fluffos/docs/apply/master/parser_error_message.md

title
master / parser_error_message

parser_error_message

NAME

parser_error_message - generate custom parser error messages

SYNOPSIS

string parser_error_message(int error_type, object ob, ...) ;

DESCRIPTION

This apply is called by the parser package when a parsing error occurs,
allowing the mudlib to provide custom error messages for parse_sentence()
failures.

**Arguments:**
- `error_type`: The type of parsing error that occurred
- `ob`: The object that caused the error (may be 0)
- Additional arguments depend on the error type

**Error Types and Arguments:**

- `ERR_IS_NOT` / `ERR_NOT_LIVING` / `ERR_NOT_ACCESSIBLE` (4 arguments):
  - `string noun`: The noun that caused the error
  - `int is_plural`: 1 if plural, 0 if singular

- `ERR_AMBIG` (3 arguments):
  - `object *objects`: Array of ambiguous objects

- `ERR_ORDINAL` (3 arguments):
  - `int ordinal`: The problematic ordinal number

- `ERR_THERE_IS_NO` (3 arguments):
  - `string phrase`: The problematic word sequence

- `ERR_ALLOCATED` (3 arguments):
  - `string message`: An allocated error string

- `ERR_BAD_MULTIPLE` (2 arguments):
  - (no additional arguments)

- `ERR_MANY_PATHS` (5 arguments):
  - (additional path-related data)

**Return Value:**
- Return a string containing the error message to show to the user
- Return 0 to use default error handling

EXAMPLE

```c
string parser_error_message(int type, object ob, mixed arg) {
    switch(type) {
        case ERR_NOT_LIVING:
            return "The " + arg + " is not alive.";
        case ERR_AMBIG:
            return "Which " + file_name(arg[0]) + " do you mean?";
        case ERR_THERE_IS_NO:
            return "I don't see any '" + arg + "' here.";
        default:
            return "I don't understand that.";
    }
}
```

SEE ALSO

parse_sentence(3), parse_init(3)

NOTE

This apply requires the parser package to be enabled. Error type constants
should be defined in your mudlib's include files based on the parser
package implementation.