1 files changed, 92 insertions, 70 deletions

diff --git a/src/parser.cpp b/src/parser.cpp
index c7675ad67d..2bd94033cc 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -705,7 +705,7 @@ static AstNode *ast_parse_comptime_expr(ParseContext *pc, size_t *token_index, b
 }
 
 /*
-PrimaryExpression = Integer | Float | String | CharLiteral | KeywordLiteral | GroupedExpression | BlockExpression(BlockOrExpression) | Symbol | ("@" Symbol FnCallExpression) | ArrayType | FnProto | AsmExpression | ContainerDecl | ("continue" option(":" Symbol)) | ErrorSetDecl
+PrimaryExpression = Integer | Float | String | CharLiteral | KeywordLiteral | GroupedExpression | BlockExpression(BlockOrExpression) | Symbol | ("@" Symbol FnCallExpression) | ArrayType | FnProto | AsmExpression | ContainerDecl | ("continue" option(":" Symbol)) | ErrorSetDecl | PromiseType
 KeywordLiteral = "true" | "false" | "null" | "undefined" | "error" | "this" | "unreachable" | "suspend"
 ErrorSetDecl = "error" "{" list(Symbol, ",") "}"
 */
@@ -774,6 +774,15 @@ static AstNode *ast_parse_primary_expr(ParseContext *pc, size_t *token_index, bo
         AstNode *node = ast_create_node(pc, NodeTypeSuspend, token);
         *token_index += 1;
         return node;
+    } else if (token->id == TokenIdKeywordPromise) {
+        AstNode *node = ast_create_node(pc, NodeTypePromiseType, token);
+        *token_index += 1;
+        Token *arrow_tok = &pc->tokens->at(*token_index);
+        if (arrow_tok->id == TokenIdArrow) {
+            *token_index += 1;
+            node->data.promise_type.payload_type = ast_parse_type_expr(pc, token_index, true);
+        }
+        return node;
     } else if (token->id == TokenIdKeywordError) {
         Token *next_token = &pc->tokens->at(*token_index + 1);
         if (next_token->id == TokenIdLBrace) {
@@ -955,8 +964,68 @@ static AstNode *ast_parse_curly_suffix_expr(ParseContext *pc, size_t *token_inde
     }
 }
 
+static AstNode *ast_parse_fn_proto_partial(ParseContext *pc, size_t *token_index, Token *fn_token,
+        AstNode *async_allocator_type_node, CallingConvention cc, bool is_extern, VisibMod visib_mod)
+{
+    AstNode *node = ast_create_node(pc, NodeTypeFnProto, fn_token);
+    node->data.fn_proto.visib_mod = visib_mod;
+    node->data.fn_proto.cc = cc;
+    node->data.fn_proto.is_extern = is_extern;
+    node->data.fn_proto.async_allocator_type = async_allocator_type_node;
+
+    Token *fn_name = &pc->tokens->at(*token_index);
+
+    if (fn_name->id == TokenIdSymbol) {
+        *token_index += 1;
+        node->data.fn_proto.name = token_buf(fn_name);
+    } else {
+        node->data.fn_proto.name = nullptr;
+    }
+
+    ast_parse_param_decl_list(pc, token_index, &node->data.fn_proto.params, &node->data.fn_proto.is_var_args);
+
+    Token *next_token = &pc->tokens->at(*token_index);
+    if (next_token->id == TokenIdKeywordAlign) {
+        *token_index += 1;
+        ast_eat_token(pc, token_index, TokenIdLParen);
+
+        node->data.fn_proto.align_expr = ast_parse_expression(pc, token_index, true);
+        ast_eat_token(pc, token_index, TokenIdRParen);
+        next_token = &pc->tokens->at(*token_index);
+    }
+    if (next_token->id == TokenIdKeywordSection) {
+        *token_index += 1;
+        ast_eat_token(pc, token_index, TokenIdLParen);
+
+        node->data.fn_proto.section_expr = ast_parse_expression(pc, token_index, true);
+        ast_eat_token(pc, token_index, TokenIdRParen);
+        next_token = &pc->tokens->at(*token_index);
+    }
+    if (next_token->id == TokenIdKeywordVar) {
+        node->data.fn_proto.return_var_token = next_token;
+        *token_index += 1;
+        next_token = &pc->tokens->at(*token_index);
+    } else {
+        if (next_token->id == TokenIdKeywordError) {
+            Token *maybe_lbrace_tok = &pc->tokens->at(*token_index + 1);
+            if (maybe_lbrace_tok->id == TokenIdLBrace) {
+                *token_index += 1;
+                node->data.fn_proto.return_type = ast_create_node(pc, NodeTypeErrorType, next_token);
+                return node;
+            }
+        } else if (next_token->id == TokenIdBang) {
+            *token_index += 1;
+            node->data.fn_proto.auto_err_set = true;
+            next_token = &pc->tokens->at(*token_index);
+        }
+        node->data.fn_proto.return_type = ast_parse_type_expr(pc, token_index, true);
+    }
+
+    return node;
+}
+
 /*
-SuffixOpExpression = ("async" option("(" Expression ")") PrimaryExpression FnCallExpression) | PrimaryExpression option(FnCallExpression | ArrayAccessExpression | FieldAccessExpression | SliceExpression)
+SuffixOpExpression = ("async" option("<" SuffixOpExpression ">") SuffixOpExpression FnCallExpression) | PrimaryExpression option(FnCallExpression | ArrayAccessExpression | FieldAccessExpression | SliceExpression)
 FnCallExpression : token(LParen) list(Expression, token(Comma)) token(RParen)
 ArrayAccessExpression : token(LBracket) Expression token(RBracket)
 SliceExpression = "[" Expression ".." option(Expression) "]"
@@ -972,19 +1041,25 @@ static AstNode *ast_parse_suffix_op_expr(ParseContext *pc, size_t *token_index,
 
         AstNode *allocator_expr_node = nullptr;
         Token *async_lparen_tok = &pc->tokens->at(*token_index);
-        if (async_lparen_tok->id == TokenIdLParen) {
+        if (async_lparen_tok->id == TokenIdCmpLessThan) {
             *token_index += 1;
-            allocator_expr_node = ast_parse_expression(pc, token_index, true);
-            ast_eat_token(pc, token_index, TokenIdRParen);
+            allocator_expr_node = ast_parse_prefix_op_expr(pc, token_index, true);
+            ast_eat_token(pc, token_index, TokenIdCmpGreaterThan);
         }
 
-        AstNode *fn_ref_expr_node = ast_parse_primary_expr(pc, token_index, true);
-        Token *lparen_tok = ast_eat_token(pc, token_index, TokenIdLParen);
-        AstNode *node = ast_create_node(pc, NodeTypeFnCallExpr, lparen_tok);
+        Token *fncall_token = &pc->tokens->at(*token_index);
+        if (fncall_token->id == TokenIdKeywordFn) {
+            *token_index += 1;
+            return ast_parse_fn_proto_partial(pc, token_index, fncall_token, allocator_expr_node, CallingConventionAsync,
+                    false, VisibModPrivate);
+        }
+        AstNode *node = ast_parse_suffix_op_expr(pc, token_index, true);
+        if (node->type != NodeTypeFnCallExpr) {
+            ast_error(pc, fncall_token, "expected function call, found '%s'", token_name(fncall_token->id));
+        }
         node->data.fn_call_expr.is_async = true;
         node->data.fn_call_expr.async_allocator = allocator_expr_node;
-        node->data.fn_call_expr.fn_ref_expr = fn_ref_expr_node;
-        ast_parse_fn_call_param_list(pc, token_index, &node->data.fn_call_expr.params);
+        assert(node->data.fn_call_expr.fn_ref_expr != nullptr);
 
         primary_expr = node;
     } else {
@@ -2433,9 +2508,10 @@ static AstNode *ast_parse_fn_proto(ParseContext *pc, size_t *token_index, bool m
     } else if (first_token->id == TokenIdKeywordAsync) {
         *token_index += 1;
         Token *next_token = &pc->tokens->at(*token_index);
-        if (next_token->id == TokenIdLParen) {
+        if (next_token->id == TokenIdCmpLessThan) {
+            *token_index += 1;
             async_allocator_type_node = ast_parse_type_expr(pc, token_index, true);
-            ast_eat_token(pc, token_index, TokenIdRParen);
+            ast_eat_token(pc, token_index, TokenIdCmpGreaterThan);
         }
         fn_token = ast_eat_token(pc, token_index, TokenIdKeywordFn);
         cc = CallingConventionAsync;
@@ -2469,61 +2545,7 @@ static AstNode *ast_parse_fn_proto(ParseContext *pc, size_t *token_index, bool m
         return nullptr;
     }
 
-    AstNode *node = ast_create_node(pc, NodeTypeFnProto, fn_token);
-    node->data.fn_proto.visib_mod = visib_mod;
-    node->data.fn_proto.cc = cc;
-    node->data.fn_proto.is_extern = is_extern;
-    node->data.fn_proto.async_allocator_type = async_allocator_type_node;
-
-    Token *fn_name = &pc->tokens->at(*token_index);
-
-    if (fn_name->id == TokenIdSymbol) {
-        *token_index += 1;
-        node->data.fn_proto.name = token_buf(fn_name);
-    } else {
-        node->data.fn_proto.name = nullptr;
-    }
-
-    ast_parse_param_decl_list(pc, token_index, &node->data.fn_proto.params, &node->data.fn_proto.is_var_args);
-
-    Token *next_token = &pc->tokens->at(*token_index);
-    if (next_token->id == TokenIdKeywordAlign) {
-        *token_index += 1;
-        ast_eat_token(pc, token_index, TokenIdLParen);
-
-        node->data.fn_proto.align_expr = ast_parse_expression(pc, token_index, true);
-        ast_eat_token(pc, token_index, TokenIdRParen);
-        next_token = &pc->tokens->at(*token_index);
-    }
-    if (next_token->id == TokenIdKeywordSection) {
-        *token_index += 1;
-        ast_eat_token(pc, token_index, TokenIdLParen);
-
-        node->data.fn_proto.section_expr = ast_parse_expression(pc, token_index, true);
-        ast_eat_token(pc, token_index, TokenIdRParen);
-        next_token = &pc->tokens->at(*token_index);
-    }
-    if (next_token->id == TokenIdKeywordVar) {
-        node->data.fn_proto.return_var_token = next_token;
-        *token_index += 1;
-        next_token = &pc->tokens->at(*token_index);
-    } else {
-        if (next_token->id == TokenIdKeywordError) {
-            Token *maybe_lbrace_tok = &pc->tokens->at(*token_index + 1);
-            if (maybe_lbrace_tok->id == TokenIdLBrace) {
-                *token_index += 1;
-                node->data.fn_proto.return_type = ast_create_node(pc, NodeTypeErrorType, next_token);
-                return node;
-            }
-        } else if (next_token->id == TokenIdBang) {
-            *token_index += 1;
-            node->data.fn_proto.auto_err_set = true;
-            next_token = &pc->tokens->at(*token_index);
-        }
-        node->data.fn_proto.return_type = ast_parse_type_expr(pc, token_index, true);
-    }
-
-    return node;
+    return ast_parse_fn_proto_partial(pc, token_index, fn_token, async_allocator_type_node, cc, is_extern, visib_mod);
 }
 
 /*
@@ -2901,9 +2923,6 @@ void ast_visit_node_children(AstNode *node, void (*visit)(AstNode **, void *cont
             visit_field(&node->data.fn_def.fn_proto, visit, context);
             visit_field(&node->data.fn_def.body, visit, context);
             break;
-        case NodeTypeFnDecl:
-            visit_field(&node->data.fn_decl.fn_proto, visit, context);
-            break;
         case NodeTypeParamDecl:
             visit_field(&node->data.param_decl.type, visit, context);
             break;
@@ -3068,6 +3087,9 @@ void ast_visit_node_children(AstNode *node, void (*visit)(AstNode **, void *cont
             visit_field(&node->data.array_type.child_type, visit, context);
             visit_field(&node->data.array_type.align_expr, visit, context);
             break;
+        case NodeTypePromiseType:
+            visit_field(&node->data.promise_type.payload_type, visit, context);
+            break;
         case NodeTypeErrorType:
             // none
             break;