30. error

Synopsis

Generate an error condition

Usage

error (String_Type msg

Description

The error function generates a S-lang error condition causing the interpreter to start unwinding to top-level. It takes a single string parameter which is displayed on the stderr output device. The error condition may be cleared via an ERROR_BLOCK with the _clear_error function. Consult A Guide to the S-Lang Language for more information.

Example

    define add_txt_extension (file)
    {
       if (typeof (file) != String_Type)
         error ("add_extension: parameter must be a string");
       file += ".txt";
       return file;
    }

See Also

verror, _clear_error, message