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Simplified the EQUAL function logic

This commit is contained in:
Mike Cifelli 2017-02-28 12:26:18 -05:00
parent d2dfe23083
commit 544df91c27
1 changed files with 0 additions and 42 deletions
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42
src/function/builtin/predicate/EQUAL.java
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@ -1,7 +1,6 @@
package function.builtin.predicate; package function.builtin.predicate;
import function.*; import function.*;
import function.builtin.cons.LIST;
import sexpression.*; import sexpression.*;
@FunctionNames({ "EQUAL" }) @FunctionNames({ "EQUAL" })
@ -17,10 +16,6 @@ public class EQUAL extends LispFunction {
public SExpression call(Cons argumentList) { public SExpression call(Cons argumentList) {
argumentValidator.validate(argumentList); argumentValidator.validate(argumentList);
return callRecursive(argumentList);
}
private SExpression callRecursive(Cons argumentList) {
Cons rest = (Cons) argumentList.getRest(); Cons rest = (Cons) argumentList.getRest();
SExpression firstArgument = argumentList.getFirst(); SExpression firstArgument = argumentList.getFirst();
SExpression secondArgument = rest.getFirst(); SExpression secondArgument = rest.getFirst();
@ -29,43 +24,6 @@ public class EQUAL extends LispFunction {
} }
private SExpression equal(SExpression firstArgument, SExpression secondArgument) { private SExpression equal(SExpression firstArgument, SExpression secondArgument) {
if (isListPair(firstArgument, secondArgument))
return listEqual(firstArgument, secondArgument);
return atomEqual(firstArgument, secondArgument);
}
private boolean isListPair(SExpression firstArgument, SExpression secondArgument) {
return firstArgument.isCons() && secondArgument.isCons();
}
private SExpression listEqual(SExpression firstArgument, SExpression secondArgument) {
Cons listOne = (Cons) firstArgument;
Cons listTwo = (Cons) secondArgument;
SExpression listOneFirst = listOne.getFirst();
SExpression listTwoFirst = listTwo.getFirst();
SExpression listOneRest = listOne.getRest();
SExpression listTwoRest = listTwo.getRest();
SExpression firstEqual = callRecursive(makeArgumentList(listOneFirst, listTwoFirst));
SExpression restEqual = callRecursive(makeArgumentList(listOneRest, listTwoRest));
return logicalConjunction(firstEqual, restEqual);
}
private Cons makeArgumentList(SExpression one, SExpression two) {
return new Cons(one, LIST.makeList(two));
}
private SExpression logicalConjunction(SExpression firstEqual, SExpression restEqual) {
return bothAreTrue(firstEqual, restEqual) ? Symbol.T : Nil.getInstance();
}
private boolean bothAreTrue(SExpression firstEqual, SExpression restEqual) {
return (firstEqual == Symbol.T) && (restEqual == Symbol.T);
}
private SExpression atomEqual(SExpression firstArgument, SExpression secondArgument) {
return isEqual(firstArgument, secondArgument) ? Symbol.T : Nil.getInstance(); return isEqual(firstArgument, secondArgument) ? Symbol.T : Nil.getInstance();
} }