Merge pull request #493 from obolzer/String#upto

Implement String#upto and fix String#succ

lib-topaz/string.rb

@@ -59,4 +59,32 @@ def succ
     self.dup.succ!
   end
   alias next succ
+
+  def upto(max, exclusive = false, &block)
+    raise TypeError.new("can't convert #{max.class} into String") unless max.respond_to?(:to_str)
+    raise NotImplementedError.new("Object#enum_for") unless block
+
+    maximum = max.to_str
+    return self if self > maximum
+
+    current = self.dup
+    while current <= maximum
+      break if current.length > maximum.length
+      break if exclusive and current == maximum
+      yield current
+      # special handling to use ASCII map for single letters
+      # ("9" followed by ":" not handled by String#succ)
+      if current == "9" && self.length == 1 && maximum.length == 1 then
+        current = ":"
+      elsif current == "Z" && self.length == 1 && maximum.length == 1 then
+        current = "["
+      elsif current == "z" && self.length == 1 && maximum.length == 1 then
+        current = "{"
+      else
+        current = current.succ
+      end
+    end
+
+    return self
+  end
 end

spec/tags/core/string/succ_tags.txt

@@ -1,3 +1,2 @@
-fails:String#succ increases the next best alphanumeric (jumping over non-alphanumerics) if there is a carry
 fails:String#succ returns subclass instances when called on a subclass
 fails:String#succ! raises a RuntimeError if self is frozen

spec/tags/core/string/upto_tags.txt

@@ -1,13 +1 @@
-fails:String#upto passes successive values, starting at self and ending at other_string, to the block
-fails:String#upto calls the block once even when start eqals stop
-fails:String#upto doesn't call block with self even if self is less than stop but stop length is less than self length
-fails:String#upto doesn't call block if stop is less than self and stop length is less than self length
-fails:String#upto doesn't call the block if self is greater than stop
-fails:String#upto stops iterating as soon as the current value's character count gets higher than stop's
-fails:String#upto returns self
-fails:String#upto tries to convert other to string using to_str
-fails:String#upto raises a TypeError if other can't be converted to a string
-fails:String#upto does not work with symbols
 fails:String#upto returns an enumerator when no block given
-fails:String#upto uses the ASCII map for single letters
-fails:String#upto stops before the last value if exclusive

topaz/objects/stringobject.py

@@ -261,6 +261,7 @@ def succ(self, storage):
                     storage[start] = "A"
                 else:
                     storage[start] = chr(ord(ch) + 1)
+                    carry = "\0"
 
                 if carry == "\0":
                     break
@@ -280,7 +281,7 @@ def succ(self, storage):
                     break
                 start -= 1
 
-        if start < 0:
+        if start < 0 and carry != "\0":
             last_alnum_ch = storage[last_alnum]
             storage[last_alnum] = carry
             storage.insert(last_alnum + 1, last_alnum_ch)