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https://issues.apache.org/jira/browse/TINKERPOP-3166?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18009354#comment-18009354
]
ASF GitHub Bot commented on TINKERPOP-3166:
-------------------------------------------
Cole-Greer commented on code in PR #3153:
URL: https://github.com/apache/tinkerpop/pull/3153#discussion_r2226368605
##########
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/util/NumberHelper.java:
##########
@@ -721,6 +723,86 @@ public static Number coerceTo(final Number a, final
Class<? extends Number> claz
return a;
}
+ /**
+ * Casts the given number to the specified numeric type if it can fit into
it.
+ * Otherwise, throw.
+ *
+ * @param a the number to be cast
+ * @param numberToken the number token denoting the desired type to cast
+ * @return the number cast to the specified type
+ * @throws IllegalArgumentException if the specified numeric type is
unsupported
+ * @throws ArithmeticException if the number overflows
+ */
+ public static Number castTo(final Number a, final N numberToken) {
+ Class<?> clazz = numberToken.getType();
+ if (a.getClass().equals(clazz)) {
+ return a;
+ } else if (clazz.equals(Integer.class)) {
+ Long val = getLong(a, numberToken);
+ if (val >= Integer.MIN_VALUE && val <= Integer.MAX_VALUE) {
+ return a.intValue();
+ }
+ } else if (clazz.equals(Long.class)) {
+ return getLong(a, numberToken);
Review Comment:
There's a strange inconsistency that arises by using long as the
intermediate form for all of these integer types.
```
gremlin> g.inject(new Double(Integer.MAX_VALUE+"1")).asNumber(N.nint)
Can't convert number of type Double to Integer due to overflow.
Type ':help' or ':h' for help.
gremlin> g.inject(new Double(Long.MAX_VALUE+"1")).asNumber(N.nlong)
==>9223372036854775807
```
Double.longValue() does a primitive cast from `double` to `long`, which
implicitly binds out-of-range values to Long.MAX_VALUE or Long.MIN_VALUE.
Perhaps an extra check is needed in getLong() to throw an exception if the
value exceeds the range of a long. The same concern would apply to
float-to-long conversions.
> 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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