Add token_names API - close #17

spec/test_error_positions.c

@@ -35,5 +35,8 @@ int main()
     assert(p_position(&context).row == 5);
     assert(p_position(&context).col == 4);
 
+    assert(strcmp(p_token_names[TOKEN_a], "a") == 0);
+    assert(strcmp(p_token_names[TOKEN_num], "num") == 0);
+
     return 0;
 }

spec/test_error_positions.d

@@ -34,4 +34,7 @@ unittest
     p_context_init(&context, input);
     assert(p_parse(&context) == P_DECODE_ERROR);
     assert(p_position(&context) == p_position_t(5, 4));
+
+    assert(p_token_names[TOKEN_a] == "a");
+    assert(p_token_names[TOKEN_num] == "num");
 }