Errors

This document contains the following sections:

1.0 Errors

Errors in Allegro CL are handled by the condition system as described in the ANSI spec. Note too that some errors in Allegro CL are still classified as simple-errors when they should be classified otherwise.

The errorset macro is preserved from earlier versions of Allegro CL although its functionality is completely superceded by the condition system. It is maintained for backward compatibility and its use in newly written code is not recommended.

Here is the condition type hierarchy. Allegro CL has some additional error types defined. They are marked with an *. The ones with links are further described. You can get the condition object associated with an error with the top-level command :error, which, besides printing the error message sets the value of * to the condition object.

  condition
  advance-warning *
  input-edit *
  ics-dependent-classa *
  ics-dependent-classb *
  compiler-note *
  serious-condition
    storage-condition
    error
      type-error
        case-failure *
        simple-type-error
      stream-error
        stream-closed-error *
        end-of-file
        reader-error (also subclass of parse-error)
        socket-error *
        errno-stream-error *
      parse-error
        reader-error (also subclass of stream-error)
      operating-system-signal *
        synchronous-operating-system-signal *
        asynchronous-operating-system-signal *
          interrupt-signal *
      package-error
        package-locked-error *
      file-error