Re: Associative arrays and memory

[Sven Wischnowsky <wischnow@xxxxxxxxxxxxxxxxxxxxxxx>]

Bart Schaefer wrote:

> ...
> 
> On Nov 16, 10:54am, Sven Wischnowsky wrote:
> } Subject: Re: Associative arrays and memory
> }
> } (Every time I think about this I can't help remembering the discussion 
> } about a new option system, am I the only one?)
> 
> You are not.  However, I thought the "new options system" mainly meant
> new syntax for "namespaces"?  In which case it doesn't really help with
> any of these questions about special parameters.  It could remove one
> level of indirection in the save/restore loops, I guess.
> 

Yep. This is just another place where I could imagine assoc arrays to
be used.

> ...
>
> The problem (with or without your magic [(x)...] syntax) is that an
> associative array is unordered, but presumably we want some fixed order
> to the interpretation of completions when multiple patterns match the
> command.  (If we're using an associative array for completions, how do
> you implement the equivalent of the -tc option?)

Right, I forgot about that.

> } (the question is: are there other uses
> } where such a feature might be interesting to have
> 
> I think for a shell-script-level feature, this has gone over the edge of
> reasonable complexity.  If perl doesn't have this feature, we should avoid
> it too. :-}
> 
> } and: if we have a
> } way to get a list of matching entries, should we make this with a new
> } modifier flag that can be combined with `i', `I', `r', and `R' so that 
> } all of them give a list, not only the first matching one?).
> 
> Maybe it's because it's 4:30am, but I don't understand that part at all.

I was thinking about something like the `g' history modifier:

  % typeset -A foo
  % foo[a]=hello
  % foo[b]=world
  % echo $foo[(i)?]
  a
  % echo $foo[(r)*l*]
  hello
  % echo $foo[(xi)*l*]
  a b
  % echo $foo[(xr)*l*]
  hello world

As a side effect, we could use `$foo[(xi)*]' instead of `${(k)foo}'
but the latter would still be faster.

Bye
 Sven


--
Sven Wischnowsky                         wischnow@xxxxxxxxxxxxxxxxxxxxxxx