gnu-prolog

问题 So basically it seems that GNU Prolog use 28bit integer on my 32bit x86 Linux. The code below can not be compiled: foo(A) :- A0 is 0xdeadbeef, A1 is A0 >> 8, A2 is A0 >> 16, A3 is A0 >> 24. Then I am confused with two typical situations below: How to represent a 32bit integer in GNU Prolog (like 0xdeadbeef)? and pushing it further, how to represent a 64 bit integer ? On 64 bit x86 Linux, long long type in C has 64 bit. When using GNU Prolog to call C, the interface defined in the manual has

问题 So basically it seems that GNU Prolog use 28bit integer on my 32bit x86 Linux. The code below can not be compiled: foo(A) :- A0 is 0xdeadbeef, A1 is A0 >> 8, A2 is A0 >> 16, A3 is A0 >> 24. Then I am confused with two typical situations below: How to represent a 32bit integer in GNU Prolog (like 0xdeadbeef)? and pushing it further, how to represent a 64 bit integer ? On 64 bit x86 Linux, long long type in C has 64 bit. When using GNU Prolog to call C, the interface defined in the manual has

问题 So basically it seems that GNU Prolog use 28bit integer on my 32bit x86 Linux. The code below can not be compiled: foo(A) :- A0 is 0xdeadbeef, A1 is A0 >> 8, A2 is A0 >> 16, A3 is A0 >> 24. Then I am confused with two typical situations below: How to represent a 32bit integer in GNU Prolog (like 0xdeadbeef)? and pushing it further, how to represent a 64 bit integer ? On 64 bit x86 Linux, long long type in C has 64 bit. When using GNU Prolog to call C, the interface defined in the manual has

问题 Let's define custom operators - let it be ++ , equals :- op(900, yfx, equals). :- op(800, xfy, ++). And fact: check(A equals A). I try to make predicate, let it be check/1 , that will return true in all following situations: check( a ++ b ++ c ++ d equals c ++ d ++ b ++ a ), check( a ++ b ++ c ++ d equals d ++ a ++ c ++ b), check( a ++ b ++ c ++ d equals d ++ b ++ c ++ a ), % and all permutations... of any amount of atoms check( a ++ ( b ++ c ) equals (c ++ a) ++ b), % be resistant to any

问题 I am new to Prolog, but I am stuck at this supposedly simple command. I have loaded a knowledge base with no errors, and whenever I try do assert (and even help ) I get the following message: uncaught exception: error(existence_error(procedure,assert/1),top_level/0) {2} What am I exactly missing? Appreciated. 回答1: Use assertz/1 or asserta/1 instead. GNU-Prolog does not provide assert/1 because only asserta/1 and assertz/1 are defined in the standard. Note that while asserta/1 always had one

问题 I'm trying to write a prolog program that determines whether one list is a permutation of another. Input is of the form perm(L,M) , which will be true if and only if list L is a permutation of list M . This is for my AI class, so I cannot just use the nifty little permutation predicate that gprolog already provides. Our professor noted that the member predicate might be useful, but any ideas I have that involve it seem to require very tricky and not-so-declarative things (and I'm assuming

问题 I'm reading "Seven languages in seven weeks" atm, and I'm stumped over some Prolog query that I don't understand the 'no' response to. The friends.pl file looks like this: likes(wallace, cheese). likes(grommit, cheese). likes(wendolene, sheep). friend(X, Y) :- \+(X = Y), likes(X, Z), likes(Y, Z). I can do some trivial queries on it, such as: | ?- ['friends']. compiling /home/marc/btlang-code/code/prolog/friends.pl for byte code... /home/marc/btlang-code/code/prolog/friends.pl compiled, 12

问题 Basically I am trying to simulate C pointer dereference using gnu-prolog. Here is the code: Prolog :-foreign(fun(+integer,-integer)). % p = &b; testfun(Var, Val) :- fun(Val, Var). main :- A is 1, testfun(A, P), write(P), C: #include <gprolog.h> #include <string.h> PlBool fun(int ptr, int* res){ *res = &ptr; // this is wrong if(res==NULL){ return PL_FALSE; }else{ return PL_TRUE; } } So basically it is wrong, because ptr is just a temp variable on the stack, and its memory will be deallocated

问题 I am trying to use read_line_to_codes(Stream,Result) and atom_codes(String,Result) . These two predicates first, read line from file as an array of char codes, and then convert this array back to string. Then I would like to input all those strings to an array of Strings. I tried the recursive approach but have trouble with how to actually instantiate the array to empty in the beginning, and what would be the terminating condition of process_the_stream/2 . /*The code which doesn't work.. but

问题 I feel like I'm bashing my head against a wall with something that I assume should be easy. Perhaps my approach is incorrect. I definitely don't feel like I understand the concept behind I/O in Prolog. (Such as: what is the difference between a stream alias and the variable bound by open/3?) But I digress: How do a read a file line-by-line in GNU Prolog? (So without access to the handy functions that SWI has.) I assume it has something to do with get_char/1 and peek_char/1 (to check for a