Add operator parameter

src/main/java/org/spongepowered/api/command/parameter/Parameter.java

@@ -42,6 +42,7 @@ import org.spongepowered.api.command.parameter.managed.ValueParameter;
 import org.spongepowered.api.command.parameter.managed.ValueParameterModifier;
 import org.spongepowered.api.command.parameter.managed.ValueParser;
 import org.spongepowered.api.command.parameter.managed.ValueUsage;
+import org.spongepowered.api.command.parameter.managed.operator.Operator;
 import org.spongepowered.api.command.parameter.managed.standard.ResourceKeyedValueParameters;
 import org.spongepowered.api.command.parameter.managed.standard.VariableValueParameters;
 import org.spongepowered.api.data.persistence.DataContainer;
@@ -519,6 +520,16 @@ public interface Parameter {
         return Parameter.builder(Long.class, ResourceKeyedValueParameters.LONG);
     }
 
+    /**
+     * Creates a builder that has the {@link ValueParameter} set to
+     * {@link ResourceKeyedValueParameters#OPERATOR}.
+     *
+     * @return A {@link Parameter.Value.Builder}
+     */
+    static Parameter.Value.Builder<Operator> operator() {
+        return Parameter.builder(Operator.class, ResourceKeyedValueParameters.OPERATOR);
+    }
+
     /**
      * Creates a builder that has the {@link ValueParameter} set to
      * {@link ResourceKeyedValueParameters#PLAYER}.

src/main/java/org/spongepowered/api/command/parameter/managed/operator/Operator.java

@@ -0,0 +1,79 @@
+/*
+ * This file is part of SpongeAPI, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) SpongePowered <https://www.spongepowered.org>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package org.spongepowered.api.command.parameter.managed.operator;
+
+import org.spongepowered.api.command.parameter.managed.standard.ResourceKeyedValueParameters;
+import org.spongepowered.api.util.annotation.CatalogedBy;
+
+/**
+ * Represents an operator that can be specified in a command.
+ *
+ * @see ResourceKeyedValueParameters#OPERATOR
+ */
+@CatalogedBy(Operators.class)
+public interface Operator {
+
+    /**
+     * The string representation of this operator
+     *
+     * @return The representation
+     */
+    String asString();
+
+    /**
+     * An operator that can operate on two numbers and return a number.
+     */
+    interface Simple extends Operator {
+
+        /**
+         * Operates on two numbers, returning the result of the operation.
+         *
+         * @param first the first number to operate on
+         * @param second the second number to operate on
+         * @return the result of the operation
+         */
+        int apply(int first, int second);
+
+        /**
+         * Operates on two numbers, returning the result of the operation.
+         *
+         * @param first the first number to operate on
+         * @param second the second number to operate on
+         * @return the result of the operation
+         */
+        long apply(long first, long second);
+
+        /**
+         * Operates on two numbers, returning the result of the operation.
+         *
+         * @param first the first number to operate on
+         * @param second the second number to operate on
+         * @return the result of the operation
+         */
+        double apply(double first, double second);
+
+    }
+
+}

src/main/java/org/spongepowered/api/command/parameter/managed/operator/Operators.java

@@ -0,0 +1,94 @@
+/*
+ * This file is part of SpongeAPI, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) SpongePowered <https://www.spongepowered.org>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package org.spongepowered.api.command.parameter.managed.operator;
+
+import org.spongepowered.api.ResourceKey;
+import org.spongepowered.api.Sponge;
+import org.spongepowered.api.registry.DefaultedRegistryReference;
+import org.spongepowered.api.registry.RegistryKey;
+import org.spongepowered.api.registry.RegistryTypes;
+
+public final class Operators {
+
+    // @formatter:off
+
+    // SORTFIELDS:ON
+
+    /**
+     * Represents the addition operation, +=
+     */
+    public static final DefaultedRegistryReference<Operator.Simple> ADDITION = Operators.key(ResourceKey.sponge("addition"));
+
+    /**
+     * Represents the assignment operation, =
+     */
+    public static final DefaultedRegistryReference<Operator> ASSIGN = Operators.key(ResourceKey.sponge("assign"));
+
+    /**
+     * Represents the division operation, /=
+     */
+    public static final DefaultedRegistryReference<Operator.Simple> DIVISION = Operators.key(ResourceKey.sponge("division"));
+
+    /**
+     * Represents the max operation, &gt;
+     */
+    public static final DefaultedRegistryReference<Operator.Simple> MAX = Operators.key(ResourceKey.sponge("max"));
+
+    /**
+     * Represents the min operation, &lt;
+     */
+    public static final DefaultedRegistryReference<Operator.Simple> MIN = Operators.key(ResourceKey.sponge("min"));
+
+    /**
+     * Represents the modulus operation, %=
+     */
+    public static final DefaultedRegistryReference<Operator.Simple> MODULUS = Operators.key(ResourceKey.sponge("modulus"));
+
+    /**
+     * Represents the multiplication operation, *=
+     */
+    public static final DefaultedRegistryReference<Operator.Simple> MULTIPLICATION = Operators.key(ResourceKey.sponge("multiplication"));
+
+    /**
+     * Represents the subtraction operation, -=
+     */
+    public static final DefaultedRegistryReference<Operator.Simple> SUBTRACTION = Operators.key(ResourceKey.sponge("subtraction"));
+
+    /**
+     * Represents the swap operation, &gt;&lt;
+     */
+    public static final DefaultedRegistryReference<Operator> SWAP = Operators.key(ResourceKey.sponge("swap"));
+
+    // SORTFIELDS:OFF
+
+    private Operators() {
+    }
+
+    private static <T extends Operator> DefaultedRegistryReference<T> key(final ResourceKey location) {
+        return RegistryKey.of(RegistryTypes.OPERATOR, location).asDefaultedReference(() -> Sponge.game().registries());
+    }
+
+    // @formatter:off
+}

src/main/java/org/spongepowered/api/command/parameter/managed/standard/ResourceKeyedValueParameters.java

@@ -28,6 +28,8 @@ import net.kyori.adventure.text.Component;
 import org.spongepowered.api.ResourceKey;
 import org.spongepowered.api.Sponge;
 import org.spongepowered.api.block.BlockState;
+import org.spongepowered.api.command.parameter.managed.operator.Operator;
+import org.spongepowered.api.command.parameter.managed.operator.Operators;
 import org.spongepowered.api.data.persistence.DataContainer;
 import org.spongepowered.api.entity.Entity;
 import org.spongepowered.api.entity.living.player.Player;
@@ -254,6 +256,15 @@ public final class ResourceKeyedValueParameters {
      */
     public static final DefaultedRegistryReference<ResourceKeyedValueParameter<Void>> NONE = ResourceKeyedValueParameters.key(ResourceKey.sponge("none"));
 
+    /**
+     * Expect an argument to represent an {@link Operator}
+     *
+     * <p>Valid operators are specified in {@link Operators}</p>
+     *
+     * <p>Returns an {@link Operator}</p>
+     */
+    public static final DefaultedRegistryReference<ResourceKeyedValueParameter<Operator>> OPERATOR = ResourceKeyedValueParameters.key(ResourceKey.sponge("operator"));
+
     /**
      * Expect an argument to represent an online player.
      *

src/main/java/org/spongepowered/api/registry/RegistryTypes.java

@@ -34,6 +34,7 @@ import org.spongepowered.api.block.entity.BlockEntityType;
 import org.spongepowered.api.block.transaction.Operation;
 import org.spongepowered.api.command.parameter.managed.ValueParameter;
 import org.spongepowered.api.command.parameter.managed.clientcompletion.ClientCompletionType;
+import org.spongepowered.api.command.parameter.managed.operator.Operator;
 import org.spongepowered.api.command.registrar.CommandRegistrarType;
 import org.spongepowered.api.command.registrar.tree.ClientCompletionKey;
 import org.spongepowered.api.command.selector.SelectorSortAlgorithm;
@@ -316,6 +317,8 @@ public final class RegistryTypes {
 
     public static final DefaultedRegistryType<ObjectiveDisplayMode> OBJECTIVE_DISPLAY_MODE = RegistryTypes.spongeKeyInGame("objective_display_mode");
 
+    public static final DefaultedRegistryType<Operator> OPERATOR = RegistryTypes.spongeKeyInGame("operator");
+
     public static final DefaultedRegistryType<Operation> OPERATION = RegistryTypes.spongeKeyInGame("operation");
 
     public static final DefaultedRegistryType<Orientation> ORIENTATION = RegistryTypes.spongeKeyInGame("orientation");