Working with the historywords special parameter

[Sven Wischnowsky <wischnow@informatik.hu-berlin.de>]

Felix Rosencrantz wrote:

> I'm trying to create a completer that uses the previous word on the line
> and the special parameter historywords to determine what values current
> word should be.
> 
> It looks to me like there is no single expression that can be used to
> get just the list of all the elements that match an expression from an
> array.  It seems like you need to iterate over the elements of an array
> via an expression like:
> 
>     #the_word is $words[CURRENT-1]
>     cnt=2
>     words=()
>     while [[ $historywords[(in:cnt:)the_word] -lt  $#historywords  ]] ; do
>        words=($words $historywords[$historywords[(in:cnt:)the_word]-1]
>        let "cnt = cnt + 1" 
>     done
> 
> Is there a faster way to do this?

I don't see anything faster than:

  local i length cnt=2 words hist
  words=()
  hist=($historywords)
  length=$#hist
  while (( ( i=$hist[(in:cnt++:)$the_word] ) <= length )); do
    words=($words $hist[i-1])
  done

Maybe ${(Mk)historywords:#$the_word} should expand to the list of
the indices of the words equal to $the_word.

> ...
> 
> Would anyone object to a new special parameter (maybe historywordsnums)
> that has corresponding elements to historywords saying with which
> history line the word is associated?  I ask since one of the problems
> with this completer is that it picks up false "matches" when the
> previous word is the last word of a previous command, it gets the next command.
> 
> It would be nice to be able to determine if a word is the last word of
> the line, or what the first word of the line is.

Or maybe give that new array another name and let it report not only
the line but also other information, e.g. the position on the line
(word number and character positions so that that could be used to
index into the values of the history assoc).


Bye
  Sven

-- 
Sven Wischnowsky                    wischnow@informatik.hu-berlin.de