Hygienic macros (was: do...until wisdom needed...)

[Dave LeBlanc]

Tcl semantics messy? <gasp> May you be a cobol programmer in your next
incarnation!

;-)

FWIW, Tcl is actually based on Lisp - i'm told quite closely once you
get past the syntactical sugar.

Dave LeBlanc

On 18 Apr 2001 06:02:32 -0400, Douglas Alan <nessus at mit.edu> wrote:

>whisper at oz.net (Dave LeBlanc) writes:
>
>> On 17 Apr 2001 20:59:52 -0400, Douglas Alan <nessus at mit.edu> wrote:
>
>> > Lisp has traditionally had "procedural macros".  Procedural macros
>> > in Lisp are a kind of function -- they are implemented in Lisp,
>> > but the return value of the macro, rather than being returned as a
>> > function value, is taken to be a piece of code.
>
>> Sounds so much like Tcl!
>
>Kind of.  Except God is in the details.  Tcl is slow and its semantics
>are messy.  None of this applies to hygienic procedural macros.
>Hygiene keeps the semantics clean, the macros run at compile-time --
>not at run-time, and the code that is being treated as data has
>structure -- it's not just a string.  Also, procedural macros are
>designed to be used sparingly, not for everything.
>
>|>oug