-- Copyright 2006-2023 Martin Morawetz. See LICENSE.
-- Matlab LPeg lexer.
-- Based off of lexer code by Mitchell.
local lexer = require('lexer')
local token, word_match = lexer.token, lexer.word_match
local P, S = lpeg.P, lpeg.S

local lex = lexer.new('matlab')

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

-- Keywords.
lex:add_rule('keyword', token(lexer.KEYWORD, word_match({
    'break', 'case', 'catch', 'continue', 'do', 'else', 'elseif', 'end',
    'end_try_catch', 'end_unwind_protect', 'endfor', 'endif', 'endswitch',
    'endwhile', 'for', 'function', 'endfunction', 'global', 'if', 'otherwise',
    'persistent', 'replot', 'return', 'static', 'switch', 'try', 'until',
    'unwind_protect', 'unwind_protect_cleanup', 'varargin', 'varargout', 'while'
}, true)))

-- Functions.
lex:add_rule('function', token(lexer.FUNCTION, word_match {
    'abs', 'any', 'argvatan2', 'axes', 'axis', 'ceil', 'cla', 'clear', 'clf',
    'columns', 'cos', 'delete', 'diff', 'disp', 'doc', 'double', 'drawnow',
    'exp', 'figure', 'find', 'fix', 'floor', 'fprintf', 'gca', 'gcf', 'get',
    'grid', 'help', 'hist', 'hold', 'isempty', 'isnull', 'length', 'load',
    'log', 'log10', 'loglog', 'max', 'mean', 'median', 'min', 'mod', 'ndims',
    'numel', 'num2str', 'ones', 'pause', 'plot', 'printf', 'quit', 'rand',
    'randn', 'rectangle', 'rem', 'repmat', 'reshape', 'round', 'rows', 'save',
    'semilogx', 'semilogy', 'set', 'sign', 'sin', 'size', 'sizeof',
    'size_equal', 'sort', 'sprintf', 'squeeze', 'sqrt', 'std', 'strcmp',
    'subplot', 'sum', 'tan', 'tic', 'title', 'toc', 'uicontrol', 'who',
    'xlabel', 'ylabel', 'zeros'
}))

-- Constants.
lex:add_rule('constant', token(lexer.CONSTANT, word_match(
                                   'EDITOR I IMAGEPATH INFO_FILE J LOADPATH OCTAVE_VERSION PAGER PS1 PS2 PS4 PWD')))

-- Variable.
lex:add_rule('variable', token(lexer.VARIABLE, word_match {
    'ans', 'automatic_replot', 'default_return_value', 'do_fortran_indexing',
    'define_all_return_values', 'empty_list_elements_ok', 'eps', 'false',
    'gnuplot_binary', 'ignore_function_time_stamp', 'implicit_str_to_num_ok',
    'Inf', 'inf', 'NaN', 'nan', 'ok_to_lose_imaginary_part',
    'output_max_field_width', 'output_precision', 'page_screen_output', 'pi',
    'prefer_column_vectors', 'prefer_zero_one_indexing', 'print_answer_id_name',
    'print_empty_dimensions', 'realmax', 'realmin', 'resize_on_range_error',
    'return_last_computed_value', 'save_precision', 'silent_functions',
    'split_long_rows', 'suppress_verbose_help_message', 'treat_neg_dim_as_zero',
    'true', 'warn_assign_as_truth_value', 'warn_comma_in_global_decl',
    'warn_divide_by_zero', 'warn_function_name_clash',
    'whitespace_in_literal_matrix'
}))

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

-- Strings.
local sq_str = lexer.range("'", true)
local dq_str = lexer.range('"')
local bq_str = lexer.range('`')
lex:add_rule('string', token(lexer.STRING, sq_str + dq_str + bq_str))

-- Comments.
local line_comment = lexer.to_eol(S('%#'))
local block_comment = lexer.range('%{', '%}')
lex:add_rule('comment', token(lexer.COMMENT, block_comment + line_comment))

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

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

-- Fold points.
lex:add_fold_point(lexer.KEYWORD, 'if', 'end')
lex:add_fold_point(lexer.KEYWORD, 'for', 'end')
lex:add_fold_point(lexer.KEYWORD, 'while', 'end')
lex:add_fold_point(lexer.KEYWORD, 'switch', 'end')
lex:add_fold_point(lexer.OPERATOR, '(', ')')
lex:add_fold_point(lexer.OPERATOR, '[', ']')
lex:add_fold_point(lexer.COMMENT, '%{', '%}')

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

return lex
