Why sourcing a file is not faster than doing a loop with eval, zle -N

[Sebastian Gniazdowski <psprint@xxxxxxxxxxx>]

Hello,
I've tried to optimize my fast-syntax-highlighting. The idea is simple, instead of a loop:

  for cur_widget in $widgets_to_bind; do
    case $widgets[$cur_widget] in
        ...
        builtin) eval "_zsh_highlight_widget_${(q)prefix}-${(q)cur_widget}() { _call_widget .${(q)cur_widget} -- \"\$@\" }"
               zle -N $cur_widget _zsh_highlight_widget_$prefix-$cur_widget;;
  ...
  ...


I do, in the same loop:
    ...
    print -r "zle -N" "$prefix-$cur_widget" "${widgets[$cur_widget]#*:}" >>| ~/.fsh_cache
    ...


and so on, to then only detect ~/.fsh_cache, and source it, skipping the loop. Times of "zsh -i -c exit" are:

- normal FSH:          0.3968 sec on average
- cache-feature FSH:   0.4329 sec on average
- zcompiled cache:     0.3831 sec on average

So, only after compiling ~/.fsh_cache, I get slightly better time, normally it is ~30 ms slower. I would expect this to be always and more faster. Why it is not?

I now suspect that maybe there's more parsing – loop doesn't have 554 lines like ~/.fsh_cache, and is parsed quickier.

Test data: https://github.com/zdharma/hacking-private/tree/master/FSH

-- 
Sebastian Gniazdowski
psprint /at/ zdharma.org