Prolog: Finding the Nth Element in a List
- by Thomas
I am attempting to locate the nth element of a List in Prolog. Here is the code I am attempting to use:
Cells = [OK, _, _, _, _, _] .
...
next_safe(_) :-
facing(CurrentDirection),
delta(CurrentDirection, Delta),
in_cell(OldLoc),
NewLoc is OldLoc + Delta,
nth1(NewLoc, Cells, SafetyIdentifier),
SafetyIdentifier = OK .
Basically, I am trying to check to see if a given cell is "OK" to move into. Am I missing something?