Merge pull request #1163 from meh/regex-escape

Support extended syntax in Regex.escape

Author: José Valim

lib/elixir/lib/regex.ex

@@ -291,9 +291,20 @@ defmodule Regex do
     :re.replace(string, compiled, replacement, opts)
   end
 
-  { :ok, pattern } = :re.compile(%B"[.^$*+?()[{\\\\|]")
+  { :ok, pattern } = :re.compile(%B"[.^$*+?()[{\\\|\s#]", [:unicode])
   @escape_pattern pattern
 
+  @doc %B"""
+  Escapes a string to be literally matched in a regex.
+
+  ## Examples
+
+      iex> Regex.escape(".")
+      "\\."
+      iex> Regex.escape("\\what if")
+      "\\\\what\\ if"
+
+  """
   @spec escape(String.t | char_list) :: String.t | char_list
   def escape(string) do
     :re.replace(string, @escape_pattern, "\\\\&", [:global, { :return, return_for(string) }])

lib/elixir/test/elixir/regex_test.exs

@@ -129,24 +129,35 @@ defmodule Regex.BinaryTest do
   end
 
   test :escape do
-    assert escaping(".", ".")
-    refute escaping(".", "x")
+    assert matches_escaped?(".")
+    refute matches_escaped?(".", "x")
 
-    assert escaping("[\w]", "[\w]")
-    refute escaping("[\w]", "x")
+    assert matches_escaped?("[\w]")
+    refute matches_escaped?("[\w]", "x")
 
-    assert escaping("\\", "\\")
+    assert matches_escaped?("\\")
 
-    assert escaping("\\xff", "\\xff")
-    refute escaping("\\xff", "\xff")
+    assert matches_escaped?("\\xff", "\\xff")
+    refute matches_escaped?("\\xff", "\xff")
 
-    assert escaping("(", "(")
-    assert escaping("()", "()")
-    assert escaping("(?:foo)", "(?:foo)")
+    assert matches_escaped?("(")
+    assert matches_escaped?("()")
+    assert matches_escaped?("(?:foo)")
+
+    assert matches_escaped?("\\A  \\z")
+    assert matches_escaped?("  x  ")
+    assert matches_escaped?("  x    x ") # unicode spaces here
+    assert matches_escaped?("# lol")
+
+    assert matches_escaped?("\\A.^$*+?()[{\\| \t\n\xff\\z #hello\x{202F}\x{205F}")
+  end
+
+  defp matches_escaped?(string) do
+    matches_escaped?(string, string)
   end
 
-  defp escaping(string, match) do
-    Regex.match? %r/#{Regex.escape(string)}/, match
+  defp matches_escaped?(string, match) do
+    Regex.match? %r/#{Regex.escape(string)}/usimx, match
   end
 end