1 files changed, 52 insertions, 0 deletions
diff --git a/lua/lexers/r.lua b/lua/lexers/r.lua
new file mode 100644
index 0000000..7ac801e
--- /dev/null
+++ b/lua/lexers/r.lua
@@ -0,0 +1,52 @@
+-- Copyright 2006-2024 Mitchell. See LICENSE.
+-- R 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('r')
+
+-- 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', 'F', 'T',
+	-- Frequently used operators.
+	'|>', '%%', '%*%', '%/%', '%in%', '%o%', '%x%'
+}))
+
+-- Types.
+lex:add_rule('type', token(lexer.TYPE, word_match{
+	'array', 'character', 'closure', 'complex', 'data.frame', 'double', 'environment', 'expression',
+	'externalptr', 'factor', 'function', 'integer', 'list', 'logical', 'matrix', 'numeric',
+	'pairlist', 'promise', 'raw', 'symbol', 'vector'
+}))
+
+-- Identifiers.
+lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word))
+
+-- Strings.
+local sq_str = lexer.range("'", true)
+local dq_str = lexer.range('"', true)
+lex:add_rule('string', token(lexer.STRING, sq_str + dq_str))
+
+-- Comments.
+lex:add_rule('comment', token(lexer.COMMENT, lexer.to_eol('#')))
+
+-- Numbers.
+lex:add_rule('number', token(lexer.NUMBER, (lexer.number * P('i')^-1) * P('L')^-1))
+
+-- Operators.
+lex:add_rule('operator', token(lexer.OPERATOR, S('<->+*/^=.,:;|$()[]{}')))
+
+-- Folding
+lex:add_fold_point(lexer.OPERATOR, '(', ')')
+lex:add_fold_point(lexer.OPERATOR, '[', ']')
+lex:add_fold_point(lexer.OPERATOR, '{', '}')
+
+lexer.property['scintillua.comment'] = '#'
+
+return lex