2020
https://jonathanh.co.uk/blog/current-word-completion.html

To enable compinit, put the following to your .zshrc

autoload -U compinit
compinit

Note: .zcompdump is created the first time
Note: compinstall func can guide you through the completion install process

zmodload zsh/complist - need for using pager for displaying long list of completions


zstyle

The actual make-up for contexts:

:completion:function:completer:command:argument:tag

The least-specific context pattern is (usefull for default values):
:completion:*

tag is the last component of zstyle.

zstyle ':completion:*:messages' format %d
	restrict the format to the messages, tagged by 'messages' tag.
zstyle ':completion:*:warnings' format 'No matches'
	If there are no possible matches, warning-tag is used.	
zstyle ':completion:*:descriptios' format %B%d%b
	Prints completion-description above the list in bold.
	Note: more than one type of things can be completed [e.x - no<tab>].
zstyle ':completion:*' group-name ''
	This will fix the situation for the above case (more than one group).
zstyle ':completion:*:manuals' separate-sections true
	Causes completion matches to be further sub-divided
zstyle ':completion:*' verbose yes
	Print descriptions against each match.
zstyle ':completion:*' list-separator '#'
	Sets list-separator (to separated descriptor from option) for the above case
zstyle ':completion:*' auto-description 'specify: %d'
	Sets auto-description
zstyle ':completion:*:default' list-prompt '%S%M matches %s'
	Specify the format of list-prompt, displayed at the bottom of the screen:
		%M - spec-var
	Note: listscrol key-map is used for controlling the pager keys:
		bindkey -M listscrol q send-break
zstyle ':completion:*:default' menu 'select=0'
	Enable menu selection (0 - how many matches should be before menu selection is started).
	Note: menuselect key-map is used for controlling the selection keys.
zstyle ':completion:*' matcher-list 'm:{a-zA-Z}={A-Za-z}'
	Apply case-insensitive matching.
zstyle ':completion:*' insert-tab true
	Do not complete empty commands (result of pasting text containging tabs).
zstyle ':completion:*:*files' ignore-patterns '*?.o' '*?~'
	Ignore the menioned patterns when completing.
zstyle ':completion:*:*:cd:*' ignore-patterns '(*/|)(CVS|SCCS)'
	Exclude CVS and SCCS dirs but only for the cd command.
zstyle ':completion::*:(cvs-add|less|rm|vi):*' ignore-line true
	Ignore the completions that already present in the current line - usefull for rm, vi, ...




zsh options

auto_list (on by default)
	list all the completions if many.
list_beep
	beep while displaying a completion list.
menu_complete
	Set menu completion (There is also menu-complete editor function for binding).
auto_menu (on by default)
	Causes menu completion to be used after a second consecutive request for completion (pressing Tab twice).
complete_in_word
	Prefix completion - matching by expecting the chars after the cursor to be at the end of any matches.
auto_remove_slash (on by default)
	Auto-remove slash for some cases (like rm ...).