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Re: Unmemoization of macros
From: |
Mikael Djurfeldt |
Subject: |
Re: Unmemoization of macros |
Date: |
20 Dec 2000 06:08:37 +0100 |
User-agent: |
Gnus/5.0807 (Gnus v5.8.7) Emacs/20.7 |
[Mikael's obligatory additional note follows here. Also: Note the
dangerous omission of address@hidden in the message header]
Mikael Djurfeldt <address@hidden> writes:
> This motivates why it is OK to modify the simple interpreter model by
> adding that the interpreter *may* be smart and not do the translation
> every time, but promises to do so if the macro has changed.
I almost forgot the most important thing:
What is so great about this simple model that we would like to make
these efforts?
Answer: The macro abstraction works symmetrically to the procedure
abstraction in the sense that just as top-level procedure references
in the body of a definition always refer to the most recently
evaluated definition of that name, the same holds true also for
top-level macro references.
This avoids the thready complexity of this symmetry holding under some
conditions (macro/interpreted code) but not under others
(mmacro/compiled code), and, in this latter case, of the macro uses
having the semantics of a definition which *happened* to exist at some
point in time between the definition of the procedure under
consideration and "now", a complexity which has very bad,
non-intuitive, unpractical consequences during everyday development
work.
- Re: Macro uexpansion, (continued)
- Re: Macro uexpansion, Mikael Djurfeldt, 2000/12/19
- Re: Macro uexpansion, Jim Blandy, 2000/12/19
- Re: Macro uexpansion, Mikael Djurfeldt, 2000/12/19
- Re: Macro uexpansion, Mikael Djurfeldt, 2000/12/20
- Re: Macro uexpansion, Craig Brozefsky, 2000/12/20
- Re: Macro uexpansion, Mikael Djurfeldt, 2000/12/19
- Re: New module system, Jim Blandy, 2000/12/19
- Re: New module system, Mikael Djurfeldt, 2000/12/19
- Re: New module system, Marius Vollmer, 2000/12/19
- Unmemoization of macros, Mikael Djurfeldt, 2000/12/19
- Re: Unmemoization of macros,
Mikael Djurfeldt <=
- Re: Unmemoization of macros, Marius Vollmer, 2000/12/23