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| Summary: | Lambda expression that returns the input param will hint it as an unused param | ||
|---|---|---|---|
| Product: | java | Reporter: | brettryan <brettryan> |
| Component: | Hints | Assignee: | Svata Dedic <sdedic> |
| Status: | RESOLVED WONTFIX | ||
| Severity: | normal | ||
| Priority: | P4 | ||
| Version: | 8.0 | ||
| Hardware: | PC | ||
| OS: | Mac OS X | ||
| Issue Type: | DEFECT | Exception Reporter: | |
This old bug may not be relevant anymore. If you can still reproduce it in 8.2 development builds please reopen this issue. Thanks for your cooperation, NetBeans IDE 8.2 Release Boss Thanks Martin, it appears the whole hint isn't even available anymore. I didn't even realise it was removed. I did often think to myself why the IDE wasn't hinting me about arguments I wasn't using in methods. What happened to this hint? It was actually useful, just not in the context of lambda methods. |
Given a lambda expression that simply returns its input, the editor hints that this parameter is unused. Given the following example the `collect` method returns a `Collectors.toMap` mapper who returns the input string for the key, the editor will warn that `str' is unused, which in fact it is. Map<String, Integer> stringLengths = Collections.<String>emptySet().stream() .collect(Collectors.toMap( str -> str, str -> str.length() )); Changing this to an explicit return within a lambda block will prevent the warning. Map<String, Integer> stringLengths = Collections.<String>emptySet().stream() .collect(Collectors.toMap( str -> { return str; }, str -> str.length() )); IMHO any input parameter to a lambda expression should be excluded from this rule as sometimes you may not use one of the input parameters. Product Version: NetBeans IDE Dev (Build 201401280001) Java: 1.7.0_51; Java HotSpot(TM) 64-Bit Server VM 24.51-b03 Runtime: Java(TM) SE Runtime Environment 1.7.0_51-b13 System: Mac OS X version 10.9.1 running on x86_64; UTF-8; en_AU (nb) User directory: /Users/bryan/Library/Application Support/NetBeans/dev Cache directory: /Users/bryan/Library/Caches/NetBeans/dev