-- Copyright 2006-2018 Mitchell mitchell.att.foicica.com. See License.txt.
|
-- R LPeg lexer.
|
|
local lexer = require('lexer')
|
local token, word_match = lexer.token, lexer.word_match
|
local P, R, S = lpeg.P, lpeg.R, lpeg.S
|
|
local lex = lexer.new('rstats')
|
|
-- Whitespace.
|
lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))
|
|
-- Keywords.
|
lex:add_rule('keyword', token(lexer.KEYWORD, word_match[[
|
break else for if in next repeat return switch try while
|
Inf NA NaN NULL FALSE TRUE
|
]]))
|
|
-- Types.
|
lex:add_rule('type', token(lexer.TYPE, word_match[[
|
array character complex data.frame double factor function integer list logical
|
matrix numeric vector
|
]]))
|
|
-- Identifiers.
|
lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word))
|
|
-- Strings.
|
lex:add_rule('string', token(lexer.STRING, lexer.delimited_range("'", true) +
|
lexer.delimited_range('"', true)))
|
|
-- Comments.
|
lex:add_rule('comment', token(lexer.COMMENT, '#' * lexer.nonnewline^0))
|
|
-- Numbers.
|
lex:add_rule('number', token(lexer.NUMBER, (lexer.float + lexer.integer) *
|
P('i')^-1))
|
|
-- Operators.
|
lex:add_rule('operator', token(lexer.OPERATOR, S('<->+*/^=.,:;|$()[]{}')))
|
|
return lex
|
