[PATCH] Doc/Zsh/compsys.yo: clarify _alternative's action syntax

[Arseny Maslennikov <ar@xxxxxxxxx>]

---

Recently, while writing a completion function that uses _alternative to
generate several groups of matches and description strings with
_describe, I decided to look closely at _alternative's source.
It turned out that, contrary to the documentation, I do not have to
escape the separator between a match and its description in the embedded
array representation, unlike the analogous form for an _arguments spec
action.

 Doc/Zsh/compsys.yo | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/Doc/Zsh/compsys.yo b/Doc/Zsh/compsys.yo
index 89b918d60..b37a752be 100644
--- a/Doc/Zsh/compsys.yo
+++ b/Doc/Zsh/compsys.yo
@@ -3616,8 +3616,18 @@ described using the var(spec)s which are of the form:
 `var(tag)tt(:)var(descr)tt(:)var(action)'.  The var(tag)s are offered using
 tt(_tags) and if the tag is requested, the var(action) is executed with the
 given description var(descr).  The var(action)s are those accepted
-by the tt(_arguments) function (described below), excluding the
-`tt(->)var(state)' and `tt(=)var(...)' forms.
+by the tt(_arguments) function (described below), with the following
+exceptions:
+startitemize()
+itemiz(\
+The `tt(->)var(state)' and `tt(=)var(...)' forms are not supported.
+)
+itemiz(\
+The `tt(LPAR()LPAR()a\:bar b\:baz)tt(RPAR()RPAR())' form does not need
+the colon to be escaped, since the var(spec)s have no colon-separated fields
+after the var(action).
+)
+enditemize()
 
 For example, the var(action) may be a simple function call:
 
-- 
2.33.1