-- Copyright 2006-2023 Mitchell. See LICENSE.
-- Objective C 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('objective_c')

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

-- Keywords.
lex:add_rule('keyword', token(lexer.KEYWORD, word_match {
    -- From C.
    'asm', 'auto', 'break', 'case', 'const', 'continue', 'default', 'do',
    'else', 'extern', 'false', 'for', 'goto', 'if', 'inline', 'register',
    'return', 'sizeof', 'static', 'switch', 'true', 'typedef', 'void',
    'volatile', 'while', 'restrict', '_Bool', '_Complex', '_Pragma',
    '_Imaginary', -- Objective C.
    'oneway', 'in', 'out', 'inout', 'bycopy', 'byref', 'self', 'super',
    -- Preprocessor directives.
    '@interface', '@implementation', '@protocol', '@end', '@private',
    '@protected', '@public', '@class', '@selector', '@encode', '@defs',
    '@synchronized', '@try', '@throw', '@catch', '@finally', -- Constants.
    'TRUE', 'FALSE', 'YES', 'NO', 'NULL', 'nil', 'Nil', 'METHOD_NULL'
}))

-- Types.
lex:add_rule('type', token(lexer.TYPE, word_match(
                               'apply_t id Class MetaClass Object Protocol retval_t SEL STR IMP BOOL TypedStream')))

-- Strings.
local sq_str = P('L') ^ -1 * lexer.range("'", true)
local dq_str = P('L') ^ -1 * lexer.range('"', true)
lex:add_rule('string', token(lexer.STRING, sq_str + dq_str))

-- Identifiers.
lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word))

-- Comments.
local line_comment = lexer.to_eol('//', true)
local block_comment = lexer.range('/*', '*/')
lex:add_rule('comment', token(lexer.COMMENT, line_comment + block_comment))

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

-- Preprocessor.
lex:add_rule('preprocessor', #lexer.starts_line('#') *
                 token(lexer.PREPROCESSOR, '#' * S('\t ') ^ 0 * word_match {
        'define', 'elif', 'else', 'endif', 'error', 'if', 'ifdef', 'ifndef',
        'import', 'include', 'line', 'pragma', 'undef', 'warning'
    }))

-- Operators.
lex:add_rule('operator', token(lexer.OPERATOR, S('+-/*%<>!=^&|?~:;.()[]{}')))

-- Fold symbols.
lex:add_fold_point(lexer.PREPROCESSOR, 'region', 'endregion')
lex:add_fold_point(lexer.PREPROCESSOR, 'if', 'endif')
lex:add_fold_point(lexer.PREPROCESSOR, 'ifdef', 'endif')
lex:add_fold_point(lexer.PREPROCESSOR, 'ifndef', 'endif')
lex:add_fold_point(lexer.OPERATOR, '{', '}')
lex:add_fold_point(lexer.COMMENT, '/*', '*/')

lexer.property['scintillua.comment'] = '//'

return lex
