map-charset-chars

map-charset-chars is a built-in function in `C source code'.

(map-charset-chars FUNCTION CHARSET &optional ARG FROM-CODE TO-CODE)

Call FUNCTION for all characters in CHARSET.
FUNCTION is called with an argument RANGE and the optional 3rd
argument ARG.

RANGE is a cons (FROM . TO), where FROM and TO indicate a range of
characters contained in CHARSET.

The optional 4th and 5th arguments FROM-CODE and TO-CODE specify the
range of code points (in CHARSET) of target characters.