From 9aea99a999997e223307d8559e0ff9fa613839a3 Mon Sep 17 00:00:00 2001 From: Andrew Kelley Date: Thu, 7 Jan 2016 05:29:11 -0700 Subject: implement array slicing syntax closes #52 --- src/parser.cpp | 50 ++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 42 insertions(+), 8 deletions(-) (limited to 'src/parser.cpp') diff --git a/src/parser.cpp b/src/parser.cpp index 1f78424fb1..e8da95bb3d 100644 --- a/src/parser.cpp +++ b/src/parser.cpp @@ -90,6 +90,8 @@ const char *node_type_str(NodeType node_type) { return "FnCallExpr"; case NodeTypeArrayAccessExpr: return "ArrayAccessExpr"; + case NodeTypeSliceExpr: + return "SliceExpr"; case NodeTypeExternBlock: return "ExternBlock"; case NodeTypeDirective: @@ -298,6 +300,14 @@ void ast_print(AstNode *node, int indent) { ast_print(node->data.array_access_expr.array_ref_expr, indent + 2); ast_print(node->data.array_access_expr.subscript, indent + 2); break; + case NodeTypeSliceExpr: + fprintf(stderr, "%s\n", node_type_str(node->type)); + ast_print(node->data.slice_expr.array_ref_expr, indent + 2); + ast_print(node->data.slice_expr.start, indent + 2); + if (node->data.slice_expr.end) { + ast_print(node->data.slice_expr.end, indent + 2); + } + break; case NodeTypeDirective: fprintf(stderr, "%s\n", node_type_str(node->type)); break; @@ -1381,9 +1391,10 @@ static AstNode *ast_parse_primary_expr(ParseContext *pc, int *token_index, bool } /* -SuffixOpExpression : PrimaryExpression option(FnCallExpression | ArrayAccessExpression | FieldAccessExpression) +SuffixOpExpression : PrimaryExpression option(FnCallExpression | ArrayAccessExpression | FieldAccessExpression | SliceExpression) FnCallExpression : token(LParen) list(Expression, token(Comma)) token(RParen) ArrayAccessExpression : token(LBracket) Expression token(RBracket) +SliceExpression : token(LBracket) Expression token(Ellipsis) option(Expression) token(RBracket) option(token(Const)) FieldAccessExpression : token(Dot) token(Symbol) */ static AstNode *ast_parse_suffix_op_expr(ParseContext *pc, int *token_index, bool mandatory) { @@ -1405,15 +1416,38 @@ static AstNode *ast_parse_suffix_op_expr(ParseContext *pc, int *token_index, boo } else if (token->id == TokenIdLBracket) { *token_index += 1; - AstNode *node = ast_create_node(pc, NodeTypeArrayAccessExpr, token); - node->data.array_access_expr.array_ref_expr = primary_expr; - node->data.array_access_expr.subscript = ast_parse_expression(pc, token_index, true); + AstNode *expr_node = ast_parse_expression(pc, token_index, true); - Token *r_bracket = &pc->tokens->at(*token_index); - *token_index += 1; - ast_expect_token(pc, r_bracket, TokenIdRBracket); + Token *ellipsis_or_r_bracket = &pc->tokens->at(*token_index); - primary_expr = node; + if (ellipsis_or_r_bracket->id == TokenIdEllipsis) { + *token_index += 1; + + AstNode *node = ast_create_node(pc, NodeTypeSliceExpr, token); + node->data.slice_expr.array_ref_expr = primary_expr; + node->data.slice_expr.start = expr_node; + node->data.slice_expr.end = ast_parse_expression(pc, token_index, false); + + ast_eat_token(pc, token_index, TokenIdRBracket); + + Token *const_tok = &pc->tokens->at(*token_index); + if (const_tok->id == TokenIdKeywordConst) { + *token_index += 1; + node->data.slice_expr.is_const = true; + } + + primary_expr = node; + } else if (ellipsis_or_r_bracket->id == TokenIdRBracket) { + *token_index += 1; + + AstNode *node = ast_create_node(pc, NodeTypeArrayAccessExpr, token); + node->data.array_access_expr.array_ref_expr = primary_expr; + node->data.array_access_expr.subscript = expr_node; + + primary_expr = node; + } else { + ast_invalid_token_error(pc, token); + } } else if (token->id == TokenIdDot) { *token_index += 1; -- cgit v1.2.3