Files
carbon-lang/executable_semantics/ast/pattern.cpp
T
Jon Meow 70797e8bf8 Mass rename SourceLoc and Tag (#860)
This does a mass rename of:

-   `SourceLoc()` -> `source_loc()` for property naming
    - `loc` -> `source_loc_` for underscore+consistency
    - Generally changing function args to `source_loc` for consistency
-   `Tag()` -> `kind()` for property naming and `Kind` parity
    - `tag` -> `kind_` for underscore

Also renames `Pos` and `Results` on `Action`. These are a bit of an exception in that most base classes only have `Tag` and maybe `SourceLoc`, whereas `Action` has a little more. I felt okay having `source_loc()` and `kind()` on the base class where children do `Exp()` and the like, but it felt weird to me to mix it on the same class.

The reason for doing this cross-class in one PR is so that I can do it efficiently with a global replace in the codebase, rather than e.g. changing `Expression` but having to read through compiler errors to determine where it's calling `Expression`'s `Tag` versus a different `Tag`. The end result should be equivalent.
2021-09-29 16:52:12 -07:00

111 lines
3.7 KiB
C++

// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "executable_semantics/ast/pattern.h"
#include <string>
#include "common/ostream.h"
#include "executable_semantics/ast/expression.h"
#include "executable_semantics/common/arena.h"
#include "executable_semantics/common/error.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/Casting.h"
namespace Carbon {
using llvm::cast;
void Pattern::Print(llvm::raw_ostream& out) const {
switch (kind()) {
case Kind::AutoPattern:
out << "auto";
break;
case Kind::BindingPattern: {
const auto& binding = cast<BindingPattern>(*this);
if (binding.Name().has_value()) {
out << *binding.Name();
} else {
out << "_";
}
out << ": " << *binding.Type();
break;
}
case Kind::TuplePattern: {
const auto& tuple = cast<TuplePattern>(*this);
out << "(";
llvm::ListSeparator sep;
for (const TuplePattern::Field& field : tuple.Fields()) {
out << sep << field.name << " = " << *field.pattern;
}
out << ")";
break;
}
case Kind::AlternativePattern: {
const auto& alternative = cast<AlternativePattern>(*this);
out << *alternative.ChoiceType() << "." << alternative.AlternativeName()
<< *alternative.Arguments();
break;
}
case Kind::ExpressionPattern:
out << *cast<ExpressionPattern>(*this).Expression();
break;
}
}
auto PatternFromParenContents(Nonnull<Arena*> arena, SourceLocation source_loc,
const ParenContents<Pattern>& paren_contents)
-> Nonnull<Pattern*> {
std::optional<Nonnull<Pattern*>> single_term = paren_contents.SingleTerm();
if (single_term.has_value()) {
return *single_term;
} else {
return TuplePatternFromParenContents(arena, source_loc, paren_contents);
}
}
auto TuplePatternFromParenContents(Nonnull<Arena*> arena,
SourceLocation source_loc,
const ParenContents<Pattern>& paren_contents)
-> Nonnull<TuplePattern*> {
return arena->New<TuplePattern>(
source_loc,
paren_contents.TupleElements<TuplePattern::Field>(source_loc));
}
// Used by AlternativePattern for constructor initialization. Produces a helpful
// error for incorrect expressions, rather than letting a default cast error
// apply.
static auto RequireFieldAccess(Nonnull<Expression*> alternative)
-> FieldAccessExpression& {
if (alternative->kind() != Expression::Kind::FieldAccessExpression) {
FATAL_PROGRAM_ERROR(alternative->source_loc())
<< "Alternative pattern must have the form of a field access.";
}
return cast<FieldAccessExpression>(*alternative);
}
AlternativePattern::AlternativePattern(SourceLocation source_loc,
Nonnull<Expression*> alternative,
Nonnull<TuplePattern*> arguments)
: Pattern(Kind::AlternativePattern, source_loc),
choice_type(RequireFieldAccess(alternative).Aggregate()),
alternative_name(RequireFieldAccess(alternative).Field()),
arguments(arguments) {}
auto ParenExpressionToParenPattern(Nonnull<Arena*> arena,
const ParenContents<Expression>& contents)
-> ParenContents<Pattern> {
ParenContents<Pattern> result = {
.elements = {}, .has_trailing_comma = contents.has_trailing_comma};
for (const auto& element : contents.elements) {
result.elements.push_back(
{.name = element.name,
.term = arena->New<ExpressionPattern>(element.term)});
}
return result;
}
} // namespace Carbon