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parse if maybe expression

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This commit is contained in:
Andrew Kelley
2015-12-26 15:05:27 -07:00
parent 5943f99510
commit 1f8e3871ee
9 changed files with 176 additions and 72 deletions
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71
src/parser.cpp
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@@ -114,8 +114,10 @@ const char *node_type_str(NodeType node_type) {
return "Void";
case NodeTypeBoolLiteral:
return "BoolLiteral";
case NodeTypeIfExpr:
return "IfExpr";
case NodeTypeIfBoolExpr:
return "IfBoolExpr";
case NodeTypeIfVarExpr:
return "IfVarExpr";
case NodeTypeWhileExpr:
return "WhileExpr";
case NodeTypeLabel:
@@ -321,14 +323,27 @@ void ast_print(AstNode *node, int indent) {
case NodeTypeBoolLiteral:
fprintf(stderr, "%s '%s'\n", node_type_str(node->type), node->data.bool_literal ? "true" : "false");
break;
case NodeTypeIfExpr:
case NodeTypeIfBoolExpr:
fprintf(stderr, "%s\n", node_type_str(node->type));
if (node->data.if_expr.condition)
ast_print(node->data.if_expr.condition, indent + 2);
ast_print(node->data.if_expr.then_block, indent + 2);
if (node->data.if_expr.else_node)
ast_print(node->data.if_expr.else_node, indent + 2);
if (node->data.if_bool_expr.condition)
ast_print(node->data.if_bool_expr.condition, indent + 2);
ast_print(node->data.if_bool_expr.then_block, indent + 2);
if (node->data.if_bool_expr.else_node)
ast_print(node->data.if_bool_expr.else_node, indent + 2);
break;
case NodeTypeIfVarExpr:
{
Buf *name_buf = &node->data.if_var_expr.var_decl.symbol;
fprintf(stderr, "%s '%s'\n", node_type_str(node->type), buf_ptr(name_buf));
if (node->data.if_var_expr.var_decl.type)
ast_print(node->data.if_var_expr.var_decl.type, indent + 2);
if (node->data.if_var_expr.var_decl.expr)
ast_print(node->data.if_var_expr.var_decl.expr, indent + 2);
ast_print(node->data.if_var_expr.then_block, indent + 2);
if (node->data.if_var_expr.else_node)
ast_print(node->data.if_var_expr.else_node, indent + 2);
break;
}
case NodeTypeWhileExpr:
fprintf(stderr, "%s\n", node_type_str(node->type));
ast_print(node->data.while_expr.condition, indent + 2);
@@ -1644,7 +1659,9 @@ static AstNode *ast_parse_else_or_else_if(ParseContext *pc, int *token_index, bo
}
/*
IfExpression : token(If) Expression Block option(Else | ElseIf)
IfExpression : IfVarExpression | IfBoolExpression
IfBoolExpression : token(If) option((token) Expression Block option(Else | ElseIf)
IfVarExpression : token(If) (token(Const) | token(Var)) token(Symbol) option(token(Colon) Type) Token(Eq) Expression Block Option(Else | ElseIf)
*/
static AstNode *ast_parse_if_expr(ParseContext *pc, int *token_index, bool mandatory) {
Token *if_tok = &pc->tokens->at(*token_index);
@@ -1657,11 +1674,37 @@ static AstNode *ast_parse_if_expr(ParseContext *pc, int *token_index, bool manda
}
*token_index += 1;
AstNode *node = ast_create_node(pc, NodeTypeIfExpr, if_tok);
node->data.if_expr.condition = ast_parse_expression(pc, token_index, true);
node->data.if_expr.then_block = ast_parse_block(pc, token_index, true);
node->data.if_expr.else_node = ast_parse_else_or_else_if(pc, token_index, false);
return node;
Token *token = &pc->tokens->at(*token_index);
if (token->id == TokenIdKeywordConst || token->id == TokenIdKeywordVar) {
AstNode *node = ast_create_node(pc, NodeTypeIfVarExpr, if_tok);
node->data.if_var_expr.var_decl.is_const = (token->id == TokenIdKeywordConst);
*token_index += 1;
Token *name_token = ast_eat_token(pc, token_index, TokenIdSymbol);
ast_buf_from_token(pc, name_token, &node->data.if_var_expr.var_decl.symbol);
Token *eq_or_colon = &pc->tokens->at(*token_index);
*token_index += 1;
if (eq_or_colon->id == TokenIdMaybeAssign) {
node->data.if_var_expr.var_decl.expr = ast_parse_expression(pc, token_index, true);
} else if (eq_or_colon->id == TokenIdColon) {
node->data.if_var_expr.var_decl.type = ast_parse_type(pc, token_index);
ast_eat_token(pc, token_index, TokenIdMaybeAssign);
node->data.if_var_expr.var_decl.expr = ast_parse_expression(pc, token_index, true);
} else {
ast_invalid_token_error(pc, eq_or_colon);
}
node->data.if_var_expr.then_block = ast_parse_block(pc, token_index, true);
node->data.if_var_expr.else_node = ast_parse_else_or_else_if(pc, token_index, false);
return node;
} else {
AstNode *node = ast_create_node(pc, NodeTypeIfBoolExpr, if_tok);
node->data.if_bool_expr.condition = ast_parse_expression(pc, token_index, true);
node->data.if_bool_expr.then_block = ast_parse_block(pc, token_index, true);
node->data.if_bool_expr.else_node = ast_parse_else_or_else_if(pc, token_index, false);
return node;
}
}
/*