TypeRef Parse_Type_ErasedType(TokenStream& lex, bool allow_trait_list)
{
Token tok;
auto ps = lex.start_span();
::std::vector<Type_TraitPath> traits;
::std::vector<AST::LifetimeRef> lifetimes;
do {
if( LOOK_AHEAD(lex) == TOK_LIFETIME ) {
GET_TOK(tok, lex);
lifetimes.push_back(AST::LifetimeRef( /*lex.point_span(),*/ lex.get_ident(mv$(tok)) ));
}
else
{
AST::HigherRankedBounds hrbs;
if( lex.lookahead(0) == TOK_RWORD_FOR )
{
hrbs = Parse_HRB(lex);
}
traits.push_back({ mv$(hrbs), Parse_Path(lex, PATH_GENERIC_TYPE) });
}
} while( GET_TOK(tok, lex) == TOK_PLUS );
PUTBACK(tok, lex);
return TypeRef(lex.end_span(mv$(ps)), TypeData::make_ErasedType({ mv$(traits), mv$(lifetimes) }));
}
TypeRef Parse_Type_Path(TokenStream& lex, ::AST::HigherRankedBounds hrbs, bool allow_trait_list)
{
Token tok;
auto ps = lex.start_span();
if( hrbs.empty() && !allow_trait_list )
{
return TypeRef(TypeRef::TagPath(), lex.end_span(mv$(ps)), Parse_Path(lex, PATH_GENERIC_TYPE));
}
else
{
::std::vector<Type_TraitPath> traits;
::std::vector<AST::LifetimeRef> lifetimes;
traits.push_back(Type_TraitPath { mv$(hrbs), Parse_Path(lex, PATH_GENERIC_TYPE) });
if( allow_trait_list )
{
while( GET_TOK(tok, lex) == TOK_PLUS )
{
if( LOOK_AHEAD(lex) == TOK_LIFETIME ) {
GET_TOK(tok, lex);
lifetimes.push_back(AST::LifetimeRef( /*lex.point_span(),*/ lex.get_ident(mv$(tok)) ));
}
else
{
if( lex.lookahead(0) == TOK_RWORD_FOR )
{
hrbs = Parse_HRB(lex);
}
traits.push_back({ mv$(hrbs), Parse_Path(lex, PATH_GENERIC_TYPE) });
}
}
PUTBACK(tok, lex);
}
if( !traits[0].hrbs.empty() || traits.size() > 1 || lifetimes.size() > 0 )
{
if( lifetimes.empty())
lifetimes.push_back(AST::LifetimeRef());
return TypeRef(lex.end_span(mv$(ps)), mv$(traits), mv$(lifetimes));
}
else
{
return TypeRef(TypeRef::TagPath(), lex.end_span(mv$(ps)), mv$(traits.at(0).path));
}
}
}
TypeRef Parse_Type_Int(TokenStream& lex, bool allow_trait_list)
{
//TRACE_FUNCTION;
auto ps = lex.start_span();
Token tok;
switch( GET_TOK(tok, lex) )
{
case TOK_INTERPOLATED_TYPE:
return mv$(tok.frag_type());
// '!' - Only ever used as part of function prototypes, but is kinda a type... not allowed here though
case TOK_EXCLAM:
return TypeRef( Span(tok.get_pos()), TypeData::make_Bang({}) );
// '_' = Wildcard (type inferrence variable)
case TOK_UNDERSCORE:
return TypeRef(Span(tok.get_pos()));
// 'unsafe' - An unsafe function type
case TOK_RWORD_UNSAFE:
// 'extern' - A function type with an ABI
case TOK_RWORD_EXTERN:
// 'fn' - Rust function
case TOK_RWORD_FN:
PUTBACK(tok, lex);
return Parse_Type_Fn(lex);
case TOK_RWORD_IMPL:
return Parse_Type_ErasedType(lex, allow_trait_list);
// '<' - An associated type cast
case TOK_LT:
case TOK_DOUBLE_LT: {
PUTBACK(tok, lex);
auto path = Parse_Path(lex, PATH_GENERIC_TYPE);
return TypeRef(TypeRef::TagPath(), lex.end_span(mv$(ps)), mv$(path));
}
//
case TOK_RWORD_FOR: {
auto hrls = Parse_HRB(lex);
switch(LOOK_AHEAD(lex))
{
case TOK_RWORD_UNSAFE:
case TOK_RWORD_EXTERN:
case TOK_RWORD_FN:
return Parse_Type_Fn(lex, hrls);
default:
return Parse_Type_Path(lex, hrls, true);
}
}
// <ident> - Either a primitive, or a path
case TOK_IDENT:
if( lex.lookahead(0) == TOK_EXCLAM )
{
lex.getToken();
// TODO: path macros
return TypeRef(TypeRef::TagMacro(), Parse_MacroInvocation(ps, mv$(tok.str()), lex));
}
// or a primitive
//if( auto ct = coretype_fromstring(tok.str()) )
//{
// return TypeRef(TypeRef::TagPrimitive(), Span(tok.get_pos()), ct);
//}
PUTBACK(tok, lex);
return Parse_Type_Path(lex, {}, allow_trait_list);
// - Fall through to path handling
// '::' - Absolute path
case TOK_DOUBLE_COLON:
// 'self' - This relative path
case TOK_RWORD_SELF:
// 'super' - Parent relative path
case TOK_RWORD_SUPER:
// ':path' fragment
case TOK_INTERPOLATED_PATH:
PUTBACK(tok, lex);
return Parse_Type_Path(lex, {}, allow_trait_list);
// HACK! Convert && into & &
case TOK_DOUBLE_AMP:
lex.putback(Token(TOK_AMP));
// '&' - Reference type
case TOK_AMP: {
AST::LifetimeRef lifetime;
// Reference
tok = lex.getToken();
if( tok.type() == TOK_LIFETIME ) {
lifetime = AST::LifetimeRef(/*lex.point_span(), */lex.get_ident(::std::move(tok)));
tok = lex.getToken();
}
bool is_mut = false;
if( tok.type() == TOK_RWORD_MUT ) {
is_mut = true;
}
else {
PUTBACK(tok, lex);
}
return TypeRef(TypeRef::TagReference(), lex.end_span(mv$(ps)), ::std::move(lifetime), is_mut, Parse_Type(lex, false));
}
// '*' - Raw pointer
case TOK_STAR:
// Pointer
switch( GET_TOK(tok, lex) )
{
case TOK_RWORD_MUT:
// Mutable pointer
return TypeRef(TypeRef::TagPointer(), lex.end_span(mv$(ps)), true, Parse_Type(lex, false));
case TOK_RWORD_CONST:
// Immutable pointer
return TypeRef(TypeRef::TagPointer(), lex.end_span(mv$(ps)), false, Parse_Type(lex, false));
default:
throw ParseError::Unexpected(lex, tok, {TOK_RWORD_CONST, TOK_RWORD_MUT});
}
throw ParseError::BugCheck("Reached end of Parse_Type:STAR");
// '[' - Array type
case TOK_SQUARE_OPEN: {
// Array
TypeRef inner = Parse_Type(lex);
if( GET_TOK(tok, lex) == TOK_SEMICOLON ) {
// Sized array
AST::Expr array_size = Parse_Expr(lex);
GET_CHECK_TOK(tok, lex, TOK_SQUARE_CLOSE);
return TypeRef(TypeRef::TagSizedArray(), lex.end_span(mv$(ps)), mv$(inner), array_size.take_node());
}
else if( tok.type() == TOK_SQUARE_CLOSE )
{
return TypeRef(TypeRef::TagUnsizedArray(), lex.end_span(mv$(ps)), mv$(inner));
}
else {
throw ParseError::Unexpected(lex, tok/*, "; or ]"*/);
}
}
// '(' - Tuple (or lifetime bounded trait)
case TOK_PAREN_OPEN: {
DEBUG("Tuple");
if( GET_TOK(tok, lex) == TOK_PAREN_CLOSE )
return TypeRef(TypeRef::TagTuple(), lex.end_span(mv$(ps)), {});
PUTBACK(tok, lex);
TypeRef inner = Parse_Type(lex, true);
if( LOOK_AHEAD(lex) == TOK_PAREN_CLOSE )
{
// Type in parens, NOT a tuple
GET_CHECK_TOK(tok, lex, TOK_PAREN_CLOSE);
return inner;
}
else
{
::std::vector<TypeRef> types;
types.push_back( mv$(inner) );
while( GET_TOK(tok, lex) == TOK_COMMA )
{
if( GET_TOK(tok, lex) == TOK_PAREN_CLOSE )
break;
else
PUTBACK(tok, lex);
types.push_back( Parse_Type(lex) );
}
CHECK_TOK(tok, TOK_PAREN_CLOSE);
return TypeRef(TypeRef::TagTuple(), lex.end_span(mv$(ps)), mv$(types)); }
}
default:
throw ParseError::Unexpected(lex, tok);
}
throw ParseError::BugCheck("Reached end of Parse_Type");
}