A-M baby

Task/Multisplit/Ruby/multisplit-1.rb

@@ -0,0 +1,14 @@
+text = 'a!===b=!=c'
+separators = ['==', '!=', '=']
+
+def multisplit_simple(text, separators)
+  sep_regex = Regexp.new(separators.collect {|sep| Regexp.escape(sep)}.join('|'))
+  text.split(sep_regex)
+end
+
+p multisplit_simple(text, separators)
+["a", "", "b", "", "c"]
+=> nil
+p multisplit_simple(text, ['=', '!=', '=='])
+["a", "", "", "b", "", "c"]
+=> nil

Task/Multisplit/Ruby/multisplit-2.rb

@@ -0,0 +1,18 @@
+def multisplit(text, separators)
+  sep_regex = Regexp.new(separators.collect {|sep| Regexp.escape(sep)}.join('|'))
+  separator_info = []
+  pieces = []
+  i = prev = 0
+  while i = text.index(sep_regex, i)
+    separator = Regexp.last_match(0)
+    pieces << text[prev .. i-1]
+    separator_info << [separator, i]
+    i = i + separator.length
+    prev = i
+  end
+  pieces << text[prev .. -1]
+  [pieces, separator_info]
+end
+
+p multisplit(text, separators)
+# => [["a", "", "b", "", "c"], [["!=", 1], ["==", 3], ["=", 6], ["!=", 7]]]

Task/Multisplit/Ruby/multisplit-3.rb

@@ -0,0 +1,7 @@
+def multisplit_rejoin(info)
+  str = info[0].zip(info[1])[0..-2].inject("") {|str, (piece, (sep, idx))| str << piece << sep}
+  str << info[0].last
+end
+
+p multisplit_rejoin(multisplit(text, separators)) == text
+# => true