I've replaced near all if [[ ]] calls with [[ ]] in
zsh-syntax-highlighting's main-highlighter.zsh, and no performance was
gained. So unless there's a tight loop, if [[ doesn't slow down when
compared to [[ alone.


BTW. Running attached parse.zsh on toparse.zsh with zsh-5.2 in shebang
produces following difference in generated region_highlight, to
/bin/zsh (OS X 5.0.8):

439c439
< 3878 3885 fg=yellow
---
> 3878 3885 fg=green

The same difference for 5.1.1, 5.1. Zsh-5.0.8-dev-0 doesn't produce
the difference, and 5.0.8-dev-1 produces it, so apparently that's
where the difference starts appearing, compared to OS X 5.0.8
/bin/zsh.

Best regards,
Sebastian Gniazdowski