ctypes.pl -- Character code classification

This file implements the functionality of the corresponding Quintus library based on SWI-Prolog's code_type/2 predicate. Please check the documentation of this predicate to find the definitions of the classes.

See also

- code_type/2

- char_type/2

 is_paren(?Open, ?Close) is semidet

True if Open is the open-parenthesis of Close.

 to_lower(+U, -L) is det

Downcase a character code. If U is the character code of an uppercase character, unify L with the character code of the lowercase version. Else unify L with U.

 to_upper(+L, -U) is det

Upcase a character code. If L is the character code of a lowercase character, unify L with the character code of the uppercase version. Else unify U with L.

 upper_lower(?U, ?L) is det

True when U is the character code of an uppercase character and L is the character code of the corresponding lowercase character.

 is_digit(+C, +Base, -Weight) is det

is_digit(-C, +Base, +Weight) is det

Succeeds if `C' is a digit using `Base' as base and `Weight' represents its value. Only the base-10 case is handled by code_type.

Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

 is_space(Arg1)

 is_upper(Arg1)

 is_white(Arg1)

 is_period(Arg1)

 is_print(Arg1)

 is_punct(Arg1)

 is_quote(Arg1)

 is_lower(Arg1)

 is_newline(Arg1)

 is_newpage(Arg1)

 is_endfile(Arg1)

 is_endline(Arg1)

 is_cntrl(Arg1)

 is_csym(Arg1)

 is_csymf(Arg1)

 is_digit(Arg1)

 is_graph(Arg1)

 is_alnum(Arg1)

 is_alpha(Arg1)

 is_ascii(Arg1)