Speed of ZSH

["Andrej Borsenkow" <borsenkow.msk@xxxxxx>]

I recently needed to do a quick prototyping, and selected zsh just for the
easy programming. The task was: I get a file with records of length 2040
characters and need to extract several (~100) fixed width fields and write
them out separated by tabs. I had a list of fields in the form n1-n2, so I
just vi'ed them :-) to get $line[n1,n2].

The problems I got were:

1. I found, that it is near to impossible to ``read'' line without breaking
it on IFS. ``read -k'' did not work :-( After some play I found, that
unsetting IFS helps - not very nice. How useful would it be to add a flag
that says "read entire line in scalar variable without splitting"?

2. It is impossible to ``print'' arguments separated by user defined string
(only NL or NUL). I had to make an array out of fields, and then print it
with explicit join:

fields=( $line[n1,n2] ...)
print ${(j/\t/)fields}

(Aside: how useful would it be to add flag to ``print'' to define
separator?)

After doing it I found, that ZSH needs several seconds for a file with 28
records! That is really too much for such a simple task. I suspect, the
reason is constant reallocation of memory when first array is created
(remember, it has about 100 elements) and then when it is joined.

If anybody interested, I could recompile with profiling.

I don't use zsh-mem mostly because I don't understand, what it actually is
:-)

/andrej