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| author | Kaz Kylheku <kaz@kylheku.com> | 2019-06-25 07:28:47 -0700 |
|---|---|---|
| committer | Kaz Kylheku <kaz@kylheku.com> | 2019-06-25 07:28:47 -0700 |
| commit | 9bab9ac8f5634964fe106caace56315b33c06f36 (patch) | |
| tree | d808a2f7c2f2b26de291b84f73e69a8031df0269 | |
| parent | 90bda5c939db3a65a7c9dc1347855b4a1def1f0a (diff) | |
| download | txr-9bab9ac8f5634964fe106caace56315b33c06f36.tar.gz txr-9bab9ac8f5634964fe106caace56315b33c06f36.tar.bz2 txr-9bab9ac8f5634964fe106caace56315b33c06f36.zip | |
doc: clarify nullify.
* txr.1: Clarify that nullify also just returns its argument
if it is not a sequence at all. Clarify that nullify works
on objects via the nullify method only.
| -rw-r--r-- | txr.1 | 31 |
1 files changed, 26 insertions, 5 deletions
@@ -31833,7 +31833,7 @@ by using .coNP Function @ nullify .synb -.mets (nullify << sequence ) +.mets (nullify << obj ) .syne .desc The @@ -31841,11 +31841,32 @@ The function returns .code nil if -.meta sequence +.meta obj is an empty sequence. -Otherwise it returns -.meta sequence -itself. +Otherwise, if +.meta obj +is not an empty sequence, or isn't a sequence, then +.meta obj +itself is returned. + +If +.meta obj +is a structure, then +.meta obj +is returned if it doesn't support the +.code nullify +method, even if it has other methods such as +.code length +by which it could be inferred that it represents an empty sequence. + +If +.meta obj +has a +.code nullify +method, then the +.code nullify +function invokes that method and returns whatever value +that method returns. Note: the .code nullify |