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| author | Kaz Kylheku <kaz@kylheku.com> | 2021-10-26 07:46:17 -0700 |
|---|---|---|
| committer | Kaz Kylheku <kaz@kylheku.com> | 2021-10-26 07:46:17 -0700 |
| commit | f32a5ba6ac37703987772560b57aa0dcace0c598 (patch) | |
| tree | d960eca68c0793c1443f62d4cd7b49d6a9cee164 /stdlib | |
| parent | 30638a91a2c47acd08cf67735eac31e5adcf4eba (diff) | |
| download | txr-f32a5ba6ac37703987772560b57aa0dcace0c598.tar.gz txr-f32a5ba6ac37703987772560b57aa0dcace0c598.tar.bz2 txr-f32a5ba6ac37703987772560b57aa0dcace0c598.zip | |
ifa: take advantage of read-once.
* stdlib/ifa.tl (ifa): When the form bound to the it
anaphoric variable is a place, such that we use placelet,
wrap the place in (read-once ...) so that multiple
evaluations of it don't cause multiple accesses of the
place.
* txr.1: Documented.
Diffstat (limited to 'stdlib')
| -rw-r--r-- | stdlib/ifa.tl | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/stdlib/ifa.tl b/stdlib/ifa.tl index eaab6f3a..317ef9e7 100644 --- a/stdlib/ifa.tl +++ b/stdlib/ifa.tl @@ -54,7 +54,7 @@ (let* ((btemps (mapcar (ret (gensym)) before-it)) (atemps (mapcar (ret (gensym)) after-it))) ^(let (,*(zip btemps before-it)) - (placelet ((it ,it-form)) + (placelet ((it (read-once ,it-form))) (let (,*(zip atemps after-it)) (if (,sym ,*(if (eq 'dwim sym) ^(,(second test))) ,*btemps it ,*atemps) |