From ea9b427363abfa80eb12d0cdf39cfc48f41afc34 Mon Sep 17 00:00:00 2001
From: tovjemam <gitea@deadfish.cz>
Date: Sun, 13 Oct 2024 21:42:01 +0200
Subject: [PATCH] fix unary precedence

---
 parser.c | 82 +++++++++++++++++++++++++++++---------------------------
 1 file changed, 42 insertions(+), 40 deletions(-)

diff --git a/parser.c b/parser.c
index 399b700..6855ba4 100644
--- a/parser.c
+++ b/parser.c
@@ -28,14 +28,14 @@ static void error_expected_one_of(struct lexer *lex, const int expected[], enum
         "lexer error",
         "constant",
         "+",
-        "-",
-        "*",
-        "/",
-        "^",
-        "x",
-        "function name",
-        "(",
-        ")"
+            "-",
+            "*",
+            "/",
+            "^",
+            "x",
+            "function name",
+            "(",
+            ")"
     };
 
     int separate = 0;
@@ -56,16 +56,16 @@ static void error_expected_one_of(struct lexer *lex, const int expected[], enum
     lex_print_position(lex);
 }
 
-static void error_expected_single(struct lexer *lex, enum token_type expected, enum token_type got) {
+static void error_expected_single(struct lexer* lex, enum token_type expected, enum token_type got) {
     static int expected_arr[] = { -1, -1 };
     expected_arr[0] = expected;
     error_expected_one_of(lex, expected_arr, got);
 }
 
-struct expr_node *parse_subexpression(struct lexer *lex);
+struct expr_node* parse_subexpression(struct lexer* lex);
 
-static struct expr_node *parse_bracketed(struct lexer* lex) {
-    struct expr_node *node;
+static struct expr_node* parse_bracketed(struct lexer* lex) {
+    struct expr_node* node;
 
     if (!accept(lex, TOK_LEFT_PAREN)) {
         error_expected_single(lex, TOK_LEFT_PAREN, lex_token(lex)->type);
@@ -84,9 +84,9 @@ static struct expr_node *parse_bracketed(struct lexer* lex) {
     return node;
 }
 
-static struct expr_node *parse_base(struct lexer *lex) {
-    struct expr_node *inner;
-    
+static struct expr_node* parse_base(struct lexer* lex) {
+    struct expr_node* inner;
+
     if (token_is(lex, TOK_NUMBER)) {
         double val = token_num(lex);
         lex_next(lex);
@@ -119,32 +119,15 @@ static struct expr_node *parse_base(struct lexer *lex) {
     return NULL;
 }
 
-static struct expr_node* parse_unary(struct lexer *lex) {
-    if (accept(lex, TOK_MINUS)) {
-        struct expr_node *node, *inner;
-        
-        if (!(inner = parse_base(lex)))
-            return NULL;
+static struct expr_node* parse_unary(struct lexer* lex);
 
-        if (!(node = node_create_neg(inner))) {
-            node_free(inner);
-            return NULL;
-        }
+static struct expr_node* parse_factor(struct lexer* lex) {
+    struct expr_node* node, * new_node, * inner;
 
-        return node;
-    }
-
-    accept(lex, TOK_PLUS);
-    return parse_base(lex);
-}
-
-static struct expr_node *parse_factor(struct lexer *lex) {
-    struct expr_node *node, *new_node, *inner;
-
-    if (!(node = parse_unary(lex)))
+    if (!(node = parse_base(lex)))
         return NULL;
 
-    while (accept(lex, TOK_POWER)) {
+    if (accept(lex, TOK_POWER)) {
         if (!(inner = parse_unary(lex))) {
             node_free(node);
             return NULL;
@@ -156,16 +139,35 @@ static struct expr_node *parse_factor(struct lexer *lex) {
             return NULL;
         }
 
-        node = new_node;
+        return new_node;
     }
 
     return node;
 }
 
+static struct expr_node* parse_unary(struct lexer *lex) {
+    if (accept(lex, TOK_MINUS)) {
+        struct expr_node *node, *inner;
+        
+        if (!(inner = parse_factor(lex)))
+            return NULL;
+
+        if (!(node = node_create_neg(inner))) {
+            node_free(inner);
+            return NULL;
+        }
+
+        return node;
+    }
+
+    accept(lex, TOK_PLUS);
+    return parse_factor(lex);
+}
+
 static struct expr_node *parse_term(struct lexer *lex) {
     struct expr_node *node, *new_node, *inner;
 
-    if (!(node = parse_factor(lex)))
+    if (!(node = parse_unary(lex)))
         return NULL;
 
     while (1) {
@@ -178,7 +180,7 @@ static struct expr_node *parse_term(struct lexer *lex) {
         else
             break;
 
-        if (!(inner = parse_factor(lex))) {
+        if (!(inner = parse_unary(lex))) {
             node_free(node);
             return NULL;
         }