Prolog lets you specify a series of declarative logic statements (i.e. “X is an Apple”, “if X is an Apple then X is a fruit”). It can trace through all solutions to a problem. In the IDE this is done by pressing “;”. If you structure your program correctly, you can get the whole output to print to a file.<\/p>\n
\nmain :- \n\tset_prolog_flag(toplevel_print_options,\n [quoted(true)]),\n\tsubset(['A', 'A#', 'B', 'C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#'], X),\n\twrite(X),\n nl,fail;true.\nrun :- main, halt.\n<\/pre>\nThis triggers a loop by failing each output – since the result is always considered a failure, Prolog looks for the next valid result. The first line of main sets output options – this ensures that long values are not truncated with an ellipsis. The second line is your function call. “Write” displays the results to the command line, and nl adds a line break. “Fail” causes the function to be re-evaluated with the next set of parameters, but ultimately main returns “true”, so that anything that calls it can continue on. <\/p>\n
Run it like so:<\/p>\n
\nswipl -s test.pl -t run > output.txt\n<\/pre>\nThe -s argument specifies a file containing declaration statements. -t specifies a default goal to evaluate.<\/p>\n","protected":false},"excerpt":{"rendered":"
Prolog lets you specify a series of declarative logic statements (i.e. “X is an Apple”, “if X is an Apple then X is a fruit”). It can trace through all solutions to a problem. In the IDE this is done by pressing “;”. If you structure your program correctly, you can get the whole output … <\/p>\n