Mercury-Language/mercury — pull request #17 by sebgod (2014-12-22 06:22:40+00:00)
Title: Add is_(leading|trailing)_surrogate/1 to char

For input validation and character encoding transformations
it is essential to check for surrogate characters and their correct
sequence.

NEWS:
Announce the addition of is_(leading|trailing)_surrogate/1.

library/char.m:
Add is_leading_surrogate/1 which succeeds if a character is a
leading surrogate character.
is_trailing_surrogate/1 succeeds if the character is a
trailing surrogate character.