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bug#22101: Emacs-25: inaccuracy in documentation of `mapconcat' in .../l
From: |
Alan Mackenzie |
Subject: |
bug#22101: Emacs-25: inaccuracy in documentation of `mapconcat' in .../lispref/functions.texi |
Date: |
Sun, 6 Dec 2015 10:26:22 +0000 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
Hello, Emacs.
In the elisp manual, mapconcat is described thusly:
`mapconcat' applies FUNCTION to each element of SEQUENCE: the
results, which must be strings, are concatenated. Between each
^^^^^^^^^^^^^^^^^^^^^
pair of result strings, `mapconcat' inserts the string SEPARATOR.
^^^^^^^^^^
Usually SEPARATOR contains a space or comma or other suitable
punctuation.
The results returned by FUNCTION need not be strings; they may be of any
sequence type acceptable to `concat'. The same applies to SEPARATOR.
Either the code or the documentation is wrong. I strongly believe it's
the documentation.
Here's a patch to fix it. I will apply this patch to the emacs-25 branch
soon, if I don't hear any objections.
diff --git a/doc/lispref/functions.texi b/doc/lispref/functions.texi
index 8835667..1b949f2 100644
--- a/doc/lispref/functions.texi
+++ b/doc/lispref/functions.texi
@@ -861,13 +861,15 @@ Mapping Functions
@defun mapconcat function sequence separator
@code{mapconcat} applies @var{function} to each element of
-@var{sequence}: the results, which must be strings, are concatenated.
-Between each pair of result strings, @code{mapconcat} inserts the string
+@var{sequence}: the results, which must be sequences, are
+concatenated. These result sequences are usually strings, but may
+also be lists of numbers or vectors of numbers. Between each pair of
+result sequences, @code{mapconcat} inserts the sequence
@var{separator}. Usually @var{separator} contains a space or comma or
other suitable punctuation.
The argument @var{function} must be a function that can take one
-argument and return a string. The argument @var{sequence} can be any
+argument and return a sequence. The argument @var{sequence} can be any
kind of sequence except a char-table; that is, a list, a vector, a
bool-vector, or a string.
--
Alan Mackenzie (Nuremberg, Germany).
- bug#22101: Emacs-25: inaccuracy in documentation of `mapconcat' in .../lispref/functions.texi,
Alan Mackenzie <=