1 files changed, 57 insertions, 0 deletions
diff --git a/lexlua/apl.lua b/lexlua/apl.lua
new file mode 100644
index 000000000..5275ebffa
--- /dev/null
+++ b/lexlua/apl.lua
@@ -0,0 +1,57 @@
+-- Copyright 2015-2018 David B. Lamkins <david@lamkins.net>. See License.txt.
+-- APL 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('apl')
+
+-- Whitespace.
+lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))
+
+-- Comments.
+lex:add_rule('comment', token(lexer.COMMENT, (P('⍝') + '#') *
+                                             lexer.nonnewline^0))
+
+-- Strings.
+local sq_str = lexer.delimited_range("'", false, true)
+local dq_str = lexer.delimited_range('"')
+lex:add_rule('string', token(lexer.STRING, sq_str + dq_str))
+
+-- Numbers.
+local dig = R('09')
+local rad = P('.')
+local exp = S('eE')
+local img = S('jJ')
+local sgn = P('¯')^-1
+local float = sgn * (dig^0 * rad * dig^1 + dig^1 * rad * dig^0 + dig^1) *
+              (exp * sgn *dig^1)^-1
+lex:add_rule('number', token(lexer.NUMBER, float * img * float + float))
+
+-- Keywords.
+lex:add_rule('keyword', token(lexer.KEYWORD, P('⍞') + 'χ' + '⍺' + '⍶' + '⍵' +
+                                             '⍹' + '⎕' * R('AZ', 'az')^0))
+
+-- Names.
+local n1l = R('AZ', 'az')
+local n1b = P('_') + '∆' + '⍙'
+local n2l = n1l + R('09')
+local n2b = n1b + '¯'
+local n1 = n1l + n1b
+local n2 = n2l + n2b
+local name = n1 * n2^0
+
+-- Labels.
+lex:add_rule('label', token(lexer.LABEL, name * ':'))
+
+-- Variables.
+lex:add_rule('variable', token(lexer.VARIABLE, name))
+
+-- Special.
+lex:add_rule('special', token(lexer.TYPE, S('{}[]();') + '←' + '→' + '◊'))
+
+-- Nabla.
+lex:add_rule('nabla', token(lexer.PREPROCESSOR, P('∇') + '⍫'))
+
+return lex