Complete question from chapter 11.

1 files changed, 25 insertions, 0 deletions

diff --git a/assignments/4/tokenizer.rb b/assignments/4/tokenizer.rb
new file mode 100755
index 0000000..0bd2e2d
--- /dev/null
+++ b/assignments/4/tokenizer.rb
@@ -0,0 +1,25 @@
+#!/usr/bin/env ruby
+
+WHITESPACE = Regexp.new('[[:blank:]]+')
+SPLITTABLES = [';', '(', ')']
+
+def tokenize(code)
+  pattern = Regexp.new("[^#{Regexp.escape(SPLITTABLES.join)}]+")
+  output = []
+  tokens = code.chomp.strip.split(WHITESPACE)
+  tokens.each do |token|
+    prefix, stem, suffix = token.partition(pattern)
+    output << prefix.split('') unless prefix.empty?
+    output << stem unless stem.empty?
+    output << suffix.split('') unless suffix.empty?
+  end
+
+  output.flatten
+end
+
+
+code = ARGV[0]
+tokens = tokenize(code)
+
+puts "Input: #{code.inspect}"
+puts "Tokens: #{tokens.inspect}"