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From: Rob Warnock on 27 May 2010 21:05
Pascal J. Bourguignon <pjb(a)informatimago.com> wrote:
+---------------
| Scott Graham <scott.cll(a)h4ck3r.net> writes:
| > ... I had made it harder for myself by attempting to rename
| > the symbol that the 'go' was jumping to. That seems to make it
| > necessary to understand the structure of "everything" to be able to
| > find the go's.
| >
| > If I just walk the top level though, it isn't too complex.
|
| Notice that in the top level macro, you can use macrolet and
| flet/labels to provide operators to the inferior lexical levels as
| deep as needed.
+---------------

Note that this is a fairly common idiom in CL macrology. E.g., the
main macro in the HTML-generating HTOUT & CL-WHO is WITH-HTML-OUTPUT,
which defines a whole bunch of helper macrolets -- HTM, FMT, LFD,
ESC, & STR -- which capture/reference bits of the lexical environment
set up by WITH-HTML-OUTPUT (well, really only the output stream variable,
but it *could* have been more) to provide useful abbreviations within
the body of the main macro.

Similarly, "collecting" macros define macrolets for various collection
operators [see EXT:COLLECT in CMUCL].


-Rob

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

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