MONDAY  JULY 29,1974	FQ+3D.1H.24M.28S.   LISP 873  - GLS -


THIS LISP RECENT IS SHORT, BUT ITEM [2] IS OF GREAT IMPORTANCE.
THE PREVIOUS LISP RECENT APPEARS AT THE END OF THIS ONE SINCE
IT HASN'T BEEN AROUND FOR VERY LONG.

BRIEF SYNOPSIS:

[1] *RSET-TRAP FUNCTION IS ALWAYS RUN AND MUST CHECK *RSET ITSELF
[2] (CAR NIL) AND (CDR NIL) ARE ALWAYS NIL
[3] DUMPARRAYS/LOADARRAYS NOW KNOW ABOUT FIXNUM AND FLONUM ARRAYS
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[1] THE *RSET-TRAP USER INTERRUPT IS ALWAYS RUN WHEN AN
    UNCORRECTABLE ERROR IS ABOUT TO POP BACK TO TOP LEVEL
    OR TO AN ERRSET.  IT IS UP TO THE *RSET-TRAP FUNCTION
    TO CHECK THE *RSET SWITCH FOR ITSELF (THE SYSTEM-SUPPLIED
    *RSET-TRAP FUNCTION INDEED DOES THIS).

[2] FOR COMPATIBILITY WITH INTERLISP (FOO), THE CAR AND CDR
    OF NIL ARE ALWAYS BUT ALWAYS NIL. NIL STILL HAS A
    PROPERTY LIST, AND GET AND PUTPROP STILL WORK ON IT,
    BUT NIL'S PROPERTY LIST IS NOT ITS CDR (CROCK, CROCK).
    THE CLAIM IS THAT ONE CAN WRITE CODE SUCH AS
	(CADDR X)
    INSTEAD OF THE MORE TIME- AND SPACE-CONSUMING
	(AND (CDR X) (CDDR X) (CADDR X))
    AND SO ON. SEND COMPLAINTS TO GLS, BUT I DOUBT IT WILL
    DO YOU ANY GOOD.

[3] DUMPARRAYS AND LOADARRAYS WILL NOW DO THE CORRECT THING
    WITH FIXNUM AND FLONUM ARRAYS.  OLD DUMPARRAYS FILES ARE
    STILL GOOD - THE HACK IS UPWARD COMPATIBLE.