Prolog：要列出的字符串

Question

I have a string that I want to convert to a list:

"a + b = c"

I need it in list format to pass it onto to a member rule. When I pass it onto the member rule directly, it passes as a series of numbers which I assume is their character code, but I want the actual characters instead. How do I make it into a list then use it with a rule. I'm a novice in Prolog so I would appreciate any help.

Answer 1

SWI-Prolog has string_chars/2, but you can obtain the same using 2 ISO conforming predicates

?- atom_codes(A, "a + b = c"), atom_chars(A, Cs).
A = 'a + b = c',
Cs = [a, ' ', +, ' ', b, ' ', =, ' ', c].