Add String#upto

1 files changed, 43 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