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https://issues.apache.org/jira/browse/TINKERPOP-3166?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18004317#comment-18004317
]
ASF GitHub Bot commented on TINKERPOP-3166:
-------------------------------------------
Cole-Greer commented on code in PR #3153:
URL: https://github.com/apache/tinkerpop/pull/3153#discussion_r2196348405
##########
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/AsNumberStep.java:
##########
@@ -0,0 +1,192 @@
+/*
+ * 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.map;
+
+import org.apache.commons.lang3.math.NumberUtils;
+import org.apache.tinkerpop.gremlin.process.traversal.N;
+import org.apache.tinkerpop.gremlin.process.traversal.Traversal;
+import org.apache.tinkerpop.gremlin.process.traversal.Traverser;
+import
org.apache.tinkerpop.gremlin.process.traversal.traverser.TraverserRequirement;
+import org.apache.tinkerpop.gremlin.structure.util.StringFactory;
+import org.apache.tinkerpop.gremlin.util.NumberHelper;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.util.Calendar;
+import java.util.Collections;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Reference implementation for number parsing step.
+ */
+public final class AsNumberStep<S> extends ScalarMapStep<S, Number> {
+
+ private N numberToken;
+
+ public AsNumberStep(final Traversal.Admin traversal) {
+ super(traversal);
+ this.numberToken = null;
+ }
+
+ public AsNumberStep(final Traversal.Admin traversal, final N numberToken) {
+ super(traversal);
+ this.numberToken = numberToken;
+ }
+
+ @Override
+ protected Number map(Traverser.Admin<S> traverser) {
+ final Object object = traverser.get();
+ if (object instanceof String) {
+ String numberText = (String) object;
+ Number number = parseNumber(numberText);
+ return numberToken == null ? autoNumber(number) :
castNumber(number, numberToken);
+ } else if (object instanceof Number) {
+ Number number = (Number) object;
+ return numberToken == null ? autoNumber(number) :
castNumber(number, numberToken);
+ }
+ throw new IllegalArgumentException(String.format("Can't parse type %s
as number.", object == null ? "null" : object.getClass().getSimpleName()));
+ }
+
+ @Override
+ public Set<TraverserRequirement> getRequirements() {
+ return Collections.singleton(TraverserRequirement.OBJECT);
+ }
+
+ @Override
+ public void setTraversal(final Traversal.Admin<?, ?> parentTraversal) {
+ super.setTraversal(parentTraversal);
+ }
+
+ @Override
+ public int hashCode() {
+ int result = super.hashCode();
+ result = 31 * result + (numberToken != null ? numberToken.hashCode() :
0);
+ return result;
+ }
+
+ @Override
+ public AsNumberStep<S> clone() {
+ final AsNumberStep<S> clone = (AsNumberStep<S>) super.clone();
+ clone.numberToken = this.numberToken;
+ return clone;
+ }
+
+ @Override
+ public String toString() {
+ return StringFactory.stepString(this);
+ }
+
+ public static Number parseNumber(final String value) {
+ try {
+ boolean isFloatingPoint = value.contains(".") ||
value.contains("e") || value.contains("E");
+ if (isFloatingPoint) {
+ BigDecimal result = new BigDecimal(value.trim());
+ if (BigDecimal.valueOf(result.doubleValue()).compareTo(result)
== 0) {
+ return result.doubleValue();
+ }
+ return result;
+ }
+ BigInteger result = new BigInteger(value.trim());
+ if (result.bitLength() <= 31) { // default to int if not
specified, smaller sizes need to be intentionally set
+ return result.intValue();
+ } else if (result.bitLength() <= 63) {
+ return result.longValue();
+ }
+ return result;
+ } catch (NumberFormatException nfe) {
+ throw new NumberFormatException(String.format("Can't parse string
'%s' as number.", value));
+ }
+ }
+
+ private static Number autoNumber(Number number) {
+ final Class<? extends Number> clazz = number.getClass();
+ if (clazz.equals(Float.class)) {
+ return castNumber(number, N.ndouble);
+ }
+ return number;
+ }
+
+ private static Number castNumber(Number number, N numberToken) {
+ int sourceBits = getNumberBitsBasedOnValue(number);
+ int targetBits = getNumberTokenBits(numberToken);
+ if (sourceBits > targetBits) {
+ throw new ArithmeticException(String.format("Can't convert number
of type %s to %s due to overflow.",
+ number.getClass().getSimpleName(),
numberToken.toString()));
+ }
+ if (numberToken == N.nbyte) {
+ return number.byteValue();
+ } else if (numberToken == N.nshort) {
+ return number.shortValue();
+ } else if (numberToken == N.nint) {
+ return number.intValue();
+ } else if (numberToken == N.nlong) {
+ return number.longValue();
+ } else if (numberToken == N.nfloat) {
+ return number.floatValue();
+ } else if (numberToken == N.ndouble) {
+ return number.doubleValue();
+ } else if (numberToken == N.nbigInt) {
+ return BigInteger.valueOf(number.longValue());
Review Comment:
This could result in precision loss if `number` is a `float`, `double`,
`BigDecimal`, or `BigInteger` which stores a value outside of the range of
`long`
```
BigInteger.valueOf(92233720368547758070.0.longValue()) //Long.MAX_VALUE * 10
==>-10
```
> Add number conversion step asNumber()
> -------------------------------------
>
> Key: TINKERPOP-3166
> URL: https://issues.apache.org/jira/browse/TINKERPOP-3166
> Project: TinkerPop
> Issue Type: Improvement
> Components: language
> Affects Versions: 3.8.0
> Reporter: Yang Xia
> Priority: Major
>
> Given the addition of the {{asString()}} and {{asDate()}} steps in the 3.7
> line, it should also be helpful to add an {{asNumber()}} step that does
> numerical casting/conversions.
> The current idea is for the {{asNumber()}} step to convert the incoming
> traverser to the nearest parsable type (e.g. int or double) if no argument is
> provided, or to the desired numerical type, based on a number token
> ({{{}N{}}}) provided. Like the {{asDate()}} step, it will not be scoped (for
> now, scopes can be added in the future).
> Some conjured examples:
> {code:java}
> gremlin> g.inject(5).asNumber()
> ==> 5 // parses to int
> gremlin> g.inject(5.123f).asNumber()
> ==> 5.123
> gremlin> g.inject(5.43).asNumber(N.int)
> ==> 5 {code}
> More details can be found in the [proposal
> doc|https://github.com/apache/tinkerpop/blob/master/docs/src/dev/future/proposal-asnumber-step-6.asciidoc].
>
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