Re: Alias call in function fails...

[Daniel Shahaf <d.s@daniel.shahaf.name>]

Daniel Shahaf wrote on Wed, 24 Jun 2020 10:10 +0000:
> Bart Schaefer wrote on Tue, Jun 23, 2020 at 16:40:04 -0700:
> > On Tue, Jun 23, 2020 at 3:55 PM Daniel Shahaf <d.s@daniel.shahaf.name> wrote:  
> > >
> > > I[...] it's perhaps not self-explanatory that nl(1) is an
> > > external command.  
> > 
> > You could use "cat -n" instead.  
> 
> It's unportable.  I'd prefer a runnable example.
> 
> How about:

Extended:

8<--8<--
From 4e1d6b29d42662eb9b6f5d1cf7dc3900c3142762 Mon Sep 17 00:00:00 2001
From: Daniel Shahaf <d.s@daniel.shahaf.name>
Date: Wed, 24 Jun 2020 10:40:23 +0000
Subject: [PATCH 1/2] Extend documentation of global aliases.

---
 Doc/Zsh/builtins.yo | 8 +++++++-
 Doc/Zsh/grammar.yo  | 9 +++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/Doc/Zsh/builtins.yo b/Doc/Zsh/builtins.yo
index ada69c99a..d35cad182 100644
--- a/Doc/Zsh/builtins.yo
+++ b/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
diff --git a/Doc/Zsh/grammar.yo b/Doc/Zsh/grammar.yo
index a4e0c1121..7eabd75ce 100644
--- a/Doc/Zsh/grammar.yo
+++ b/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.

From c554b79da628ea7eb96ff37ddaa456b07004bfe8 Mon Sep 17 00:00:00 2001
From: Daniel Shahaf <d.s@daniel.shahaf.name>
Date: Wed, 24 Jun 2020 10:40:45 +0000
Subject: [PATCH 2/2] Update aliases documentation for the addition of the
 ALIAS_FUNC_DEF option.

---
 Doc/Zsh/grammar.yo | 25 +++++--------------------
 1 file changed, 5 insertions(+), 20 deletions(-)

diff --git a/Doc/Zsh/grammar.yo b/Doc/Zsh/grammar.yo
index 7eabd75ce..2eb2018d2 100644
--- a/Doc/Zsh/grammar.yo
+++ b/Doc/Zsh/grammar.yo
@@ -571,6 +571,11 @@ position (if it could be the first word of a simple command),
 or if the alias is global.
 If the replacement text ends with a space, the next word in the shell input
 is always eligible for purposes of alias expansion.
+
+It is an error for the function name, var(word), in the sh-compatible function
+definition syntax `var(word) tt(+LPAR()+RPAR()) ...' to be a word that resulted
+from alias expansion, unless the tt(ALIAS_FUNC_DEF) option is set.
+
 findex(alias, use of)
 cindex(aliases, global)
 An alias is defined using the tt(alias) builtin; global aliases
@@ -656,26 +661,6 @@ a problem in shell scripts, functions, and code executed with `tt(source)'
 or `tt(.)'.  Consequently, use of functions rather than aliases is
 recommended in non-interactive code.
 
-Note also the unhelpful interaction of aliases and function definitions:
-
-example(alias func='noglob func'
-func+LPAR()RPAR() {
-    echo Do something with $*
-})
-
-Because aliases are expanded in function definitions, this causes the
-following command to be executed:
-
-example(noglob func+LPAR()RPAR() {
-    echo Do something with $*
-})
-
-which defines tt(noglob) as well as tt(func) as functions with the
-body given.  To avoid this, either quote the name tt(func) or use the
-alternative function definition form `tt(function func)'.  Ensuring the
-alias is defined after the function works but is problematic if the
-code fragment might be re-executed.
-
 texinode(Quoting)()(Aliasing)(Shell Grammar)
 sect(Quoting)
 cindex(quoting)