Ron Garret  <rNOSPAMon@flownet.com> wrote:
+---------------
|  Ron Garret <rNOSPAMon@flownet.com> wrote:
| > I mostly use CLisp for compatibility tests
| 
| I note with a certain wry amusement that (ignore-errors (function 
| ignore-errors)) returns NIL in CLisp even in compiled code.
+---------------

You need to look at the *second* value, too, which per the CLHS
entry for IGNORE-ERRORS contains the condition resulting from the
error [if any]. E.g., in CLISP:

    [1]> (ignore-errors (function ignore-errors))
    NIL ;
    #<SYSTEM::SIMPLE-UNDEFINED-FUNCTION #x203FB779>
    [2]> 

or CMUCL:

    cmu> (ignore-errors (function ignore-errors))

    ; In: IGNORE-ERRORS #'IGNORE-ERRORS

    ;   #'IGNORE-ERRORS
    ; Error: Found macro name IGNORE-ERRORS as the argument to FUNCTION.
    ; 
    NIL
    #<KERNEL:SIMPLE-PROGRAM-ERROR {589054B5}>
    cmu> 

Though compiled CLISP's behavior is a bit "different":

    [3]> (defun foo () (ignore-errors (function ignore-errors)))
    FOO
    [4]> (compile *)
    FOO ;
    NIL ;
    NIL
    [5]> (foo)
    #<MACRO #<COMPILED-CLOSURE IGNORE-ERRORS>>
    [6]> 

CMUCL, while complaining mightily during the COMPILE, still returns
two reasonable values in the compiled case:

    cmu> (defun foo () (ignore-errors (function ignore-errors)))

    FOO
    cmu> (compile *)

    ; In: LAMBDA NIL
    ;   #'IGNORE-ERRORS
    ; Error: Found macro name IGNORE-ERRORS as the argument to FUNCTION.
    ; 
    ; Compiling LAMBDA NIL: 
    ; Compiling Top-Level Form: 

    ; Compilation unit finished.
    ;   1 error

    FOO
    T
    T
    cmu> (foo)

    NIL
    #<KERNEL:SIMPLE-PROGRAM-ERROR {58947CA5}>
    cmu> 


-Rob

-----
Rob Warnock			<rpw3@rpw3.org>
627 26th Avenue			<URL:http://rpw3.org/>
San Mateo, CA 94403		(650)572-2607