExpressionKind::Tuple);
-  EXPECT_EQ(tuple->GetTuple().fields.size(), 0);
+  ASSERT_EQ(tuple->tag(), ExpressionKind::TupleLiteral);
+  EXPECT_EQ(tuple->GetTupleLiteral().fields.size(), 0);
 }
 
 TEST(ParenContentsTest, UnaryNoCommaAsExpression) {
@@ -33,81 +33,81 @@ TEST(ParenContentsTest, UnaryNoCommaAsExpression) {
   // )
   // ```
   ParenContents contents(
-      {{.expression = Expression::MakeInt(/*line_num=*/2, 42)}},
+      {{.expression = Expression::MakeIntLiteral(/*line_num=*/2, 42)}},
       ParenContents::HasTrailingComma::No);
 
   const Expression* expression = contents.AsExpression(/*line_num=*/1);
   EXPECT_EQ(expression->line_num, 2);
-  ASSERT_EQ(expression->tag(), ExpressionKind::Integer);
+  ASSERT_EQ(expression->tag(), ExpressionKind::IntLiteral);
 }
 
 TEST(ParenContentsTest, UnaryNoCommaAsTuple) {
   ParenContents contents(
-      {{.expression = Expression::MakeInt(/*line_num=*/2, 42)}},
+      {{.expression = Expression::MakeIntLiteral(/*line_num=*/2, 42)}},
       ParenContents::HasTrailingComma::No);
 
   const Expression* tuple = contents.AsTuple(/*line_num=*/1);
   EXPECT_EQ(tuple->line_num, 1);
-  ASSERT_EQ(tuple->tag(), ExpressionKind::Tuple);
-  std::vector<FieldInitializer> fields = tuple->GetTuple().fields;
+  ASSERT_EQ(tuple->tag(), ExpressionKind::TupleLiteral);
+  std::vector<FieldInitializer> fields = tuple->GetTupleLiteral().fields;
   ASSERT_EQ(fields.size(), 1);
-  EXPECT_EQ(fields[0].expression->tag(), ExpressionKind::Integer);
+  EXPECT_EQ(fields[0].expression->tag(), ExpressionKind::IntLiteral);
 }
 
 TEST(ParenContentsTest, UnaryWithCommaAsExpression) {
   ParenContents contents(
-      {{.expression = Expression::MakeInt(/*line_num=*/2, 42)}},
+      {{.expression = Expression::MakeIntLiteral(/*line_num=*/2, 42)}},
       ParenContents::HasTrailingComma::Yes);
 
   const Expression* expression = contents.AsExpression(/*line_num=*/1);
   EXPECT_EQ(expression->line_num, 1);
-  ASSERT_EQ(expression->tag(), ExpressionKind::Tuple);
-  std::vector<FieldInitializer> fields = expression->GetTuple().fields;
+  ASSERT_EQ(expression->tag(), ExpressionKind::TupleLiteral);
+  std::vector<FieldInitializer> fields = expression->GetTupleLiteral().fields;
   ASSERT_EQ(fields.size(), 1);
-  EXPECT_EQ(fields[0].expression->tag(), ExpressionKind::Integer);
+  EXPECT_EQ(fields[0].expression->tag(), ExpressionKind::IntLiteral);
 }
 
 TEST(ParenContentsTest, UnaryWithCommaAsTuple) {
   ParenContents contents(
-      {{.expression = Expression::MakeInt(/*line_num=*/2, 42)}},
+      {{.expression = Expression::MakeIntLiteral(/*line_num=*/2, 42)}},
       ParenContents::HasTrailingComma::Yes);
 
   const Expression* tuple = contents.AsTuple(/*line_num=*/1);
   EXPECT_EQ(tuple->line_num, 1);
-  ASSERT_EQ(tuple->tag(), ExpressionKind::Tuple);
-  std::vector<FieldInitializer> fields = tuple->GetTuple().fields;
+  ASSERT_EQ(tuple->tag(), ExpressionKind::TupleLiteral);
+  std::vector<FieldInitializer> fields = tuple->GetTupleLiteral().fields;
   ASSERT_EQ(fields.size(), 1);
-  EXPECT_EQ(fields[0].expression->tag(), ExpressionKind::Integer);
+  EXPECT_EQ(fields[0].expression->tag(), ExpressionKind::IntLiteral);
 }
 
 TEST(ParenContentsTest, BinaryAsExpression) {
   ParenContents contents(
-      {{.expression = Expression::MakeInt(/*line_num=*/2, 42)},
-       {.expression = Expression::MakeInt(/*line_num=*/3, 42)}},
+      {{.expression = Expression::MakeIntLiteral(/*line_num=*/2, 42)},
+       {.expression = Expression::MakeIntLiteral(/*line_num=*/3, 42)}},
       ParenContents::HasTrailingComma::Yes);
 
   const Expression* expression = contents.AsExpression(/*line_num=*/1);
   EXPECT_EQ(expression->line_num, 1);
-  ASSERT_EQ(expression->tag(), ExpressionKind::Tuple);
-  std::vector<FieldInitializer> fields = expression->GetTuple().fields;
+  ASSERT_EQ(expression->tag(), ExpressionKind::TupleLiteral);
+  std::vector<FieldInitializer> fields = expression->GetTupleLiteral().fields;
   ASSERT_EQ(fields.size(), 2);
-  EXPECT_EQ(fields[0].expression->tag(), ExpressionKind::Integer);
-  EXPECT_EQ(fields[1].expression->tag(), ExpressionKind::Integer);
+  EXPECT_EQ(fields[0].expression->tag(), ExpressionKind::IntLiteral);
+  EXPECT_EQ(fields[1].expression->tag(), ExpressionKind::IntLiteral);
 }
 
 TEST(ParenContentsTest, BinaryAsTuple) {
   ParenContents contents(
-      {{.expression = Expression::MakeInt(/*line_num=*/2, 42)},
-       {.expression = Expression::MakeInt(/*line_num=*/3, 42)}},
+      {{.expression = Expression::MakeIntLiteral(/*line_num=*/2, 42)},
+       {.expression = Expression::MakeIntLiteral(/*line_num=*/3, 42)}},
       ParenContents::HasTrailingComma::Yes);
 
   const Expression* tuple = contents.AsTuple(/*line_num=*/1);
   EXPECT_EQ(tuple->line_num, 1);
-  ASSERT_EQ(tuple->tag(), ExpressionKind::Tuple);
-  std::vector<FieldInitializer> fields = tuple->GetTuple().fields;
+  ASSERT_EQ(tuple->tag(), ExpressionKind::TupleLiteral);
+  std::vector<FieldInitializer> fields = tuple->GetTupleLiteral().fields;
   ASSERT_EQ(fields.size(), 2);
-  EXPECT_EQ(fields[0].expression->tag(), ExpressionKind::Integer);
-  EXPECT_EQ(fields[1].expression->tag(), ExpressionKind::Integer);
+  EXPECT_EQ(fields[0].expression->tag(), ExpressionKind::IntLiteral);
+  EXPECT_EQ(fields[1].expression->tag(), ExpressionKind::IntLiteral);
 }
 
 }  // namespace
diff --git a/executable_semantics/syntax/parser.ypp b/executable_semantics/syntax/parser.ypp
index ac93264e0cec..f79a7473691e 100644
--- a/executable_semantics/syntax/parser.ypp
+++ b/executable_semantics/syntax/parser.ypp
@@ -201,58 +201,72 @@ pattern:
 ;
 expression:
   identifier
-    { $$ = Carbon::Expression::MakeVar(yylineno, $1); }
+    { $$ = Carbon::Expression::MakeIdentifierExpression(yylineno, $1); }
 | expression designator
-    { $$ = Carbon::Expression::MakeGetField(yylineno, $1, $2); }
+    { $$ = Carbon::Expression::MakeFieldAccessExpression(yylineno, $1, $2); }
 | expression "[" expression "]"
-    { $$ = Carbon::Expression::MakeIndex(yylineno, $1, $3); }
+    { $$ = Carbon::Expression::MakeIndexExpression(yylineno, $1, $3); }
 | identifier ":" expression
-    { $$ = Carbon::Expression::MakeVarPat(yylineno, $1, $3); }
+    {
+      $$ = Carbon::Expression::MakePatternVariableExpression(yylineno, $1, $3);
+    }
 | integer_literal
-    { $$ = Carbon::Expression::MakeInt(yylineno, $1); }
+    { $$ = Carbon::Expression::MakeIntLiteral(yylineno, $1); }
 | TRUE
-    { $$ = Carbon::Expression::MakeBool(yylineno, true); }
+    { $$ = Carbon::Expression::MakeBoolLiteral(yylineno, true); }
 | FALSE
-    { $$ = Carbon::Expression::MakeBool(yylineno, false); }
+    { $$ = Carbon::Expression::MakeBoolLiteral(yylineno, false); }
 | INT
-    { $$ = Carbon::Expression::MakeIntType(yylineno); }
+    { $$ = Carbon::Expression::MakeIntTypeLiteral(yylineno); }
 | BOOL
-    { $$ = Carbon::Expression::MakeBoolType(yylineno); }
+    { $$ = Carbon::Expression::MakeBoolTypeLiteral(yylineno); }
 | TYPE
-    { $$ = Carbon::Expression::MakeTypeType(yylineno); }
+    { $$ = Carbon::Expression::MakeTypeTypeLiteral(yylineno); }
 | AUTO
-    { $$ = Carbon::Expression::MakeAutoType(yylineno); }
+    { $$ = Carbon::Expression::MakeAutoTypeLiteral(yylineno); }
 | CONTINUATION_TYPE
-    { $$ = Carbon::Expression::MakeContinuationType(yylineno); }
+    { $$ = Carbon::Expression::MakeContinuationTypeLiteral(yylineno); }
 | paren_expression { $$ = $1; }
 | expression EQUAL_EQUAL expression
-    { $$ = Carbon::Expression::MakeOp(yylineno, Carbon::Operator::Eq, {$1, $3}); }
+    { $$ = Carbon::Expression::MakePrimitiveOperatorExpression(
+        yylineno, Carbon::Operator::Eq, {$1, $3}); }
 | expression "+" expression
-    { $$ = Carbon::Expression::MakeOp(yylineno, Carbon::Operator::Add, {$1, $3}); }
+    { $$ = Carbon::Expression::MakePrimitiveOperatorExpression(
+        yylineno, Carbon::Operator::Add, {$1, $3}); }
 | expression "-" expression
-    { $$ = Carbon::Expression::MakeOp(yylineno, Carbon::Operator::Sub, {$1, $3}); }
+    { $$ = Carbon::Expression::MakePrimitiveOperatorExpression(
+        yylineno, Carbon::Operator::Sub, {$1, $3}); }
 | expression BINARY_STAR expression
-    { $$ = Carbon::Expression::MakeOp(yylineno, Carbon::Operator::Mul, {$1, $3}); }
+    { $$ = Carbon::Expression::MakePrimitiveOperatorExpression(
+        yylineno, Carbon::Operator::Mul, {$1, $3}); }
 | expression AND expression
-    { $$ = Carbon::Expression::MakeOp(yylineno, Carbon::Operator::And, {$1, $3}); }
+    { $$ = Carbon::Expression::MakePrimitiveOperatorExpression(
+        yylineno, Carbon::Operator::And, {$1, $3}); }
 | expression OR expression
-    { $$ = Carbon::Expression::MakeOp(yylineno, Carbon::Operator::Or, {$1, $3}); }
+    { $$ = Carbon::Expression::MakePrimitiveOperatorExpression(
+        yylineno, Carbon::Operator::Or, {$1, $3}); }
 | NOT expression
-    { $$ = Carbon::Expression::MakeOp(yylineno, Carbon::Operator::Not, {$2}); }
+    { $$ = Carbon::Expression::MakePrimitiveOperatorExpression(
+        yylineno, Carbon::Operator::Not, {$2}); }
 | "-" expression %prec UNARY_MINUS
-    { $$ = Carbon::Expression::MakeOp(yylineno, Carbon::Operator::Neg, {$2}); }
+    { $$ = Carbon::Expression::MakePrimitiveOperatorExpression(
+        yylineno, Carbon::Operator::Neg, {$2}); }
 | PREFIX_STAR expression
-    { $$ = Carbon::Expression::MakeOp(yylineno, Carbon::Operator::Deref, {$2}); }
+    { $$ = Carbon::Expression::MakePrimitiveOperatorExpression(
+        yylineno, Carbon::Operator::Deref, {$2}); }
 | UNARY_STAR expression %prec PREFIX_STAR
-    { $$ = Carbon::Expression::MakeOp(yylineno, Carbon::Operator::Deref, {$2}); }
+    { $$ = Carbon::Expression::MakePrimitiveOperatorExpression(
+        yylineno, Carbon::Operator::Deref, {$2}); }
 | expression tuple
-    { $$ = Carbon::Expression::MakeCall(yylineno, $1, $2); }
+    { $$ = Carbon::Expression::MakeCallExpression(yylineno, $1, $2); }
 | expression POSTFIX_STAR
-    { $$ = Carbon::Expression::MakeOp(yylineno, Carbon::Operator::Ptr, {$1}); }
+    { $$ = Carbon::Expression::MakePrimitiveOperatorExpression(
+        yylineno, Carbon::Operator::Ptr, {$1}); }
 | expression UNARY_STAR
-    { $$ = Carbon::Expression::MakeOp(yylineno, Carbon::Operator::Ptr, {$1}); }
+    { $$ = Carbon::Expression::MakePrimitiveOperatorExpression(
+        yylineno, Carbon::Operator::Ptr, {$1}); }
 | FNTY tuple return_type
-    { $$ = Carbon::Expression::MakeFunType(yylineno, $2, $3); }
+    { $$ = Carbon::Expression::MakeFunctionTypeLiteral(yylineno, $2, $3); }
 ;
 designator: "." identifier { $$ = $2; }
 ;
@@ -296,8 +310,8 @@ clause:
     { $$ = new std::pair<const Carbon::Expression*, const Carbon::Statement*>($2, $4); }
 | DEFAULT DBLARROW statement
     {
-      auto vp = Carbon::Expression::MakeVarPat(yylineno, "_",
-                                   Carbon::Expression::MakeAutoType(yylineno));
+      auto vp = Carbon::Expression::MakePatternVariableExpression(
+          yylineno, "_", Carbon::Expression::MakeAutoTypeLiteral(yylineno));
       $$ = new std::pair<const Carbon::Expression*, const Carbon::Statement*>(vp, $3);
     }
 ;
@@ -350,7 +364,7 @@ statement_list:
 ;
 return_type:
   // Empty
-    { $$ = Carbon::Expression::MakeTuple(yylineno, {}); }
+    { $$ = Carbon::Expression::MakeTupleLiteral(yylineno, {}); }
 | ARROW expression %prec FNARROW
     { $$ = $2; }
 ;
@@ -359,8 +373,9 @@ function_definition:
     { $$ = MakeFunDef(yylineno, $2, $4, $3, $6); }
 | FN identifier tuple DBLARROW expression ";"
     {
-      $$ = Carbon::MakeFunDef(yylineno, $2, Carbon::Expression::MakeAutoType(yylineno), $3,
-                              Carbon::Statement::MakeReturn(yylineno, $5));
+      $$ = Carbon::MakeFunDef(yylineno, $2,
+                              Carbon::Expression::MakeAutoTypeLiteral(yylineno),
+                              $3, Carbon::Statement::MakeReturn(yylineno, $5));
     }
 ;
 function_declaration:
@@ -385,7 +400,7 @@ alternative:
 | identifier
     {
       $$ = std::pair<std::string, const Carbon::Expression*>(
-          $1, Carbon::Expression::MakeTuple(yylineno, {}));
+          $1, Carbon::Expression::MakeTupleLiteral(yylineno, {}));
     }
 ;
 alternative_list: