Visual Prolog 8 throws error c504 : The expression has type '() -> ::char procedure', which is incompatible with the type '::char'.
main.pro
implement main
open core, console
class predicates
цикл : ().
print : ().
clauses
цикл().
print() :-
console::initUtf8(),
цикл,
C = readChar,
/* Читать символ и связывать его с переменной C */
write(C),
C1 = convert(char, C),
C2 = convert(char, '\r').
C1 = C2.
/* Является ли введенный символ возвратом каретки? fail, если нет */
run() :-
цикл,
fail.
run() :-
succeed.
% place your own code here
end implement main
goal
mainExe::run(main::run).
How can to fix it?
You seem to have the error here:
print() :-
....
цикл,
C = readChar, % <<-------
You should write it like this
C = readChar(),as searching for readChar in the manual reveals, where one can see the suggested usage as
_ = console::readChar().
Seem that the error message suggests the same: readChar "is a procedure of type () -> char.", not "a char". Your C is a char. To get the result from a procedure we usually need to run it (this "run" is unrelated to run in your code).