gsub/sub supports back references in substitutes. fixes #2816.

This implementation is compatible with CRuby's String#gsub/sub
except \1 ... \9 and \+.  They are useless without Regexp library.

1 files changed, 18 insertions, 0 deletions

diff --git a/test/t/string.rb b/test/t/string.rb
index 63e4af000..ee6fe0848 100644
--- a/test/t/string.rb
+++ b/test/t/string.rb
@@ -254,6 +254,15 @@ assert('String#gsub', '15.2.10.5.18') do
   assert_equal('A',      'a'.gsub('a'){|w| w.capitalize })
 end
 
+assert('String#gsub with backslash') do
+  s = 'abXcdXef'
+  assert_equal 'ab<\\>cd<\\>ef',    s.gsub('X', '<\\\\>')
+  assert_equal 'ab<X>cd<X>ef',      s.gsub('X', '<\\&>')
+  assert_equal 'ab<X>cd<X>ef',      s.gsub('X', '<\\0>')
+  assert_equal 'ab<ab>cd<abXcd>ef', s.gsub('X', '<\\`>')
+  assert_equal 'ab<cdXef>cd<ef>ef', s.gsub('X', '<\\\'>')
+end
+
 assert('String#gsub!', '15.2.10.5.19') do
   a = 'abcabc'
   a.gsub!('b', 'B')
@@ -416,6 +425,15 @@ assert('String#sub', '15.2.10.5.36') do
   assert_equal 'aa$', 'aa#'.sub('#', '$')
 end
 
+assert('String#sub with backslash') do
+  s = 'abXcdXef'
+  assert_equal 'ab<\\>cdXef',    s.sub('X', '<\\\\>')
+  assert_equal 'ab<X>cdXef',     s.sub('X', '<\\&>')
+  assert_equal 'ab<X>cdXef',     s.sub('X', '<\\0>')
+  assert_equal 'ab<ab>cdXef',    s.sub('X', '<\\`>')
+  assert_equal 'ab<cdXef>cdXef', s.sub('X', '<\\\'>')
+end
+
 assert('String#sub!', '15.2.10.5.37') do
   a = 'abcabc'
   a.sub!('b', 'B')