-- Copyright 2006-2023 Mitchell. See LICENSE.
-- Lisp 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('lisp')

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

-- Keywords.
lex:add_rule('keyword', token(lexer.KEYWORD, word_match {
    'defclass', 'defconstant', 'defgeneric', 'define-compiler-macro',
    'define-condition', 'define-method-combination', 'define-modify-macro',
    'define-setf-expander', 'define-symbol-macro', 'defmacro', 'defmethod',
    'defpackage', 'defparameter', 'defsetf', 'defstruct', 'deftype', 'defun',
    'defvar', --
    'abort', 'assert', 'block', 'break', 'case', 'catch', 'ccase', 'cerror',
    'cond', 'ctypecase', 'declaim', 'declare', 'do', 'do*', 'do-all-symbols',
    'do-external-symbols', 'do-symbols', 'dolist', 'dotimes', 'ecase', 'error',
    'etypecase', 'eval-when', 'flet', 'handler-bind', 'handler-case', 'if',
    'ignore-errors', 'in-package', 'labels', 'lambda', 'let', 'let*', 'locally',
    'loop', 'macrolet', 'multiple-value-bind', 'proclaim', 'prog', 'prog*',
    'prog1', 'prog2', 'progn', 'progv', 'provide', 'require', 'restart-bind',
    'restart-case', 'restart-name', 'return', 'return-from', 'signal',
    'symbol-macrolet', 'tagbody', 'the', 'throw', 'typecase', 'unless',
    'unwind-protect', 'when', 'with-accessors', 'with-compilation-unit',
    'with-condition-restarts', 'with-hash-table-iterator',
    'with-input-from-string', 'with-open-file', 'with-open-stream',
    'with-output-to-string', 'with-package-iterator', 'with-simple-restart',
    'with-slots', 'with-standard-io-syntax', --
    't', 'nil'
}))

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

-- Strings.
lex:add_rule('string', token(lexer.STRING,
                             "'" * word + lexer.range('"') + '#\\' * lexer.any))

-- Comments.
local line_comment = lexer.to_eol(';')
local block_comment = lexer.range('#|', '|#')
lex:add_rule('comment', token(lexer.COMMENT, line_comment + block_comment))

-- Numbers.
lex:add_rule('number', token(lexer.NUMBER, P('-') ^ -1 * lexer.digit ^ 1 *
                                 (S('./') * lexer.digit ^ 1) ^ -1))

-- Operators.
lex:add_rule('operator', token(lexer.OPERATOR, S('<>=*/+-`@%()')))

-- Fold points.
lex:add_fold_point(lexer.OPERATOR, '(', ')')
lex:add_fold_point(lexer.OPERATOR, '[', ']')
lex:add_fold_point(lexer.OPERATOR, '{', '}')
lex:add_fold_point(lexer.COMMENT, '#|', '|#')

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

return lex
