-- Copyright 2006-2022 Mitchell. See LICENSE.
-- Desktop Entry LPeg lexer.

local lexer = require('lexer')
local token, word_match = lexer.token, lexer.word_match
local P, S = lpeg.P, lpeg.S

local lex = lexer.new('desktop')

-- Whitespace.
lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))

-- Keys.
lex:add_rule('key', token('key', word_match{
  'Type', 'Version', 'Name', 'GenericName', 'NoDisplay', 'Comment', 'Icon', 'Hidden', 'OnlyShowIn',
  'NotShowIn', 'TryExec', 'Exec', 'Exec', 'Path', 'Terminal', 'MimeType', 'Categories',
  'StartupNotify', 'StartupWMClass', 'URL'
}))
lex:add_style('key', lexer.styles.keyword)

-- Values.
lex:add_rule('value', token('value', word_match('true false')))
lex:add_style('value', lexer.styles.constant)

-- Identifiers.
lex:add_rule('identifier', lexer.token(lexer.IDENTIFIER, lexer.alpha * (lexer.alnum + S('_-'))^0))

-- Group headers.
local bracketed = lexer.range('[', ']')
lex:add_rule('header', lexer.starts_line(token('header', bracketed)))
lex:add_style('header', lexer.styles.label)

-- Locales.
lex:add_rule('locale', token('locale', bracketed))
lex:add_style('locale', lexer.styles.class)

-- Strings.
lex:add_rule('string', token(lexer.STRING, lexer.range('"')))

-- Comments.
lex:add_rule('comment', token(lexer.COMMENT, lexer.to_eol('#')))

-- Numbers.
lex:add_rule('number', token(lexer.NUMBER, lexer.number))

-- Field codes.
lex:add_rule('code', lexer.token('code', '%' * S('fFuUdDnNickvm')))
lex:add_style('code', lexer.styles.variable)

-- Operators.
lex:add_rule('operator', token(lexer.OPERATOR, S('=')))

return lex