-- Copyright 2006-2023 Mitchell. See LICENSE.
-- JavaScript LPeg lexer.
local lexer = lexer
local P, S, B = lpeg.P, lpeg.S, lpeg.B

local lex = lexer.new(...)

-- Keywords.
lex:add_rule('keyword', lex:tag(lexer.KEYWORD, lex:word_match(lexer.KEYWORD)))

-- Types.
lex:add_rule('type', lex:tag(lexer.TYPE, lex:word_match(lexer.TYPE)))

-- Functions.
local builtin_func = -B('.') *
                         lex:tag(lexer.FUNCTION_BUILTIN,
                                 lex:word_match(lexer.FUNCTION_BUILTIN))
local func = lex:tag(lexer.FUNCTION, lexer.word)
local method = B('.') * lex:tag(lexer.FUNCTION_METHOD, lexer.word)
lex:add_rule('function',
             (builtin_func + method + func) * #(lexer.space ^ 0 * '('))

-- Constants.
lex:add_rule('constant', lex:tag(lexer.CONSTANT_BUILTIN,
                                 lex:word_match(lexer.CONSTANT_BUILTIN)))

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

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

-- Strings.
local sq_str = lexer.range("'")
local dq_str = lexer.range('"')
local bq_str = lexer.range('`')
local string = lex:tag(lexer.STRING, sq_str + dq_str + bq_str)
local regex_str = lexer.after_set('+-*%^!=&|?:;,([{<>',
                                  lexer.range('/', true) * S('igm') ^ 0)
local regex = lex:tag(lexer.REGEX, regex_str)
lex:add_rule('string', string + regex)

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

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

-- Fold points.
lex:add_fold_point(lexer.OPERATOR, '{', '}')
lex:add_fold_point(lexer.COMMENT, '/*', '*/')

-- Word lists.
lex:set_word_list(lexer.KEYWORD, {
    'abstract', 'async', 'await', 'boolean', 'break', 'byte', 'case', 'catch',
    'char', 'class', 'const', 'continue', 'debugger', 'default', 'delete', 'do',
    'double', 'else', 'enum', 'export', 'extends', 'false', 'final', 'finally',
    'float', 'for', 'function', 'get', 'goto', 'if', 'implements', 'import',
    'in', 'instanceof', 'int', 'interface', 'let', 'long', 'native', 'new',
    'null', 'of', 'package', 'private', 'protected', 'public', 'return', 'set',
    'short', 'static', 'super', 'switch', 'synchronized', 'this', 'throw',
    'throws', 'transient', 'true', 'try', 'typeof', 'var', 'void', 'volatile',
    'while', 'with', 'yield'
})

lex:set_word_list(lexer.TYPE, {
    -- Fundamental objects.
    'Object', 'Function', 'Boolean', 'Symbol', -- Error Objects.
    'Error', 'AggregateError', 'EvalError', 'InternalError', 'RangeError',
    'ReferenceError', 'SyntaxError', 'TypeError', 'URIError',
    -- Numbers and dates.
    'Number', 'BigInt', 'Math', 'Date', -- Text Processing.
    'String', 'RegExp', -- Indexed collections.
    'Array', 'Int8Array', 'Uint8Array', 'Uint8ClampedArray', 'Int16Array',
    'Uint16Array', 'Int32Array', 'Uint32Array', 'Float32Array', 'Float64Array',
    'BigInt64Array', 'BigUint64Array', -- Keyed collections.
    'Map', 'Set', 'WeakMap', 'WeakSet', -- Structured data.
    'ArrayBuffer', 'SharedArrayBuffer', 'Atomics', 'DataView', 'JSON',
    -- Control abstraction objects.
    'GeneratorFunction', 'AsyncGeneratorFunction', 'Generator',
    'AsyncGenerator', 'AsyncFunction', 'Promise', -- Reflection.
    'Reflect', 'Proxy', -- Other.
    'Intl', 'WebAssembly'
})

lex:set_word_list(lexer.FUNCTION_BUILTIN, {
    'eval', 'isFinite', 'isNaN', 'parseFloat', 'parseInt', 'decodeURI',
    'decodeURIComponent', 'encodeURI', 'encodeURIComponent'
})

lex:set_word_list(lexer.CONSTANT_BUILTIN,
                  'Infinity NaN undefined globalThis arguments')

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

return lex
