# http://complang.org/ragel
# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾

# ragel.kak does not try to detect host language.

# Detection
# ‾‾‾‾‾‾‾‾‾

hook global BufSetOption mimetype=text/x-ragel %{
    set buffer filetype ragel
}

hook global BufCreate .*[.](ragel|rl) %{
    set buffer filetype ragel
}

# Highlighters
# ‾‾‾‾‾‾‾‾‾‾‾‾

addhl -group / regions -default code ragel \
    string  '"' (?<!\\)(\\\\)*"         '' \
    string  "'" "'"                     '' \
    comment '#' '$'                     ''

addhl -group /ragel/string  fill string
addhl -group /ragel/comment fill comment

addhl -group /ragel/code regex \<(true|false)\> 0:value
addhl -group /ragel/code regex '%%\{|\}%%|<\w+>' 0:identifier
addhl -group /ragel/code regex :=|=>|->|:>|:>>|<: 0:operator
addhl -group /ragel/code regex \<(action|alnum|alpha|any|ascii|case|cntrl|contained|context|data|digit|empty|eof|err|error|exec|export|exports|extend|fblen|fbreak|fbuf|fc|fcall|fcurs|fentry|fexec|fgoto|fhold|first_final|fnext|fpc|fret|from|fstack|ftargs|graph|import|include|init|inwhen|lerr|lower|machine|nocs|noend|noerror|nofinal|noprefix|outwhen|postpop|prepush|print|punct|range|space|start|to|upper|when|write|xdigit|zlen)\> 0:keyword

# Commands
# ‾‾‾‾‾‾‾‾

def -hidden _ragel_filter_around_selections %{
    eval -draft -itersel %{
        exec <a-x>
        # remove trailing white spaces
        try %{ exec -draft s \h+$ <ret> d }
    }
}

def -hidden _ragel_indent_on_char "
    eval -draft -itersel %_
        # align closer token to its opener when alone on a line
        try %/ exec -draft <a-h> <a-k> ^\h+[]})]$ <ret>        m         s \`|.\' <ret> 1<a-&> /
        try %/ exec -draft <a-h> <a-k> ^\h+  [*]$ <ret> <a-?> [*]$ <ret> s \`|.\' <ret> 1<a-&> /
    _
"

def -hidden _ragel_indent_on_new_line "
    eval -draft -itersel '
        # preserve previous line indent
        try %{ exec -draft <space> K <a-&> }
        # filter previous line
        try %{ exec -draft k : _ragel_filter_around_selections <ret> }
        # copy _#_ comment prefix and following white spaces
        try %{ exec -draft k x s ^\h*\K#\h* <ret> y j p }
        # indent after lines ending with opener token
        try %_ exec -draft k x <a-k> [[{(*]$ <ret> j <a-gt> _
    '
"

# Initialization
# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾

hook global WinSetOption filetype=ragel %{
    addhl ref ragel

    hook window InsertEnd  .* -group ragel-hooks  _ragel_filter_around_selections
    hook window InsertChar .* -group ragel-indent _ragel_indent_on_char
    hook window InsertChar \n -group ragel-indent _ragel_indent_on_new_line
}

hook global WinSetOption filetype=(?!ragel).* %{
    rmhl ragel
    rmhooks window ragel-indent
    rmhooks window ragel-hooks
}