andreachild commented on code in PR #2919: URL: https://github.com/apache/tinkerpop/pull/2919#discussion_r1862775725
########## gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/GValue.java: ########## @@ -0,0 +1,451 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +package org.apache.tinkerpop.gremlin.process.traversal.step; + +import org.apache.tinkerpop.gremlin.process.traversal.Path; +import org.apache.tinkerpop.gremlin.process.traversal.Traversal; +import org.apache.tinkerpop.gremlin.structure.Edge; +import org.apache.tinkerpop.gremlin.structure.Element; +import org.apache.tinkerpop.gremlin.structure.Property; +import org.apache.tinkerpop.gremlin.structure.Vertex; + +import java.io.Serializable; +import java.math.BigDecimal; +import java.math.BigInteger; +import java.util.Collection; +import java.util.List; +import java.util.Map; +import java.util.Objects; +import java.util.Set; +import java.util.stream.Stream; + +/** + * A {@code GValue} is a variable or literal value that is used in a {@link Traversal}. It is composed of a key-value + * pair where the key is the name given to the variable and the value is the object that the variable resolved to. If + * the name is not given, the value was provided literally in the traversal. The value of the variable can be any + * object. The {@code GValue} also includes the {@link GType} that describes the type it contains. + */ +public class GValue<V> implements Cloneable, Serializable { + private final String name; + private final GType type; + + private final V value; + + private GValue(final GType type, final V value) { + this(null, type, value); + } + + private GValue(final String name, final GType type, final V value) { + if (name != null && name.startsWith("_")) { + throw new IllegalArgumentException(String.format("Invalid GValue name [%s]. Should not start with _.", name)); + } + this.name = name; + this.type = type; + this.value = value; + } + + /** + * Determines if the value held by this object was defined as a variable or a literal value. Literal values simply + * have no name. + */ + public boolean isVariable() { + return this.name != null; + } + + /** + * Gets the name of the variable if it was defined as such and returns empty if the value was a literal. + */ + public String getName() { + return this.name; + } + + /** + * Gets the type of the value. The explicit type could be determined with {@code instanceof} on the value, but this + * might be helpful for cases where the value was constructed with a {@code null} value which might just return as + * {@code Object}. + */ + public GType getType() { + return this.type; + } + + /** + * Determines if the value held is of a {@code null} value. + */ + public boolean isNull() { + return this.value == null; + } + + /** + * Gets the value. + */ + public V get() { + return this.value; + } + + @Override + public String toString() { + return isVariable() ? + String.format("%s&%s", name, value) : Objects.toString(value); + } + + @Override + public boolean equals(final Object o) { + if (this == o) return true; + if (o == null || getClass() != o.getClass()) return false; + final GValue<?> gValue = (GValue<?>) o; + return Objects.equals(name, gValue.name) && type == gValue.type && Objects.equals(value, gValue.value); + } + + @Override + public int hashCode() { + return Objects.hash(name, type, value); + } + + @Override + public GValue<V> clone() { + return new GValue<>(this.name, this.type, this.value); + } + + /** + * Create a new {@code Var} from a particular value but without the specified name. If the argument provide is + * already a {@code GValue} then it is returned as-is. + * + * @param value the value of the variable + */ + static <V> GValue<V> of(final V value) { + if (value instanceof GValue) return (GValue) value; + return new GValue<>(GType.getType(value), value); + } + + /** + * Create a new {@code Var} with the specified name and value.. If the argument provide is already a + * {@code GValue} then it is returned as-is. + * + * @param name the name of the variable + * @param value the value of the variable + */ + public static <V> GValue<V> of(final String name, final V value) { + if (value instanceof GValue) throw new IllegalArgumentException("value cannot be a GValue"); + return new GValue<>(name, GType.getType(value), value); + } + + /** + * Create a new {@code GValue} for a string value. + */ + static GValue<String> ofString(final String value) { + return new GValue<>(GType.STRING, value); + } + + /** + * Create a new {@code GValue} for a string value with a specified name. + */ + public static GValue<String> ofString(final String name, final String value) { + return new GValue<>(name, GType.STRING, value); + } + + /** + * Create a new {@code GValue} for an integer value. + */ + static GValue<Integer> ofInteger(final Integer value) { + return new GValue<>(GType.INTEGER, value); + } + + /** + * Create a new {@code GValue} for an integer value with a specified name. + */ + public static GValue<Integer> ofInteger(final String name, final Integer value) { + return new GValue<>(name, GType.INTEGER, value); + } + + /** + * Create a new {@code GValue} for a boolean value. + */ + static GValue<Boolean> ofBoolean(final Boolean value) { + return new GValue<>(GType.BOOLEAN, value); + } + + /** + * Create a new {@code GValue} for a boolean value with a specified name. + */ + public static GValue<Boolean> ofBoolean(final String name, final Boolean value) { + return new GValue<>(name, GType.BOOLEAN, value); + } + + /** + * Create a new {@code GValue} for a double value. + */ + static GValue<Double> ofDouble(final Double value) { + return new GValue<>(GType.DOUBLE, value); + } + + /** + * Create a new {@code GValue} for a double value with a specified name. + */ + public static GValue<Double> ofDouble(final String name, final Double value) { + return new GValue<>(name, GType.DOUBLE, value); + } + + /** + * Create a new {@code GValue} for a BigInteger value. + */ + static GValue<BigInteger> ofBigInteger(final BigInteger value) { + return new GValue<>(GType.BIG_INTEGER, value); + } + + /** + * Create a new {@code GValue} for a BigInteger value with a specified name. + */ + public static GValue<BigInteger> ofBigInteger(final String name, final BigInteger value) { + return new GValue<>(name, GType.BIG_INTEGER, value); + } + + /** + * Create a new {@code GValue} for a BigDecimal value. + */ + static GValue<BigDecimal> ofBigDecimal(final BigDecimal value) { + return new GValue<>(GType.BIG_DECIMAL, value); + } + + /** + * Create a new {@code GValue} for a BigDecimal value with a specified name. + */ + public static GValue<BigDecimal> ofBigDecimal(final String name, final BigDecimal value) { + return new GValue<>(name, GType.BIG_DECIMAL, value); + } + + /** + * Create a new {@code GValue} for a long value. + */ + static GValue<Long> ofLong(final Long value) { + return new GValue<>(GType.LONG, value); + } + + /** + * Create a new {@code GValue} for a long value with a specified name. + */ + public static GValue<Long> ofLong(final String name, final Long value) { + return new GValue<>(name, GType.LONG, value); + } + + /** + * Create a new {@code GValue} for a map value. + */ + static GValue<Map> ofMap(final Map value) { + return new GValue<>(GType.MAP, value); + } + + /** + * Create a new {@code GValue} for a map value with a specified name. + */ + public static GValue<Map> ofMap(final String name, final Map value) { + return new GValue<>(name, GType.MAP, value); + } + + /** + * Create a new {@code GValue} for a list value. + */ + static <T> GValue<List<T>> ofList(final List<T> value) { + return new GValue<>(GType.LIST, value); + } + + /** + * Create a new {@code GValue} for a list value with a specified name. + */ + public static <T> GValue<List<T>> ofList(final String name, final List<T> value) { + return new GValue<>(name, GType.LIST, value); + } + + /** + * Create a new {@code GValue} for a set value. + */ + static GValue<Set> ofSet(final Set value) { + return new GValue<>(GType.SET, value); + } + + /** + * Create a new {@code GValue} for a set value with a specified name. + */ + public static GValue<Set> ofSet(final String name, final Set value) { + return new GValue<>(name, GType.SET, value); + } + + /** + * Create a new {@code GValue} for a vertex value. + */ + static GValue<Vertex> ofVertex(final Vertex value) { + return new GValue<>(GType.VERTEX, value); + } + + /** + * Create a new {@code GValue} for a vertex value with a specified name. + */ + public static GValue<Vertex> ofVertex(final String name, final Vertex value) { + return new GValue<>(name, GType.VERTEX, value); + } + + /** + * Create a new {@code GValue} for an edge value. + */ + static GValue<Edge> ofEdge(final Edge value) { + return new GValue<>(GType.EDGE, value); + } + + /** + * Create a new {@code GValue} for an edge value with a specified name. + */ + public static GValue<Edge> ofEdge(final String name, final Edge value) { + return new GValue<>(name, GType.EDGE, value); + } + + /** + * Create a new {@code GValue} for a path value. + */ + static GValue<Path> ofPath(final Path value) { + return new GValue<>(GType.PATH, value); + } + + /** + * Create a new {@code GValue} for a path value with a specified name. + */ + public static GValue<Path> ofPath(final String name, final Path value) { + return new GValue<>(name, GType.PATH, value); + } + + /** + * Create a new {@code GValue} for a property value. + */ + static GValue<Property> ofProperty(final Property value) { + return new GValue<>(GType.PROPERTY, value); + } + + /** + * Create a new {@code GValue} for a property value with a specified name. + */ + public static GValue<Property> ofProperty(final String name, final Property value) { + return new GValue<>(name, GType.PROPERTY, value); + } + + /** + * If the object is a {@code GValue} then get its value, otherwise return the object as-is. + */ + public static <T> T getFrom(final Object o) { + return o instanceof GValue ? ((GValue<T>) o).get() : (T) o; + } + + /** + * Tests if the object is a {@link GValue} and if so, checks the type of the value against the provided + * {@link GType}. + */ + public static boolean valueInstanceOf(final Object o, final GType type) { + return o instanceof GValue && ((GValue) o).getType() == type; + } + + /** + * Tests if the object is a {@link GValue} and if so, checks if the type of the value is a collection. + */ + public static boolean valueInstanceOfCollection(final Object o) { + return o instanceof GValue && ((GValue) o).getType().isCollection(); + } + + /** + * Tests if the object is a {@link GValue} and if so, checks if the type of the value is a numeric. + */ + public static boolean valueInstanceOfNumeric(final Object o) { + return o instanceof GValue && ((GValue) o).getType().isNumeric(); + } + + /** + * Checks the type of the object against the provided {@link GType}. If the object is a {@link GValue} then it + * can directly check the type, otherwise it will test the given object's class itself using the mapping on the + * {@link GType}. + */ + public static boolean instanceOf(final Object o, final GType type) { + if (null == o) + return false; + else if (o instanceof GValue) + return ((GValue) o).getType() == type; + else + return type.getJavaType().isAssignableFrom(o.getClass()); + } + + /** + * Returns {@code true} if the object is a collection or a {@link GValue} that contains a {@link Collection}. + */ + public static boolean instanceOfCollection(final Object o) { + return o instanceof Collection || (o instanceof GValue && ((GValue) o).getType().isCollection()); + } + + /** + * Returns {@code true} if the object is an element or a {@link GValue} that contains an {@link Element}. + */ + public static boolean instanceOfElement(final Object o) { + return o instanceof Element || (o instanceof GValue && ((GValue) o).getType().isElement()); + } + + /** + * Returns {@code true} if the object is a number or a {@link GValue} that contains a number. + */ + public static boolean instanceOfNumber(final Object o) { + return o instanceof Number || (o instanceof GValue && ((GValue) o).getType().isNumeric()); Review Comment: Nit: can reuse logic of `valueInstanceOfNumeric`: ``` return o instanceof Number || valueInstanceOfNumeric(o); ``` -- This is an automated message from the Apache Git Service. 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