highlighters/regexp/README.md uses an unportable example

[jnooree]

In macOS, the word boundary syntax "\b" is not supported.

I think it's a good idea to add comment for macOS users, to use "[[:<:]]" and "[[:>:]]" rather than "\b".

Thank you for reading.

[danielshahaf]

The stackoverflow question you referenced is entitled Does bash support word boundary regular expressions? and z-sy-h does not support bash. What does () { typeset -pm ZSH\*; for 1; [[ $1 =~ '\bfoo' ]] && echo $1 } foo barfoo output on your system?

[jnooree]

Hello, thanks for responding. This is the output.

typeset -g ZSH_AUTOSUGGEST_ORIGINAL_WIDGET_PREFIX=autosuggest-orig-
typeset -g ZSH_THEME_GIT_PROMPT_CLEAN=$'%{\C-[[34m%})'
typeset -g ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME=zsh_autosuggest_completion_pty
typeset -g ZSH_HIGHLIGHT_VERSION=0.7.2-dev
typeset -g ZSH_AUTOSUGGEST_HIGHLIGHT_STYLE='fg=8'
typeset -g -a ZSH_AUTOSUGGEST_CLEAR_WIDGETS=( history-search-forward history-search-backward history-beginning-search-forward history-beginning-search-backward history-substring-search-up history-substring-search-down up-line-or-beginning-search down-line-or-beginning-search up-line-or-history down-line-or-history accept-line copy-earlier-word )
typeset -g ZSH_VERSION=5.7.1
typeset -g ZSH_PATCHLEVEL=zsh-5.7.1-0-g8b89d0d
typeset -g -A ZSH_HIGHLIGHT_PATTERNS=( )
typeset -g -a ZSH_AUTOSUGGEST_ACCEPT_WIDGETS=( forward-char end-of-line vi-forward-char vi-end-of-line vi-add-eol )
typeset -g ZSH_THEME_RVM_PROMPT_OPTIONS='i v g'
typeset -g -a ZSH_HIGHLIGHT_HIGHLIGHTERS=( main brackets regexp root )
typeset -g ZSH_THEME_TERM_TITLE_IDLE=%n@%m
typeset -g ZSH_THEME=robbyrussell_jnr
typeset -g -a ZSH_AUTOSUGGEST_PARTIAL_ACCEPT_WIDGETS=( forward-word emacs-forward-word vi-forward-word vi-forward-word-end vi-forward-blank-word vi-forward-blank-word-end vi-find-next-char vi-find-next-char-skip )
typeset -g -A ZSH_HIGHLIGHT_STYLES=( [arg0]='fg=green' [assign]=none [autodirectory]='fg=green,underline' [back-dollar-quoted-argument]='fg=cyan' [back-double-quoted-argument]='fg=cyan' [back-quoted-argument]=none [back-quoted-argument-delimiter]='fg=magenta' [bracket-error]='fg=red,bold' [bracket-level-1]='fg=blue,bold' [bracket-level-2]='fg=green,bold' [bracket-level-3]='fg=magenta,bold' [bracket-level-4]='fg=yellow,bold' [bracket-level-5]='fg=cyan,bold' [command-substitution]=none [command-substitution-delimiter]='fg=magenta' [commandseparator]=none [comment]='fg=black,bold' [cursor]=standout [cursor-matchingbracket]=standout [default]=none [dollar-double-quoted-argument]='fg=cyan' [dollar-quoted-argument]='fg=yellow' [double-hyphen-option]=none [double-quoted-argument]='fg=yellow' [global-alias]='fg=cyan' [globbing]='fg=blue' [history-expansion]='fg=blue' [line]='' [named-fd]=none [numeric-fd]=none [path]=underline [path_pathseparator]='' [path_prefix_pathseparator]='' [precommand]='fg=green,underline' [process-substitution]=none [process-substitution-delimiter]='fg=magenta' [rc-quote]='fg=cyan' [redirection]='fg=yellow' [reserved-word]='fg=yellow' [root]=standout [single-hyphen-option]=none [single-quoted-argument]='fg=yellow' [suffix-alias]='fg=green,underline' [unknown-token]='fg=red,bold' )
typeset -g ZSH_HIGHLIGHT_REVISION=HEAD
typeset -g ZSH_THEME_GIT_PROMPT_DIRTY=$'%{\C-[[34m%}) %{\C-[[33m%}✗'
typeset -g ZSH_THEME_TERM_TAB_TITLE_IDLE='%15<..<%~%<<'
typeset -g -A ZSH_HIGHLIGHT_REGEXP=( ['[[:<:]]sudo[[:>:]]']=bold,underline )
typeset -g -a ZSH_AUTOSUGGEST_EXECUTE_WIDGETS=(  )
typeset -g ZSH_THEME_GIT_PROMPT_SUFFIX=$'%{\C-[[00m%}'
typeset -g ZSH_THEME_GIT_PROMPT_PREFIX=$' %{\C-[[01;34m%}git:(%{\C-[[31m%}'
typeset -g -a ZSH_HIGHLIGHT_DIRS_BLACKLIST=(  )
typeset -g ZSH_COMPDUMP=/Users/jnooree/.zcompdump-JNR-MBP-5.7.1
typeset -g ZSH_ARGZERO=-zsh
typeset -g ZSH_CUSTOM=/Users/jnooree/.oh-my-zsh/custom
typeset -g ZSH_NAME=zsh
typeset -g ZSH_THEME_RUBY_PROMPT_SUFFIX=')'
typeset -g -a ZSH_AUTOSUGGEST_IGNORE_WIDGETS=( 'orig-*' beep run-help set-local-history which-command yank yank-pop 'zle-*' )
typeset -g ZSH_CACHE_DIR=/Users/jnooree/.oh-my-zsh/cache
export ZSH=/Users/jnooree/.oh-my-zsh
typeset -g -a ZSH_AUTOSUGGEST_STRATEGY=( history )
typeset -g ZSH_THEME_RUBY_PROMPT_PREFIX='('

[danielshahaf]

Hello, thanks for responding. This is the output.

Thanks. On my system (Debian stable) it does print foo. Could you try it again with «setopt rcmatchpcre» in effect? You can leave the typeset command out this time.

[jnooree]

Well, when I type setopt rcmatchpcre, my terminal says setopt: no such option: rcmatchpcre.
On the other hand, if you've meant setopt rematchpcre, the result is

update_terminal_cwd:12: failed to load module `zsh/pcre': dlopen(/usr/lib/zsh/5.7.1/zsh/pcre.so, 9): image not found
update_terminal_cwd:12: -pcre-match not available for regex

[danielshahaf]

Yes, I did. Sorry for the typo. Would you like to prepare a pull request for this? I'm thinking it'll be much easier to change the example to one that works everywhere than to start explaining differences among regexp flavours, but TIMTOWTDI.

…

Well, when I type `setopt rcmatchpcre`, my terminal says `setopt: no such option: rcmatchpcre`. On the other hand, if you meant `setopt rematchpcre`, the result is ``` update_terminal_cwd:12: failed to load module `zsh/pcre': dlopen(/usr/lib/zsh/5.7.1/zsh/pcre.so, 9): image not found update_terminal_cwd:12: -pcre-match not available for regex ```

[jnooree]

I created one: #747. Please review it, thanks.