Re: Bug#537596: regression: parse error near `()' in function definition

[Peter Stephenson <pws@csr.com>]

On Sun, 19 Jul 2009 23:20:41 +0000
Clint Adams <schizo@debian.org> wrote:
> On Sun, Jul 19, 2009 at 07:16:51PM +0200, martin f krafft wrote:
> > % eval 'lt() { (_lt-en $*; _en-lt $*) | more }'
> > zsh: parse error near `()'
> > 
> > Alright, so lt is special:
> > 
> > % which lt
> > lt: aliased to ls -lt

Assuming lt was defined as an alias first, this has always been the wrong
thing to do:

% alias lt="one two"
% eval 'lt() { (_lt-en $*; _en-lt $*) | more }'
% which one two
one () {
        (
                _lt-en $*
                _en-lt $*
        ) | more
}
two () {
        (
                _lt-en $*
                _en-lt $*
        ) | more
}

This is not a new feature; it's been mentioned in the FAQ for many years.


2.3: Why do my csh aliases not work?  (Plus other alias pitfalls.)

...

  There is one other serious problem with aliases: consider

    alias l='/bin/ls -F'
    l() { /bin/ls -la "$@" | more }

  `l' in the function definition is in command position and is expanded
  as an alias, defining `/bin/ls' and `-F' as functions which call
  `/bin/ls', which gets a bit recursive.  This can be avoided if you use
  `function' to define a function, which doesn't expand aliases.  It is
  possible to argue for extra warnings somewhere in this mess.

  Bart Schaefer's rule is:  Define first those aliases you expect to
  use in the body of a function, but define the function first if the
  alias has the same name as the function.

-- 
Peter Stephenson <pws@csr.com>            Software Engineer
Tel: +44 (0)1223 692070                   Cambridge Silicon Radio Limited
Churchill House, Cambridge Business Park, Cowley Road, Cambridge, CB4 0WZ, UK


'member of the CSR plc group of companies. CSR plc registered in England and Wales, registered number 4187346, registered office Churchill House, Cambridge Business Park, Cowley Road, Cambridge, CB4 0WZ, United Kingdom'