carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-10-04 18:51:09 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity

Add support for struct types, following p0561. (#856)

Browse Source
This commit is contained in:
Geoff Romer
2021-09-29 16:14:27 -07:00
committed by GitHub
parent d157d96338
commit c4e40aaa86
20 changed files with 674 additions and 44 deletions
Download Patch File Download Diff File Expand all files Collapse all files
executable_semantics/syntax/parser.ypp
+59 -2
View File
@@ -106,7 +106,9 @@
%type <Nonnull<Statement*>> if_statement
%type <std::optional<Nonnull<Statement*>>> optional_else
%type <std::pair<Nonnull<Expression*>, bool>> return_expression
%type <Nonnull<Statement*>> nonempty_block
%type <Nonnull<Statement*>> block
%type <Nonnull<Statement*>> nonempty_statement_list
%type <std::optional<Nonnull<Statement*>>> statement_list
%type <Nonnull<Expression*>> expression
%type <GenericBinding> generic_binding
@@ -116,6 +118,10 @@
%type <Nonnull<Pattern*>> non_expression_pattern
%type <std::pair<Nonnull<Expression*>, bool>> return_type
%type <Nonnull<Expression*>> paren_expression
%type <Nonnull<Expression*>> struct_literal
%type <std::vector<FieldInitializer>> struct_literal_contents
%type <Nonnull<Expression*>> struct_type_literal
%type <std::vector<FieldInitializer>> struct_type_literal_contents
%type <Nonnull<Expression*>> tuple
%type <std::optional<std::string>> binding_lhs
%type <Nonnull<BindingPattern*>> variable_declaration
@@ -299,6 +305,8 @@ expression:
| CONTINUATION_TYPE
{ $$ = arena->New<ContinuationTypeLiteral>(context.SourceLoc()); }
| paren_expression { $$ = $1; }
| struct_literal { $$ = $1; }
| struct_type_literal { $$ = $1; }
| expression EQUAL_EQUAL expression
{
$$ = arena->New<PrimitiveOperatorExpression>(
@@ -415,6 +423,40 @@ paren_expression_contents:
}
;
struct_literal:
LEFT_CURLY_BRACE struct_literal_contents RIGHT_CURLY_BRACE
{ $$ = arena->New<StructLiteral>(context.SourceLoc(), $2); }
| LEFT_CURLY_BRACE struct_literal_contents COMMA RIGHT_CURLY_BRACE
{ $$ = arena->New<StructLiteral>(context.SourceLoc(), $2); }
;
struct_literal_contents:
designator EQUAL expression
{ $$ = {FieldInitializer($1, $3)}; }
| struct_literal_contents COMMA designator EQUAL expression
{
$$ = $1;
$$.push_back(FieldInitializer($3, $5));
}
;
struct_type_literal:
LEFT_CURLY_BRACE RIGHT_CURLY_BRACE
{ $$ = arena->New<StructTypeLiteral>(context.SourceLoc()); }
| LEFT_CURLY_BRACE struct_type_literal_contents RIGHT_CURLY_BRACE
{ $$ = arena->New<StructTypeLiteral>(context.SourceLoc(), $2); }
| LEFT_CURLY_BRACE struct_type_literal_contents COMMA RIGHT_CURLY_BRACE
{ $$ = arena->New<StructTypeLiteral>(context.SourceLoc(), $2); }
;
struct_type_literal_contents:
designator COLON expression
{ $$ = {FieldInitializer($1, $3)}; }
| struct_type_literal_contents COMMA designator COLON expression
{
$$ = $1;
$$.push_back(FieldInitializer($3, $5));
}
;
// In many cases, using `pattern` recursively will result in ambiguities.
// When that happens, it's necessary to factor out two separate productions,
// one for when the sub-pattern is an expression, and one for when it is not.
@@ -499,6 +541,7 @@ maybe_empty_tuple_pattern:
| tuple_pattern
{ $$ = $1; }
;
clause:
CASE pattern DOUBLE_ARROW statement
{ $$ = Match::Clause($2, $4); }
@@ -539,7 +582,14 @@ statement:
auto [return_exp, is_omitted_exp] = $2;
$$ = arena->New<Return>(context.SourceLoc(), return_exp, is_omitted_exp);
}
| block
// We disallow empty blocks in places where an arbitrary statement can occur
// in order to avoid ambiguity with the empty struct literal `{}`. We can
// allow non-empty blocks because a non-empty struct literal always starts with
// a designator, and a block never does, so one token of lookahead suffices
// to disambiguate. As of this writing, the "official" resolution of this
// ambiguity is an open question (see
// https://github.com/carbon-language/carbon-lang/blob/trunk/docs/design/classes.md#literals)
| nonempty_block
{ $$ = $1; }
| MATCH LEFT_PARENTHESIS expression RIGHT_PARENTHESIS LEFT_CURLY_BRACE
clause_list RIGHT_CURLY_BRACE
@@ -572,13 +622,20 @@ return_expression:
statement_list:
// Empty
{ $$ = std::nullopt; }
| statement statement_list
| nonempty_statement_list
{ $$ = $1; }
;
nonempty_statement_list:
statement statement_list
{ $$ = arena->New<Sequence>(context.SourceLoc(), $1, $2); }
;
block:
LEFT_CURLY_BRACE statement_list RIGHT_CURLY_BRACE
{ $$ = arena->New<Block>(context.SourceLoc(), $2); }
;
nonempty_block:
LEFT_CURLY_BRACE nonempty_statement_list RIGHT_CURLY_BRACE
{ $$ = arena->New<Block>(context.SourceLoc(), $2); }
return_type:
// Empty
{ $$ = {arena->New<TupleLiteral>(context.SourceLoc()), true}; }