1 files changed, 78 insertions, 0 deletions
diff --git a/lua/lexers/icon.lua b/lua/lexers/icon.lua
new file mode 100644
index 0000000..6d0286f
--- /dev/null
+++ b/lua/lexers/icon.lua
@@ -0,0 +1,78 @@
+-- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
+-- LPeg lexer for the Icon programming language.
+-- http://www.cs.arizona.edu/icon
+-- Contributed by Carl Sturtivant.
+
+local l = require('lexer')
+local token, word_match = l.token, l.word_match
+local P, R, S = lpeg.P, lpeg.R, lpeg.S
+
+local M = {_NAME = 'icon'}
+
+-- Whitespace.
+local ws = token(l.WHITESPACE, l.space^1)
+
+--Comments
+local line_comment = '#' * l.nonnewline_esc^0
+local comment = token(l.COMMENT, line_comment)
+
+-- Strings.
+local cset = l.delimited_range("'")
+local str = l.delimited_range('"')
+local string = token(l.STRING, cset + str)
+
+-- Numbers.
+local radix_literal = P('-')^-1 * l.dec_num * S('rR') * l.alnum^1
+local number = token(l.NUMBER, radix_literal + l.float + l.integer)
+
+-- Preprocessor.
+local preproc_word = word_match{
+  'include', 'line', 'define', 'undef', 'ifdef', 'ifndef', 'else', 'endif',
+  'error'
+}
+local preproc = token(l.PREPROCESSOR, S(' \t')^0 * P('$') * preproc_word)
+
+-- Keywords.
+local keyword = token(l.KEYWORD, word_match{
+  'break', 'by', 'case', 'create', 'default', 'do', 'else', 'end', 'every',
+  'fail', 'global', 'if', 'initial', 'invocable', 'link', 'local', 'next',
+  'not', 'of', 'procedure', 'record', 'repeat', 'return', 'static', 'suspend',
+  'then', 'to', 'until', 'while'
+})
+
+-- Icon Keywords: unique to Icon; use l.TYPE, as Icon is dynamically typed
+local type = token(l.TYPE, P('&') * word_match{
+  'allocated', 'ascii', 'clock', 'collections', 'cset', 'current', 'date',
+  'dateline', 'digits', 'dump', 'e', 'error', 'errornumber', 'errortext',
+  'errorvalue', 'errout', 'fail', 'features', 'file', 'host', 'input', 'lcase',
+  'letters', 'level', 'line', 'main', 'null', 'output', 'phi', 'pi', 'pos',
+  'progname', 'random', 'regions', 'source', 'storage', 'subject', 'time',
+  'trace', 'ucase', 'version'
+})
+
+-- Identifiers.
+local identifier = token(l.IDENTIFIER, l.word)
+
+-- Operators.
+local operator = token(l.OPERATOR, S('+-/*%<>~!=^&|?~@:;,.()[]{}'))
+
+M._rules = {
+  {'whitespace', ws},
+  {'keyword', keyword},
+  {'type', type},
+  {'identifier', identifier},
+  {'comment', comment},
+  {'string', string},
+  {'number', number},
+  {'preproc', preproc},
+  {'operator', operator},
+}
+
+M._foldsymbols = {
+  _patterns = {'%l+', '#'},
+  [l.PREPROCESSOR] = {ifdef = 1, ifndef = 1, endif = -1},
+  [l.KEYWORD] = { procedure = 1, ['end'] = -1},
+  [l.COMMENT] = {['#'] = l.fold_line_comments('#')}
+}
+
+return M