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| author | Kaz Kylheku <kaz@kylheku.com> | 2015-07-11 07:28:47 -0700 |
|---|---|---|
| committer | Kaz Kylheku <kaz@kylheku.com> | 2015-07-11 07:28:47 -0700 |
| commit | f888430a6012947a9aea3624592dff1fc1f18726 (patch) | |
| tree | 3b7af565caea3cd82de0d516c2a8e3b626841b9d /txr.1 | |
| parent | 4ccc4bff6556940a1268d96ec60bb2f599f0fe6d (diff) | |
| download | txr-f888430a6012947a9aea3624592dff1fc1f18726.tar.gz txr-f888430a6012947a9aea3624592dff1fc1f18726.tar.bz2 txr-f888430a6012947a9aea3624592dff1fc1f18726.zip | |
Let's have placelet and placelet*.
* share/txr/stdlib/place.tl (placelet*): New macro.
* lisplib.c (place_set_entries): Add placelet* to list of names.
* txr.1: Updated to document placelet* and fix mistakes.
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 23 |
1 files changed, 20 insertions, 3 deletions
@@ -28679,9 +28679,10 @@ applies inside a form. Of course, lexical operator macros do not shadow symbol macros under any circumstances. -.coNP Operator @ placelet +.coNP Macros @ placelet and @ placelet* .synb .mets (placelet >> ({( sym << place )}*) << body-form *) +.mets (placelet* >> ({( sym << place )}*) << body-form *) .syne .desc The @@ -28710,10 +28711,26 @@ scope of the This means that whenever .meta sym is evaluated, it stands for the value of the storage -location, and whenever a value is apprently stored into +location, and whenever a value is apparently stored into .metn sym , it is actually the storage location which receives it. +The +.code placelet* +variant implements an alternative scoping rule, which allows a later +.meta place +form to refer to a +.meta sym +bound to an earlier +.meta place +form. In other words, a given +.meta sym +binding is visible not only to the +.metn body-form -s +but also to +.meta place +forms which occur later. + Note: certain kinds of places, notably .cblk .meti (force << promise ) @@ -28735,7 +28752,7 @@ performs the syntactic substitution of symbol .code x by form .codn y , -whereever +wherever .code x appears inside .code z |