rainbow.kak

declare-option -hidden range-specs rainbow
declare-option regex rainbow_opening "[\[{(]"
declare-option bool rainbow_highlight_background false

declare-option str-list rainbow_faces "bright-red" "bright-green" "bright-yellow" "bright-blue" "bright-magenta" "bright-cyan"

define-command rainbow %{
    set-option window rainbow "%val{timestamp}"
    try %{
        add-highlighter window/ ranges rainbow
    }
    evaluate-commands -save-regs '/' -draft %{
        set-register / "%opt{rainbow_opening}"
        execute-keys \%
        try %{
            rainbow-selection 0
        }
    }
}

define-command -hidden rainbow-selection -params 1 %{
    evaluate-commands %sh{
        index=$1
        eval "set -- $kak_quoted_opt_rainbow_faces"
        length=$#
        next_index=$(( (index + 1) % (length - 1) ))
        index=$(( index + 1 ))
        eval face=\$$index
        select_ends=""
        if ! $kak_opt_rainbow_highlight_background; then
            select_ends="execute-keys <a-S>"
        fi
        echo "
            execute-keys s<ret>m
            evaluate-commands -draft %{
                $select_ends
                evaluate-commands -itersel %{
                    set-option -add window rainbow \"%val{selection_desc}|$face\"
                }
            }
            execute-keys <a-K>\A..\z<ret> #if there is no content do not recurse
            evaluate-commands -itersel -draft %{
                execute-keys H<a-\;>L
                try %{
                    rainbow-selection $next_index
                }
            }
        "
    }
}

define-command rainbow-enable %{
    # Rainbow delimiters should be highlighted when:
    # * rainbow-enable is called
    rainbow
    # * A deleting command is called in Normal mode
    hook -group rainbow window NormalKey "(?:d|c|P|p|R|<a-P>|<a-p>|<a-R>)" %{ rainbow }
    # * An opening delimiter key is pressed in Insert mode
    # | NOTE: This is necessary to play nice with auto-pairs, as the characters
    # | inserted by that plugin do not seem to trigger the InsertChar hook.
    hook -group rainbow window InsertKey "(?:\(|\[|\{)" %{ rainbow }
    # * A closing delimiter is inserted in Insert mode (allows for operation with auto-pairs disabled.)
    # | JANK ALERT: kak appears to have ~opinions~ on the order in which
    # | hooks are added. If this hook is added before the previous one,
    # | it breaks both this command and rainbow-disable.
    hook -group rainbow window InsertChar "(?:\)|\]|\})" %{ rainbow }
}

define-command rainbow-disable %{
    remove-highlighter window/ranges_rainbow
    remove-hooks window rainbow
}