Add String#upto

2 files changed, 105 insertions, 0 deletions

diff --git a/mrbgems/mruby-string-ext/mrblib/string.rb b/mrbgems/mruby-string-ext/mrblib/string.rb
index fd805b144..2b61fdb48 100644
--- a/mrbgems/mruby-string-ext/mrblib/string.rb
+++ b/mrbgems/mruby-string-ext/mrblib/string.rb
@@ -267,4 +267,47 @@ class String
     end
     return newstr.slice(0,idx)
   end
+
+  #     str.upto(other_str, exclusive=false) {|s| block }   -> str
+  #     str.upto(other_str, exclusive=false)                -> an_enumerator
+  #
+  #  Iterates through successive values, starting at <i>str</i> and
+  #  ending at <i>other_str</i> inclusive, passing each value in turn to
+  #  the block. The <code>String#succ</code> method is used to generate
+  #  each value.  If optional second argument exclusive is omitted or is false,
+  #  the last value will be included; otherwise it will be excluded.
+  #
+  #  If no block is given, an enumerator is returned instead.
+  #
+  #     "a8".upto("b6") {|s| print s, ' ' }
+  #     for s in "a8".."b6"
+  #       print s, ' '
+  #     end
+  #
+  #  <em>produces:</em>
+  #
+  #     a8 a9 b0 b1 b2 b3 b4 b5 b6
+  #     a8 a9 b0 b1 b2 b3 b4 b5 b6
+  #
+  #  If <i>str</i> and <i>other_str</i> contains only ascii numeric characters,
+  #  both are recognized as decimal numbers. In addition, the width of
+  #  string (e.g. leading zeros) is handled appropriately.
+  #
+  #     "9".upto("11").to_a   #=> ["9", "10", "11"]
+  #     "25".upto("5").to_a   #=> []
+  #     "07".upto("11").to_a  #=> ["07", "08", "09", "10", "11"]
+  #
+  def upto(other_str, excl=false, &block)
+    return to_enum :upto, other_str, excl unless block
+
+    str = self
+    n = self.<=>other_str
+    return self if n > 0 || (self == other_str && excl)
+    while true
+      block.call(str)
+      return self if !excl && str == other_str
+      str = str.succ
+      return self if excl && str == other_str
+    end
+  end
 end
diff --git a/mrbgems/mruby-string-ext/test/string.rb b/mrbgems/mruby-string-ext/test/string.rb
index 83e69859b..14e00428e 100644
--- a/mrbgems/mruby-string-ext/test/string.rb
+++ b/mrbgems/mruby-string-ext/test/string.rb
@@ -393,3 +393,65 @@ assert('String#ljust') do
   assert_equal "hello123412341234123", "hello".ljust(20, '1234')
   assert_equal "hello", "hello".ljust(-3)
 end
+
+assert('String#upto') do
+  a     = "aa"
+  start = "aa"
+  count = 0
+  assert_equal("aa", a.upto("zz") {|s|
+    assert_equal(start, s)
+    start.succ!
+    count += 1
+  })
+  assert_equal(676, count)
+
+  a     = "a"
+  start = "a"
+  count = 0
+  assert_equal("a", a.upto("a") {|s|
+    assert_equal(start, s)
+    start.succ!
+    count += 1
+  })
+  assert_equal(1, count)
+
+  a     = "a"
+  start = "a"
+  count = 0
+  assert_equal("a", a.upto("b", true) {|s|
+    assert_equal(start, s)
+    start.succ!
+    count += 1
+  })
+  assert_equal(1, count)
+
+  a     = "0"
+  start = "0"
+  count = 0
+  assert_equal("0", a.upto("0") {|s|
+    assert_equal(start, s)
+    start.succ!
+    count += 1
+  })
+  assert_equal(1, count)
+
+  a     = "0"
+  start = "0"
+  count = 0
+  assert_equal("0", a.upto("-1") {|s|
+    assert_equal(start, s)
+    start.succ!
+    count += 1
+  })
+  assert_equal(0, count)
+
+  a     = "-1"
+  start = "-1"
+  count = 0
+  assert_equal("-1", a.upto("-2") {|s|
+    assert_equal(start, s)
+    start.succ!
+    count += 1
+  })
+  assert_equal(2, count)
+end