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Issue: DISASSEMBLE-SIDE-EFFECT (version 4)
- To: cl-cleanup%sail.stanford.edu@multimax
- Subject: Issue: DISASSEMBLE-SIDE-EFFECT (version 4)
- From: Dan L. Pierson <pierson%mist@multimax.ARPA>
- Date: Fri, 10 Jun 88 11:45:50 EDT
Walter asked for this correction and I can't remember whether this was
formally passed last meeting or not. If it was, then I'd prefer not
to disturb it.
References: DISASSEMBLE (p. 439), COMPILE (p. 439)
Edit history: Version 2 by Pierson 12/30/87
Version 3 by Pierson 1/21/88
Version 4 by Pierson 6/10/88 correct VAX Lisp practice
Status: Ready For Release?
The definition of DISASSEMBLE says that "if the relevant function is
not a compiled function, it is first compiled.". The definition of
COMPILE says that "If name is a non-nil symbol, then the
compiled-function is installed as the global function definition of
the symbol...". Several implementations have taken this to mean that
if DISASSEMBLE is passed a symbol which has an uncompiled function
definition, then it has the side-effect of (COMPILE 'symbol).
Clarify that when DISASSEMBLE compiles a function, it will never
install the newly compiled function.
(DEFUN F (A) (1+ A))
(EQ (SYMBOL-FUNCTION 'F)
(PROGN (DISASSEMBLE 'F)
This code will return T if this proposal is adopted. Some current
implementations will return T, some will return NIL.
Several current implementations of DISASSEMBLE have surprising side
effects, especially for new users.
Allegro CL installs the compiled definition. Lucid, Symbolics, Xerox,
VAX Lisp, and KCL don't install it.
Cost to Implementors:
Some implementations will have to make a simple change.
Cost to Users:
Very little. DISASSEMBLE is really part of the environment and is
probably not called by much, if any user code.
Cost of non-Adoption:
DISASSEMBLE will continue to surprise less experienced users.
DISASSEMBLE will become the predictable debugging function it was
meant to be.
Some who worried that DISASSEMBLE was supposed to install the compiled
function may find that the language has become a little cleaner.
DISASSEMBLE is an environment feature; some question has been raised
as to the place and force of environment features in the standard.
However, this proposal stands if DISASSEMBLE is part of the standard