feat(parser): better error messages

example/basic.c

@@ -37,7 +37,21 @@ int main(int argc, char **argv) {
   mrk_parser_open(parser, lexer);
 
   mrk_ast_node *root;
-  assert(mrk_parser_parse(&root, parser) == mrk_err_ok);
+  mrk_err res = mrk_parser_parse(&root, parser);
+
+  switch (res) {
+    case mrk_err_ok:
+      break;
+    case mrk_err_invalid_md: {
+      const char *err_msg = mrk_parser_err_msg(parser);
+      printf("%s\n", err_msg);
+
+      return 2;
+     }
+    default:
+      printf("mrk error %i\n", res);
+      return 3;
+  }
 
   char *html;
   assert(mrk_ast_to_html(&html, buf, root) == mrk_err_ok);

include/mrk/lexer.h

@@ -44,6 +44,8 @@ typedef enum mrk_token_type {
   mrk_token_type_list_item_unchecked,
 } mrk_token_type;
 
+extern const char *mrk_token_type_names[];
+
 typedef struct mrk_token {
   mrk_token_type type;
   size_t start;

src/lexer/consts.c

@@ -0,0 +1,29 @@
+#include "mrk/lexer.h"
+
+const char *mrk_token_type_names[] = {
+    "",
+    "backtick",
+    "triple backtick",
+    "underscore",
+    "double underscore",
+    "star",
+    "double star",
+    "newline",
+    "blank line",
+    "line break",
+    "right angle brackets",
+    "left bracket",
+    "right bracket",
+    "left parenthesis",
+    "right parenthesis",
+    "bang",
+    "backslash",
+    "text",
+    "header start",
+    "horizontal rule",
+    "indent",
+    "unordered list item",
+    "ordered list item",
+    "checked box",
+    "unchecked box",
+};

src/parser/err.c

@@ -15,21 +15,27 @@ const char *mrk_parser_err_msg(mrk_parser *parser) {
     parser->error.buf[0] = '\0';
     break;
   case mrk_parser_err_unexpected_token:
-    sprintf(parser->error.buf, "%lu:%lu: unexpected token type %i",
+    sprintf(parser->error.buf, "%lu:%lu: unexpected token type '%s' (%i)",
-            parser->error.token.start_line,
+            parser->error.token.start_line + 1,
-            parser->error.token.start_line_index, parser->error.token.type);
+            parser->error.token.start_line_index + 1,
+            mrk_token_type_names[parser->error.token.type],
+            parser->error.token.type);
     break;
   case mrk_parser_err_unexpected_eat:
-    sprintf(parser->error.buf,
+    sprintf(
-            "%lu:%lu: unexpected token, expected type %i but got %i",
+        parser->error.buf,
-            parser->error.token.start_line,
+        "%lu:%lu: unexpected token, expected type '%s' (%i) but got '%s' (%i)",
-            parser->error.token.start_line_index,
+        parser->error.token.start_line + 1,
-            parser->error.expected_token_type, parser->error.token.type);
+        parser->error.token.start_line_index + 1,
+        mrk_token_type_names[parser->error.expected_token_type],
+        parser->error.expected_token_type,
+        mrk_token_type_names[parser->error.token.type],
+        parser->error.token.type);
     break;
   case mrk_parser_unclosed_brackets:
     sprintf(parser->error.buf, "%lu:%lu: unclosed bracket",
-            parser->error.token.start_line,
+            parser->error.token.start_line + 1,
-            parser->error.token.start_line_index);
+            parser->error.token.start_line_index + 1);
     break;
   case mrk_parser_unexpected_path:
     return unexpected_path_msg;