EffOperations

src/main/java/ch/njol/skript/effects/EffOperations.java

@@ -0,0 +1,247 @@
+package ch.njol.skript.effects;
+
+import ch.njol.skript.Skript;
+import ch.njol.skript.classes.Changer.ChangeMode;
+import ch.njol.skript.classes.Changer.ChangerUtils;
+import ch.njol.skript.config.Node;
+import ch.njol.skript.doc.Description;
+import ch.njol.skript.doc.Example;
+import ch.njol.skript.doc.Name;
+import ch.njol.skript.doc.Since;
+import ch.njol.skript.expressions.arithmetic.ExprArithmetic;
+import ch.njol.skript.lang.Effect;
+import ch.njol.skript.lang.Expression;
+import ch.njol.skript.lang.SkriptParser.ParseResult;
+import ch.njol.skript.lang.SyntaxStringBuilder;
+import ch.njol.skript.registrations.Classes;
+import ch.njol.skript.util.LiteralUtils;
+import ch.njol.skript.util.Patterns;
+import ch.njol.util.Kleenean;
+import org.bukkit.event.Event;
+import org.jetbrains.annotations.Nullable;
+import org.skriptlang.skript.lang.arithmetic.Arithmetics;
+import org.skriptlang.skript.lang.arithmetic.Operation;
+import org.skriptlang.skript.lang.arithmetic.OperationInfo;
+import org.skriptlang.skript.lang.arithmetic.Operator;
+import org.skriptlang.skript.log.runtime.SyntaxRuntimeErrorProducer;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.Function;
+
+@Name("Operations")
+@Description("Perform multiplication, division, or exponentiation operations on variable objects "
+	+ "(i.e. numbers, vectors, timespans, and other objects from addons). "
+	+ "Literals cannot be used on the left-hand side.")
+@Example("""
+	set {_num} to 1
+	multiply {_num} by 10
+	divide {_num} by 5
+	raise {_num} to the power of 2
+	""")
+@Example("""
+	set {_nums::*} to 15, 21 and 30
+	divide {_nums::*} by 3
+	multiply {_nums::*} by 5
+	raise {_nums::*} to the power of 3
+	""")
+@Example("""
+	set {_vector} to vector(1,1,1)
+	multiply {_vector} by vector(4,8,16)
+	divide {_vector} by 2
+	""")
+@Example("""
+	set {_timespan} to 1 hour
+	multiply {_timespan} by 3
+	""")
+@Example("""
+	# Will error due to literal
+	multiply 1 by 2
+	divide 10 by {_num}
+	""")
+@Since("INSERT VERSION")
+public class EffOperations extends Effect implements SyntaxRuntimeErrorProducer {
+
+	private static final Patterns<Operator> PATTERNS = new Patterns<>(new Object[][]{
+		{"multiply %~objects% by %object%", Operator.MULTIPLICATION},
+		{"divide %~objects% by %object%", Operator.DIVISION},
+		{"raise %~objects% to [the] (power|exponent) [of] %object%", Operator.EXPONENTIATION}
+	});
+
+	static {
+		Skript.registerEffect(EffOperations.class, PATTERNS.getPatterns());
+	}
+
+	private Operator operator;
+	private Expression<?> left;
+	private Class<?>[] leftAccepts;
+	private Expression<?> right;
+	private Node node;
+	private Operation<Object, Object, Object> operation = null;
+	private OperationInfo<?, ?, ?> operationInfo;
+
+	@Override
+	public boolean init(Expression<?>[] exprs, int matchedPattern, Kleenean isDelayed, ParseResult parseResult) {
+		operator = PATTERNS.getInfo(matchedPattern);
+		node = getParser().getNode();
+		left = exprs[0];
+		right = LiteralUtils.defendExpression(exprs[1]);
+
+		leftAccepts = left.acceptChange(ChangeMode.SET);
+		// Ensure 'left' is changeable
+		if (leftAccepts == null) {
+			Skript.error("'" + left + "' cannot be set to anything and therefore cannot be " + getOperatorVerb() + ".");
+			return false;
+		} else if (leftAccepts.length == 0) {
+			throw new IllegalStateException("An expression should never return an empty array for a ChangeMode of 'SET'");
+		}
+		// Ensure the accepted classes of 'left' are non-array classes
+		for (int i = 0; i < leftAccepts.length; i++) {
+			if (leftAccepts[i].isArray()) {
+				leftAccepts[i] = leftAccepts[i].getComponentType();
+			}
+		}
+
+		Class<?> leftType = left.getReturnType();
+		Class<?> rightType = right.getReturnType();
+
+		if (leftType.equals(Object.class) && rightType.equals(Object.class)) {
+			// 'left' and 'right' return 'Object.class' thus making operation checks non-applicable
+			// However, we can check to make sure any of the registered operations return types are applicable
+			// 		for 'left's acceptedClasses
+			Class<?>[] allReturnTypes = Arithmetics.getAllReturnTypes(operator).toArray(Class[]::new);
+			if (!ChangerUtils.acceptsChangeTypes(leftAccepts, allReturnTypes)) {
+				Skript.error(left.toString(null, Skript.debug()) + " cannot be " + getOperatorVerb() + ".");
+				return false;
+			}
+			return LiteralUtils.canInitSafely(right);
+		} else if (leftType.equals(Object.class) || rightType.equals(Object.class)) {
+			// Only one returns 'Object.class'
+			Class<?>[] returnTypes;
+			if (leftType.equals(Object.class)) {
+				// 'left' returns 'Object.class', so we get all operations where 'right' is assignable to the right side
+				// of the operations and store the return types
+				returnTypes = Arithmetics.getOperations(operator).stream()
+					.filter(info -> info.getRight().isAssignableFrom(rightType))
+					.map(OperationInfo::getReturnType)
+					.toArray(Class[]::new);
+			} else {
+				// 'right' returns 'Object.class', so we get all operations where 'left' is assignable to the left side
+				// of the operations and store the return types
+				returnTypes = Arithmetics.getOperations(operator, leftType).stream()
+					.map(OperationInfo::getReturnType)
+					.toArray(Class[]::new);
+			}
+
+			// No operations found, meaning nothing can be done
+			if (returnTypes.length == 0) {
+				noOperationError(left, leftType, rightType);
+				return false;
+			}
+			// Check if 'left' can be changed into at least one of the possible return types
+			if (!ChangerUtils.acceptsChangeTypes(leftAccepts, returnTypes)) {
+				genericParseError(left, rightType);
+				return false;
+			}
+		} else {
+			// Both 'left' and 'right' return an exact class type, so we check if the operation exists
+			// Then if 'left' accepts the return type of the operation
+			operationInfo = Arithmetics.lookupOperationInfo(operator, leftType, rightType, leftAccepts);
+			if (operationInfo == null || !ChangerUtils.acceptsChangeTypes(leftAccepts, operationInfo.getReturnType())) {
+				genericParseError(left, rightType);
+				return false;
+			}
+		}
+		return LiteralUtils.canInitSafely(right);
+	}
+
+	@Override
+	protected void execute(Event event) {
+		Object rightObject = right.getSingle(event);
+		if (rightObject == null) {
+			error("Cannot operate with a null object.");
+			return;
+		}
+		if (left.isSingle() && left.getSingle(event) == null) {
+			error("Cannot operate on a null object.");
+			return;
+		}
+
+		Class<?> rightType = rightObject.getClass();
+
+		Map<Class<?>, Operation<Object, Object, ?>> cachedOperations = new HashMap<>();
+		Set<Class<?>> invalidTypes = new HashSet<>();
+
+		Function<?, ?> changerFunction = (leftInput) -> {
+			Class<?> leftType = leftInput.getClass();
+			if (invalidTypes.contains(leftType)) {
+				printArithmeticError(leftType, rightType);
+				return leftInput;
+			}
+			Operation<Object, Object, ?> operation = cachedOperations.get(leftType);
+			if (operation == null) {
+				//noinspection unchecked
+				OperationInfo<Object, Object, ?> operationInfo = (OperationInfo<Object, Object, ?>) Arithmetics.lookupOperationInfo(operator, leftType, rightType, leftAccepts);
+				if (operationInfo == null) {
+					printArithmeticError(leftType, rightType);
+					invalidTypes.add(leftType);
+					return leftInput;
+				}
+				operation = operationInfo.getOperation();
+				cachedOperations.put(leftType, operation);
+			}
+			return operation.calculate(leftInput, rightObject);
+		};
+		//noinspection unchecked,rawtypes
+		left.changeInPlace(event, (Function) changerFunction);
+	}
+
+	@Override
+	public Node getNode() {
+		return node;
+	}
+
+	private void printArithmeticError(Class<?> left, Class<?> right) {
+		String error = ExprArithmetic.getArithmeticErrorMessage(operator, left, right);
+		if (error != null)
+			error(error);
+	}
+
+	private void genericParseError(Expression<?> leftExpr, Class<?> rightType) {
+		Skript.error("'" + leftExpr + "' cannot be " + getOperatorVerb() + " by "
+			+ Classes.getSuperClassInfo(rightType).getName().withIndefiniteArticle() + ".");
+	}
+
+	private void noOperationError(Expression<?> leftExpr, Class<?> leftType, Class<?> rightType) {
+		String error = ExprArithmetic.getArithmeticErrorMessage(operator, leftType, rightType);
+		if (error != null) {
+			Skript.error(error);
+		} else {
+			genericParseError(leftExpr, rightType);
+		}
+	}
+
+	private String getOperatorVerb() {
+		return switch (operator) {
+			case MULTIPLICATION -> "multiplied";
+			case DIVISION -> "divided";
+			case EXPONENTIATION -> "exponentiated";
+			default -> "";
+		};
+	}
+
+	@Override
+	public String toString(@Nullable Event event, boolean debug) {
+		SyntaxStringBuilder builder = new SyntaxStringBuilder(event, debug);
+		switch (operator) {
+			case MULTIPLICATION -> builder.append("multiply", left, "by");
+			case DIVISION -> builder.append("divide", left, "by");
+			case EXPONENTIATION -> builder.append("raise", left, "to the power of");
+		}
+		builder.append(right);
+		return builder.toString();
+	}
+
+}

src/main/java/ch/njol/skript/expressions/arithmetic/ExprArithmetic.java

@@ -304,12 +304,29 @@ protected T[] get(Event event) {
 	}
 
 	private boolean error(Class<?> firstClass, Class<?> secondClass) {
-		ClassInfo<?> first = Classes.getSuperClassInfo(firstClass), second = Classes.getSuperClassInfo(secondClass);
-		if (first.getC() != Object.class && second.getC() != Object.class) // errors with "object" are not very useful and often misleading
-			Skript.error(operator.getName() + " can't be performed on " + first.getName().withIndefiniteArticle() + " and " + second.getName().withIndefiniteArticle());
+		String error = getArithmeticErrorMessage(operator, firstClass, secondClass);
+		if (error != null)
+			Skript.error(error);
 		return false;
 	}
 
+	/**
+	 * Get an error message in format of "'operator' cant be performed on 'left' and 'right'".
+	 * @param operator The {@link Operator} that was attempted operate
+	 * @param left The left {@link Class} attempted to be operated on
+	 * @param right The right {@link Class} attempted to be operated with
+	 * @return The {@link String} error message
+	 */
+	public static @Nullable String getArithmeticErrorMessage(Operator operator, Class<?> left, Class<?> right) {
+		ClassInfo<?> first = Classes.getSuperClassInfo(left);
+		ClassInfo<?> second = Classes.getSuperClassInfo(right);
+		if (!first.getC().equals(Object.class) && !second.getC().equals(Object.class)) {
+			return operator.getName() + " can't be performed on " + first.getName().withIndefiniteArticle() + " and "
+				+ second.getName().withIndefiniteArticle();
+		}
+		return null;
+	}
+
 	@Override
 	public Class<? extends T> getReturnType() {
 		return returnType;

src/main/java/org/skriptlang/skript/lang/arithmetic/Arithmetics.java

@@ -129,6 +129,35 @@ public static <L, R, T> OperationInfo<L, R, T> lookupOperationInfo(Operator oper
 		return info != null ? info.getConverted(leftClass, rightClass, returnType) : null;
 	}
 
+	/**
+	 * Lookup an {@link OperationInfo} that uses the provided args {@code operator}, {@code leftClass} and {@code rightClass},
+	 * and is one of the {@code possibleReturnTypes}
+	 * @param operator The {@link Operator} to be used
+	 * @param leftClass The {@link Class} to be operated on
+	 * @param rightClass The {@link Class} to be operated with
+	 * @param possibleReturnTypes The accepted return type {@link Class}es
+	 */
+	public static <L, R> @Nullable OperationInfo<L, R, ?> lookupOperationInfo(
+		Operator operator,
+		Class<L> leftClass,
+		Class<R> rightClass,
+		Class<?>... possibleReturnTypes
+	) {
+		OperationInfo<L, R, ?> info = lookupOperationInfo(operator, leftClass, rightClass);
+		if (info == null)
+			return null;
+		for (Class<?> returnType : possibleReturnTypes) {
+			if (info.getReturnType().equals(returnType))
+				return info;
+		}
+		for (Class<?> returnType : possibleReturnTypes) {
+			OperationInfo<L, R, ?> convertedInfo = info.getConverted(leftClass, rightClass, returnType);
+			if (convertedInfo != null)
+				return convertedInfo;
+		}
+		return null;
+	}
+
 	@Nullable
 	@SuppressWarnings("unchecked")
 	public static <L, R> OperationInfo<L, R, ?> lookupOperationInfo(Operator operator, Class<L> leftClass, Class<R> rightClass) {