81 lines
2.2 KiB
Java
81 lines
2.2 KiB
Java
package rules;
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/*
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SETTINGS: (please don't move this part)
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PATH=ExpandRule2
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*/
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import it.cavallium.warppi.math.Function;
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import it.cavallium.warppi.math.MathContext;
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import it.cavallium.warppi.math.functions.Multiplication;
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import it.cavallium.warppi.math.functions.Sum;
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import it.cavallium.warppi.math.rules.Rule;
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import it.cavallium.warppi.math.rules.RuleType;
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import it.cavallium.warppi.util.Error;
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import it.cavallium.warppi.util.Errors;
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import it.unimi.dsi.fastutil.objects.ObjectArrayList;
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/**
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* Expand rule
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* a(b+c)=ab+ac
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*
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* @author Andrea Cavalli
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*
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*/
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public class ExpandRule2 implements Rule {
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// Rule name
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@Override
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public String getRuleName() {
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return "ExpandRule2";
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}
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// Rule type
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@Override
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public RuleType getRuleType() {
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return RuleType.EXPANSION;
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}
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/* Rule function
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Returns:
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- null if it's not executable on the function "f"
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- An ObjectArrayList<Function> if it did something
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*/
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@Override
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public ObjectArrayList<Function> execute(final Function f) throws Error {
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boolean isExecutable = false;
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if (f instanceof Multiplication) {
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final Multiplication fnc = (Multiplication) f;
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if (fnc.getParameter1() instanceof Sum)
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isExecutable = true;
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else if (fnc.getParameter2() instanceof Sum)
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isExecutable = true;
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else
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isExecutable = false;
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}
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if (isExecutable) {
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final ObjectArrayList<Function> result = new ObjectArrayList<>();
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final MathContext root = f.getMathContext();
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final Multiplication fnc = (Multiplication) f;
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final Sum sum;
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final Function a;
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if (fnc.getParameter1() instanceof Sum) {
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sum = (Sum) fnc.getParameter1();
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a = fnc.getParameter2();
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} else if (fnc.getParameter2() instanceof Sum) {
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sum = (Sum) fnc.getParameter2();
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a = fnc.getParameter1();
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} else
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throw new Error(Errors.UNBALANCED_STACK);
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final Function b = sum.getParameter1();
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final Function c = sum.getParameter2();
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final Multiplication ab = new Multiplication(root, a, b);
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final Multiplication ac = new Multiplication(root, a, c);
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result.add(new Sum(root, ab, ac));
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return result;
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} else
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return null;
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}
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}
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