parser: Fixes boolean binary operation precedence

The comparators && and || should have precedence over others comparators
(> < >= <= == !=).

Signed-off-by: Carlos Maniero <carlos@maniero.me>

1 files changed, 41 insertions, 7 deletions

diff --git a/src/parser.c b/src/parser.c
index 9167f1e..e3f157f 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -156,7 +156,10 @@ ast_node_t *
 parser_parse_expression(parser_t *parser);
 
 static ast_node_t *
-parser_parse_comparison(parser_t *parser);
+parser_parse_comparison1(parser_t *parser);
+
+static ast_node_t *
+parser_parse_comparison2(parser_t *parser);
 
 static ast_node_t *
 parser_parse_arithmetic1(parser_t *parser);
@@ -169,8 +172,9 @@ parser_parse_factor(parser_t *parser);
 
 /**
  *
- * <expression>  ::= <comparison>
- * <comparison>  ::= <arithmetic1> (('>' | '>=' | '=' | ...) arithmetic1)*
+ * <expression>  ::= <comparison1>
+ * <comparison1> ::= <comparison2> (('>' | '>=' | '=' | ...) comparison2)*
+ * <comparison2> ::= <arithmetic1> (('>' | '>=' | '=' | ...) arithmetic1)*
  * <arithmetic1> ::= <arithmetic2> (('+' | '-') arithmetic2)*
  * <arithmetic2> ::= <factor> (('*' | '/') factor)*
  * <factor>      ::= <integer> | '(' <expression> ')'
@@ -179,11 +183,42 @@ parser_parse_factor(parser_t *parser);
 ast_node_t *
 parser_parse_expression(parser_t *parser)
 {
-  return parser_parse_comparison(parser);
+  return parser_parse_comparison1(parser);
+}
+
+static ast_node_t *
+parser_parse_comparison1(parser_t *parser)
+{
+  ast_node_t *node = parser_parse_comparison2(parser);
+
+  if (node == NULL) {
+    return NULL;
+  }
+
+  token_t token;
+  lexer_peek_next_token(parser->lexer, &token);
+
+  while (token.kind == TOKEN_AND || token.kind == TOKEN_OR) {
+    lexer_drop_next_token(parser->lexer);
+
+    ast_node_t *left = node;
+    ast_node_t *right = parser_parse_comparison2(parser);
+
+    if (right == NULL) {
+      ast_node_destroy(node);
+      return NULL;
+    }
+
+    node = ast_node_new_binary_operation(token_to_binary_operation_kind(&token), left, right, TYPE_BOOL);
+
+    lexer_peek_next_token(parser->lexer, &token);
+  }
+
+  return node;
 }
 
 static ast_node_t *
-parser_parse_comparison(parser_t *parser)
+parser_parse_comparison2(parser_t *parser)
 {
   ast_node_t *node = parser_parse_arithmetic1(parser);
 
@@ -195,8 +230,7 @@ parser_parse_comparison(parser_t *parser)
   lexer_peek_next_token(parser->lexer, &token);
 
   while (token.kind == TOKEN_GT || token.kind == TOKEN_LT || token.kind == TOKEN_GT_EQUAL ||
-         token.kind == TOKEN_LT_EQUAL || token.kind == TOKEN_EQUAL || token.kind == TOKEN_NOT_EQUAL ||
-         token.kind == TOKEN_AND || token.kind == TOKEN_OR) {
+         token.kind == TOKEN_LT_EQUAL || token.kind == TOKEN_EQUAL || token.kind == TOKEN_NOT_EQUAL) {
     lexer_drop_next_token(parser->lexer);
 
     ast_node_t *left = node;