lib/text: factorize the implementations of capitalize and capitalized

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>

diff --git a/lib/core/text/abstract_text.nit b/lib/core/text/abstract_text.nit
index c9d1279..c542631 100644 (file)
--- a/lib/core/text/abstract_text.nit
+++ b/lib/core/text/abstract_text.nit
@@ -1369,21 +1369,7 @@ abstract class String
                if length == 0 then return self
 
                var buf = new Buffer.with_cap(length)
-
-               var curr = chars[0].to_upper
-               var prev = curr
-               buf[0] = curr
-
-               for i in [1 .. length[ do
-                       prev = curr
-                       curr = self[i]
-                       if prev.is_letter then
-                               buf[i] = curr.to_lower
-                       else
-                               buf[i] = curr.to_upper
-                       end
-               end
-
+               buf.capitalize(src=self)
                return buf.to_s
        end
 end
@@ -1478,6 +1464,11 @@ abstract class Buffer
        # Letters that follow a letter are lowercased
        # Letters that follow a non-letter are upcased.
        #
+       # When `src` is specified, this method reads from `src`
+       # instead of `self` but still writes the result to the beginning of `self`.
+       # This requires `self` to have the capacity to receive all of the
+       # capitalized content of `src`.
+       #
        # SEE: `Char::is_letter` for the definition of a letter.
        #
        #     var b = new FlatBuffer.from("jAVAsCriPt")
@@ -1489,14 +1480,21 @@ abstract class Buffer
        #     b = new FlatBuffer.from("ab_c -ab0c ab\nc")
        #     b.capitalize
        #     assert b == "Ab_C -Ab0C Ab\nC"
-       fun capitalize do
+       #
+       #     b = new FlatBuffer.from("12345")
+       #     b.capitalize(src="foo")
+       #     assert b == "Foo45"
+       fun capitalize(src: nullable Text) do
+               src = src or else self
+               var length = src.length
                if length == 0 then return
-               var c = self[0].to_upper
+
+               var c = src[0].to_upper
                self[0] = c
                var prev = c
                for i in [1 .. length[ do
                        prev = c
-                       c = self[i]
+                       c = src[i]
                        if prev.is_letter then
                                self[i] = c.to_lower
                        else