X-Git-Url: http://nitlanguage.org

diff --git a/lib/core/text/native.nit b/lib/core/text/native.nit
index 11c8d34..4028ea0 100644
--- a/lib/core/text/native.nit
+++ b/lib/core/text/native.nit
@@ -16,7 +16,7 @@ import math
 
 redef class Byte
 	# Gives the length of the UTF-8 char starting with `self`
-	private fun u8len: Int do
+	fun u8len: Int do
 		if self & 0b1000_0000u8 == 0u8 then
 			return 1
 		else if self & 0b1110_0000u8 == 0b1100_0000u8 then
@@ -130,7 +130,7 @@ extern class NativeString `{ char* `}
 		return ns_i
 	end
 
-	# Gets the byte index of char at position `n` in UTF-8 String
+	# Gets the char index of byte at position `n` in a UTF-8 String
 	#
 	# `char_from` and `byte_from` are cached values to seek from.
 	#
@@ -173,4 +173,16 @@ extern class NativeString `{ char* `}
 		if length_of_char_at(stpos) >= (endpos - stpos + 1) then return pos
 		return endpos
 	end
+
+	# Number of UTF-8 characters in `self` between positions `from` and `to`
+	fun utf8_length(from, to: Int): Int do
+		var st = from
+		var lst = to
+		var ln = 0
+		while st <= lst do
+			st += length_of_char_at(st)
+			ln += 1
+		end
+		return ln
+	end
 end