diff --git a/executable_semantics/ast/ast.h b/executable_semantics/ast/ast.h
index 646c863f64e0..eded57f578bf 100644
--- a/executable_semantics/ast/ast.h
+++ b/executable_semantics/ast/ast.h
@@ -5,7 +5,7 @@
 #ifndef EXECUTABLE_SEMANTICS_AST_AST_H_
 #define EXECUTABLE_SEMANTICS_AST_AST_H_
 
-#include <list>
+#include <vector>
 
 #include "executable_semantics/ast/declaration.h"
 #include "executable_semantics/ast/library_name.h"
@@ -22,7 +22,7 @@ struct AST {
   // Import directives.
   std::vector<LibraryName> imports;
   // The file's ordered declarations.
-  std::list<Ptr<const Declaration>> declarations;
+  std::vector<Ptr<const Declaration>> declarations;
 };
 
 }  // namespace Carbon
diff --git a/executable_semantics/ast/class_definition.h b/executable_semantics/ast/class_definition.h
index 18b1e6ae171e..a4d13db00168 100644
--- a/executable_semantics/ast/class_definition.h
+++ b/executable_semantics/ast/class_definition.h
@@ -5,8 +5,8 @@
 #ifndef EXECUTABLE_SEMANTICS_AST_CLASS_DEFINITION_H_
 #define EXECUTABLE_SEMANTICS_AST_CLASS_DEFINITION_H_
 
-#include <list>
 #include <string>
+#include <vector>
 
 #include "executable_semantics/ast/member.h"
 #include "executable_semantics/ast/source_location.h"
@@ -16,7 +16,7 @@ namespace Carbon {
 struct ClassDefinition {
   SourceLocation loc;
   std::string name;
-  std::list<Ptr<Member>> members;
+  std::vector<Ptr<Member>> members;
 };
 
 }  // namespace Carbon
diff --git a/executable_semantics/ast/declaration.h b/executable_semantics/ast/declaration.h
index aeac1114467a..e9eb959a0bde 100644
--- a/executable_semantics/ast/declaration.h
+++ b/executable_semantics/ast/declaration.h
@@ -5,8 +5,8 @@
 #ifndef EXECUTABLE_SEMANTICS_AST_DECLARATION_H_
 #define EXECUTABLE_SEMANTICS_AST_DECLARATION_H_
 
-#include <list>
 #include <string>
+#include <vector>
 
 #include "common/ostream.h"
 #include "executable_semantics/ast/class_definition.h"
@@ -77,7 +77,7 @@ class FunctionDeclaration : public Declaration {
 class ClassDeclaration : public Declaration {
  public:
   ClassDeclaration(SourceLocation loc, std::string name,
-                   std::list<Ptr<Member>> members)
+                   std::vector<Ptr<Member>> members)
       : Declaration(Kind::ClassDeclaration, loc),
         definition({.loc = loc,
                     .name = std::move(name),
@@ -97,7 +97,7 @@ class ChoiceDeclaration : public Declaration {
  public:
   ChoiceDeclaration(
       SourceLocation loc, std::string name,
-      std::list<std::pair<std::string, Ptr<const Expression>>> alternatives)
+      std::vector<std::pair<std::string, Ptr<const Expression>>> alternatives)
       : Declaration(Kind::ChoiceDeclaration, loc),
         name(std::move(name)),
         alternatives(std::move(alternatives)) {}
@@ -108,13 +108,13 @@ class ChoiceDeclaration : public Declaration {
 
   auto Name() const -> const std::string& { return name; }
   auto Alternatives() const
-      -> const std::list<std::pair<std::string, Ptr<const Expression>>>& {
+      -> const std::vector<std::pair<std::string, Ptr<const Expression>>>& {
     return alternatives;
   }
 
  private:
   std::string name;
-  std::list<std::pair<std::string, Ptr<const Expression>>> alternatives;
+  std::vector<std::pair<std::string, Ptr<const Expression>>> alternatives;
 };
 
 // Global variable definition implements the Declaration concept.
diff --git a/executable_semantics/ast/statement.h b/executable_semantics/ast/statement.h
index ac15a69fdfdd..c94cdb4c35cd 100644
--- a/executable_semantics/ast/statement.h
+++ b/executable_semantics/ast/statement.h
@@ -5,7 +5,7 @@
 #ifndef EXECUTABLE_SEMANTICS_AST_STATEMENT_H_
 #define EXECUTABLE_SEMANTICS_AST_STATEMENT_H_
 
-#include <list>
+#include <vector>
 
 #include "common/ostream.h"
 #include "executable_semantics/ast/expression.h"
@@ -225,8 +225,9 @@ class Continue : public Statement {
 
 class Match : public Statement {
  public:
-  Match(SourceLocation loc, Ptr<const Expression> exp,
-        std::list<std::pair<Ptr<const Pattern>, Ptr<const Statement>>> clauses)
+  Match(
+      SourceLocation loc, Ptr<const Expression> exp,
+      std::vector<std::pair<Ptr<const Pattern>, Ptr<const Statement>>> clauses)
       : Statement(Kind::Match, loc), exp(exp), clauses(std::move(clauses)) {}
 
   static auto classof(const Statement* stmt) -> bool {
@@ -234,14 +235,14 @@ class Match : public Statement {
   }
 
   auto Exp() const -> Ptr<const Expression> { return exp; }
-  auto Clauses() const
-      -> const std::list<std::pair<Ptr<const Pattern>, Ptr<const Statement>>>& {
+  auto Clauses() const -> const
+      std::vector<std::pair<Ptr<const Pattern>, Ptr<const Statement>>>& {
     return clauses;
   }
 
  private:
   Ptr<const Expression> exp;
-  std::list<std::pair<Ptr<const Pattern>, Ptr<const Statement>>> clauses;
+  std::vector<std::pair<Ptr<const Pattern>, Ptr<const Statement>>> clauses;
 };
 
 // A continuation statement.
diff --git a/executable_semantics/interpreter/exec_program.cpp b/executable_semantics/interpreter/exec_program.cpp
index e1afcde17547..90bd42e15d2c 100644
--- a/executable_semantics/interpreter/exec_program.cpp
+++ b/executable_semantics/interpreter/exec_program.cpp
@@ -15,7 +15,7 @@ namespace Carbon {
 
 // Adds builtins, currently only Print(). Note Print() is experimental, not
 // standardized, but is made available for printing state in tests.
-static void AddIntrinsics(std::list<Ptr<const Declaration>>* declarations) {
+static void AddIntrinsics(std::vector<Ptr<const Declaration>>* declarations) {
   SourceLocation loc("<intrinsic>", 0);
   std::vector<TuplePattern::Field> print_fields = {TuplePattern::Field(
       "0", global_arena->New<BindingPattern>(
@@ -50,7 +50,7 @@ void ExecProgram(AST ast) {
   TypeChecker::TypeCheckContext p = type_checker.TopLevel(ast.declarations);
   TypeEnv top = p.types;
   Env ct_top = p.values;
-  std::list<Ptr<const Declaration>> new_decls;
+  std::vector<Ptr<const Declaration>> new_decls;
   for (const auto decl : ast.declarations) {
     new_decls.push_back(type_checker.MakeTypeChecked(decl, top, ct_top));
   }
diff --git a/executable_semantics/interpreter/exec_program.h b/executable_semantics/interpreter/exec_program.h
index c4f42781ea45..51b3e6aca709 100644
--- a/executable_semantics/interpreter/exec_program.h
+++ b/executable_semantics/interpreter/exec_program.h
@@ -9,8 +9,6 @@
 #ifndef EXECUTABLE_SEMANTICS_INTERPRETER_EXEC_PROGRAM_H_
 #define EXECUTABLE_SEMANTICS_INTERPRETER_EXEC_PROGRAM_H_
 
-#include <list>
-
 #include "executable_semantics/ast/ast.h"
 
 namespace Carbon {
diff --git a/executable_semantics/interpreter/frame.h b/executable_semantics/interpreter/frame.h
index 599527135d38..b8d2b123d66c 100644
--- a/executable_semantics/interpreter/frame.h
+++ b/executable_semantics/interpreter/frame.h
@@ -5,8 +5,8 @@
 #ifndef EXECUTABLE_SEMANTICS_INTERPRETER_FRAME_H_
 #define EXECUTABLE_SEMANTICS_INTERPRETER_FRAME_H_
 
-#include <list>
 #include <string>
+#include <vector>
 
 #include "common/ostream.h"
 #include "executable_semantics/interpreter/action.h"
@@ -20,12 +20,12 @@ namespace Carbon {
 using Env = Dictionary<std::string, Address>;
 
 struct Scope {
-  explicit Scope(Env values) : Scope(values, std::list<std::string>()) {}
-  Scope(Env values, std::list<std::string> l)
+  explicit Scope(Env values) : Scope(values, std::vector<std::string>()) {}
+  Scope(Env values, std::vector<std::string> l)
       : values(values), locals(std::move(l)) {}
 
   Env values;
-  std::list<std::string> locals;
+  std::vector<std::string> locals;
 };
 
 // A frame represents either a function call or a delimited continuation.
diff --git a/executable_semantics/interpreter/interpreter.cpp b/executable_semantics/interpreter/interpreter.cpp
index 6a0e26b1b4b6..a61238460aa0 100644
--- a/executable_semantics/interpreter/interpreter.cpp
+++ b/executable_semantics/interpreter/interpreter.cpp
@@ -5,7 +5,6 @@
 #include "executable_semantics/interpreter/interpreter.h"
 
 #include <iterator>
-#include <list>
 #include <map>
 #include <optional>
 #include <utility>
@@ -174,7 +173,7 @@ void Interpreter::InitEnv(const Declaration& d, Env* env) {
   }
 }
 
-void Interpreter::InitGlobals(const std::list<Ptr<const Declaration>>& fs) {
+void Interpreter::InitGlobals(const std::vector<Ptr<const Declaration>>& fs) {
   for (const auto d : fs) {
     InitEnv(*d, &globals);
   }
@@ -772,14 +771,13 @@ auto Interpreter::StepStmt() -> Transition {
           frame->scopes.Pop();
           return Done{};
         }
-        auto c = match_stmt.Clauses().begin();
-        std::advance(c, clause_num);
+        auto c = match_stmt.Clauses()[clause_num];
 
         if (act->Pos() % 2 == 1) {
           // start interpreting the pattern of the clause
           //    { {v :: (match ([]) ...) :: C, E, F} :: S, H}
           // -> { {pi :: (match ([]) ...) :: C, E, F} :: S, H}
-          return Spawn{global_arena->New<PatternAction>(c->first)};
+          return Spawn{global_arena->New<PatternAction>(c.first)};
         } else {  // try to match
           auto v = act->Results()[0];
           auto pat = act->Results()[clause_num + 1];
@@ -792,7 +790,7 @@ auto Interpreter::StepStmt() -> Transition {
               frame->scopes.Top()->values.Set(name, value);
               frame->scopes.Top()->locals.push_back(name);
             }
-            return Spawn{global_arena->New<StatementAction>(c->second)};
+            return Spawn{global_arena->New<StatementAction>(c.second)};
           } else {
             return RunAgain{};
           }
@@ -1090,7 +1088,7 @@ class Interpreter::DoTransition {
         << "internal error in call_function, pattern match failed";
     // Create the new frame and push it on the stack
     Env values = interpreter->globals;
-    std::list<std::string> params;
+    std::vector<std::string> params;
     for (const auto& [name, value] : *matches) {
       values.Set(name, value);
       params.push_back(name);
@@ -1134,7 +1132,7 @@ void Interpreter::Step() {
   }  // switch
 }
 
-auto Interpreter::InterpProgram(const std::list<Ptr<const Declaration>>& fs)
+auto Interpreter::InterpProgram(const std::vector<Ptr<const Declaration>>& fs)
     -> int {
   // Check that the interpreter is in a clean state.
   CHECK(globals.IsEmpty());
diff --git a/executable_semantics/interpreter/interpreter.h b/executable_semantics/interpreter/interpreter.h
index a38cc7c4c5b5..6a2aba777abc 100644
--- a/executable_semantics/interpreter/interpreter.h
+++ b/executable_semantics/interpreter/interpreter.h
@@ -5,7 +5,6 @@
 #ifndef EXECUTABLE_SEMANTICS_INTERPRETER_INTERPRETER_H_
 #define EXECUTABLE_SEMANTICS_INTERPRETER_INTERPRETER_H_
 
-#include <list>
 #include <optional>
 #include <utility>
 #include <vector>
@@ -26,7 +25,7 @@ using Env = Dictionary<std::string, Address>;
 class Interpreter {
  public:
   // Interpret the whole program.
-  auto InterpProgram(const std::list<Ptr<const Declaration>>& fs) -> int;
+  auto InterpProgram(const std::vector<Ptr<const Declaration>>& fs) -> int;
 
   // Interpret an expression at compile-time.
   auto InterpExp(Env values, Ptr<const Expression> e) -> Ptr<const Value>;
@@ -124,7 +123,7 @@ class Interpreter {
   // State transition for statements.
   auto StepStmt() -> Transition;
 
-  void InitGlobals(const std::list<Ptr<const Declaration>>& fs);
+  void InitGlobals(const std::vector<Ptr<const Declaration>>& fs);
   auto CurrentEnv() -> Env;
   auto GetFromEnv(SourceLocation loc, const std::string& name) -> Address;
 
diff --git a/executable_semantics/interpreter/type_checker.cpp b/executable_semantics/interpreter/type_checker.cpp
index be4416d2861d..b90e9c4f029c 100644
--- a/executable_semantics/interpreter/type_checker.cpp
+++ b/executable_semantics/interpreter/type_checker.cpp
@@ -658,7 +658,7 @@ auto TypeChecker::TypeCheckStmt(Ptr<const Statement> s, TypeEnv types,
       const auto& match = cast<Match>(*s);
       auto res = TypeCheckExp(match.Exp(), types, values);
       auto res_type = res.type;
-      std::list<std::pair<Ptr<const Pattern>, Ptr<const Statement>>>
+      std::vector<std::pair<Ptr<const Pattern>, Ptr<const Statement>>>
           new_clauses;
       for (auto& clause : match.Clauses()) {
         new_clauses.push_back(TypeCheckCase(res_type, clause.first,
@@ -816,7 +816,7 @@ static auto CheckOrEnsureReturn(std::optional<Ptr<const Statement>> opt_stmt,
   switch (stmt->Tag()) {
     case Statement::Kind::Match: {
       const auto& match = cast<Match>(*stmt);
-      std::list<std::pair<Ptr<const Pattern>, Ptr<const Statement>>>
+      std::vector<std::pair<Ptr<const Pattern>, Ptr<const Statement>>>
           new_clauses;
       for (const auto& clause : match.Clauses()) {
         auto s = CheckOrEnsureReturn(clause.second, omitted_ret_type,
@@ -995,7 +995,7 @@ auto TypeChecker::MakeTypeChecked(const Ptr<const Declaration> d,
     case Declaration::Kind::ClassDeclaration: {
       const ClassDefinition& class_def =
           cast<ClassDeclaration>(*d).Definition();
-      std::list<Ptr<Member>> fields;
+      std::vector<Ptr<Member>> fields;
       for (Ptr<Member> m : class_def.members) {
         switch (m->Tag()) {
           case Member::Kind::FieldMember:
@@ -1091,7 +1091,7 @@ void TypeChecker::TopLevel(const Declaration& d, TypeCheckContext* tops) {
   }
 }
 
-auto TypeChecker::TopLevel(const std::list<Ptr<const Declaration>>& fs)
+auto TypeChecker::TopLevel(const std::vector<Ptr<const Declaration>>& fs)
     -> TypeCheckContext {
   TypeCheckContext tops;
   bool found_main = false;
diff --git a/executable_semantics/interpreter/type_checker.h b/executable_semantics/interpreter/type_checker.h
index f1dff7d9c473..186d682d5f27 100644
--- a/executable_semantics/interpreter/type_checker.h
+++ b/executable_semantics/interpreter/type_checker.h
@@ -30,7 +30,7 @@ class TypeChecker {
   auto MakeTypeChecked(const Ptr<const Declaration> d, const TypeEnv& types,
                        const Env& values) -> Ptr<const Declaration>;
 
-  auto TopLevel(const std::list<Ptr<const Declaration>>& fs)
+  auto TopLevel(const std::vector<Ptr<const Declaration>>& fs)
       -> TypeCheckContext;
 
  private:
diff --git a/executable_semantics/interpreter/value.h b/executable_semantics/interpreter/value.h
index 22de1039d2f9..9cb3cf89d4a0 100644
--- a/executable_semantics/interpreter/value.h
+++ b/executable_semantics/interpreter/value.h
@@ -5,7 +5,6 @@
 #ifndef EXECUTABLE_SEMANTICS_INTERPRETER_VALUE_H_
 #define EXECUTABLE_SEMANTICS_INTERPRETER_VALUE_H_
 
-#include <list>
 #include <optional>
 #include <string>
 #include <variant>
@@ -86,7 +85,7 @@ class Value {
   const Kind tag;
 };
 
-using VarValues = std::list<std::pair<std::string, Ptr<const Value>>>;
+using VarValues = std::vector<std::pair<std::string, Ptr<const Value>>>;
 
 auto FindInVarValues(const std::string& field, const VarValues& inits)
     -> std::optional<Ptr<const Value>>;
diff --git a/executable_semantics/syntax/parser.ypp b/executable_semantics/syntax/parser.ypp
index b03aebeb3b33..ff2ed05238ce 100644
--- a/executable_semantics/syntax/parser.ypp
+++ b/executable_semantics/syntax/parser.ypp
@@ -54,7 +54,6 @@
   #include <cstdarg>
   #include <cstdio>
   #include <cstdlib>
-  #include <list>
   #include <vector>
 
   #include "common/check.h"
@@ -101,7 +100,7 @@
 %type <BisonWrap<Ptr<const Declaration>>> declaration
 %type <BisonWrap<Ptr<const FunctionDefinition>>> function_declaration
 %type <BisonWrap<Ptr<const FunctionDefinition>>> function_definition
-%type <std::list<Ptr<const Declaration>>> declaration_list
+%type <std::vector<Ptr<const Declaration>>> declaration_list
 %type <BisonWrap<Ptr<const Statement>>> statement
 %type <BisonWrap<Ptr<const Statement>>> if_statement
 %type <std::optional<Ptr<const Statement>>> optional_else
@@ -120,7 +119,7 @@
 %type <std::optional<std::string>> binding_lhs
 %type <BisonWrap<Ptr<const BindingPattern>>> variable_declaration
 %type <BisonWrap<Ptr<Member>>> member
-%type <std::list<Ptr<Member>>> member_list
+%type <std::vector<Ptr<Member>>> member_list
 %type <BisonWrap<ParenContents<Expression>::Element>> paren_expression_element
 %type <ParenContents<Expression>> paren_expression_base
 %type <ParenContents<Expression>> paren_expression_contents
@@ -131,9 +130,10 @@
 %type <BisonWrap<ParenContents<Pattern>::Element>> paren_pattern_element
 %type <ParenContents<Pattern>> paren_pattern_contents
 %type <BisonWrap<std::pair<std::string, Ptr<const Expression>>>> alternative
-%type <std::list<std::pair<std::string, Ptr<const Expression>>>> alternative_list
+%type <std::vector<std::pair<std::string, Ptr<const Expression>>>> alternative_list
+%type <std::vector<std::pair<std::string, Ptr<const Expression>>>> alternative_list_contents
 %type <BisonWrap<std::pair<Ptr<const Pattern>, Ptr<const Statement>>>> clause
-%type <std::list<std::pair<Ptr<const Pattern>, Ptr<const Statement>>>> clause_list
+%type <std::vector<std::pair<Ptr<const Pattern>, Ptr<const Statement>>>> clause_list
 
 %token
   // Most tokens have their spelling defined in lexer.lpp.
@@ -516,11 +516,11 @@ clause:
 ;
 clause_list:
   // Empty
-    { $$ = std::list<std::pair<Ptr<const Pattern>, Ptr<const Statement>>>(); }
-| clause clause_list
+    { $$ = {}; }
+| clause_list clause
     {
-      $$ = $2;
-      $$.push_front($1);
+      $$ = $1;
+      $$.push_back($2);
     }
 ;
 statement:
@@ -651,11 +651,11 @@ member: VAR variable_declaration SEMICOLON
 ;
 member_list:
   // Empty
-    { $$ = std::list<Ptr<Member>>(); }
-| member member_list
+    { $$ = {}; }
+| member_list member
     {
-      $$ = $2;
-      $$.push_front($1);
+      $$ = $1;
+      $$.push_back($2);
     }
 ;
 alternative:
@@ -669,16 +669,19 @@ alternative:
 ;
 alternative_list:
   // Empty
-    { $$ = std::list<std::pair<std::string, Ptr<const Expression>>>(); }
-| alternative
+    { $$ = {}; }
+| alternative_list_contents
+    { $$ = $1; }
+| alternative_list_contents COMMA
+    { $$ = $1; }
+;
+alternative_list_contents:
+  alternative
+    { $$ = {$1}; }
+| alternative_list_contents COMMA alternative
     {
-      $$ = std::list<std::pair<std::string, Ptr<const Expression>>>();
-      $$.push_front($1);
-    }
-| alternative COMMA alternative_list
-    {
-      $$ = std::move($3);
-      $$.push_front($1);
+      $$ = $1;
+      $$.push_back($3);
     }
 ;
 declaration:
@@ -697,11 +700,11 @@ declaration:
 ;
 declaration_list:
   // Empty
-    { $$ = std::list<Ptr<const Declaration>>(); }
-| declaration declaration_list
+    { $$ = {}; }
+| declaration_list declaration
     {
-      $$ = $2;
-      $$.push_front(Ptr<const Declaration>($1));
+      $$ = $1;
+      $$.push_back(Ptr<const Declaration>($2));
     }
 ;
 %%