users/24959/0001: Extend documentation of global aliases.

ChangeLog

@@ -1,3 +1,8 @@
+2020-06-27  Daniel Shahaf  <d.s@daniel.shahaf.name>
+
+	* users/24959/0001: Doc/Zsh/builtins.yo, Doc/Zsh/grammar.yo:
+	Extend documentation of global aliases.
+
 2020-06-26  Daniel Shahaf  <d.s@daniel.shahaf.name>
 
 	* unposted: Doc/Zsh/contrib.yo, Doc/Zsh/expn.yo,

Doc/Zsh/builtins.yo

@@ -105,7 +105,13 @@ For each var(name) with a corresponding var(value), define an alias
 with that value.  A trailing space in var(value) causes the next word
 to be checked for alias expansion.  If the tt(-g) flag is present,
 define a global alias; global aliases are expanded even if they do not
-occur in command position.
+occur in command position:
+
+example(% perldoc --help 2>&1 | grep 'built-in functions'
+    -f   Search Perl built-in functions
+% alias -g HG='--help 2>&1 | grep'
+% perldoc HG 'built-in functions'
+    -f   Search Perl built-in functions)
 
 If the tt(-s) flag is present, define a suffix alias: if the command
 word on a command line is in the form `var(text)tt(.)var(name)', where

Doc/Zsh/grammar.yo

@@ -597,6 +597,15 @@ word, e.g. tt(\foo).  Any form of quoting works, although there is
 nothing to prevent an alias being defined for the quoted form such as
 tt(\foo) as well.
 
+In particular, note that quoting must be used when using tt(unalias) to remove
+global aliases:
+
+example(% alias -g foo=bar
+% unalias foo
+unalias: no such hash table element: bar
+% unalias \foo
+% )
+
 When tt(POSIX_ALIASES) is set, only plain unquoted strings are eligible
 for aliasing.  The tt(alias) builtin does not reject ineligible aliases,
 but they are not expanded.