lib: Added `is_surrogate` service to `Char`

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>

diff --git a/lib/core/text/abstract_text.nit b/lib/core/text/abstract_text.nit
index 32628cd..17e4a23 100644 (file)
--- a/lib/core/text/abstract_text.nit
+++ b/lib/core/text/abstract_text.nit
@@ -1600,6 +1600,12 @@ redef class Char
        #     assert 'ま'.bytes == [0xE3u8, 0x81u8, 0xBEu8]
        fun bytes: SequenceRead[Byte] do return to_s.bytes
 
+       # Is `self` an UTF-16 surrogate pair ?
+       fun is_surrogate: Bool do
+               var cp = code_point
+               return cp >= 0xD800 and cp <= 0xDFFF
+       end
+
        # Length of `self` in a UTF-8 String
        private fun u8char_len: Int do
                var c = self.code_point