Details
P3
Backports
| Issue | Fix Version | Assignee | Priority | Status | Resolution | Resolved In Build |
|---|---|---|---|---|---|---|
| JDK-8085288 | emb-9 | Jan Lahoda | P3 | Resolved | Fixed | team |
Description
Complete the removal, begun in Java SE 8, of underscore from the set of legal identifier names.
Issue Links
- relates to
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JDK-8065998
Avoid use of _ as a one-character identifier
-
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JDK-8042880
JEP 213: Milling Project Coin
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JDK-6415644
Make javax.lang.model.SourceVersion more informative
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1. |
3.9: Introduce underscore as a keyword | |
Resolved | Alex Buckley | ||
2. |
Avoid use of _ as a one-character identifier | |
Resolved | Jan Lahoda |
Activity
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Joe Darcy
added a comment -
Permalink
No known instances of using "_" as an identifier in the jdk or langtools repos, but the other repos would need to be tested.
Show
Joe Darcy
added a comment - No known instances of using "_" as an identifier in the jdk or langtools repos, but the other repos would need to be tested.
To demonstrate the output of the current proposed patch, consider this source code:
---
public interface Lambda {
public int a(int _);
public default void t(Lambda l) {
t(_ -> 0);
}
}
---
Compiling with JDK8, this leads to:
---
$ javac Lambda.java
Lambda.java:2: warning: '_' used as an identifier
public int a(int _);
^
(use of '_' as an identifier might not be supported in releases after Java SE 8)
Lambda.java:4: error: '_' used as an identifier
t(_ -> 0);
^
(use of '_' as an identifier is forbidden for lambda parameters)
1 error
1 warning
---
Compiling with the proposed patch and -source 9 leads to:
---
$ javac -source 9 Lambda.java
Lambda.java:2: error: as of release 9, '_' is a keyword, and may not be used as an identifier
public int a(int _);
^
Lambda.java:4: error: '_' used as an identifier
t(_ -> 0);
^
(use of '_' as an identifier is forbidden for lambda parameters)
2 errors
---
Compiling with the proposed patch and -source 8 leads to:
---
$ javac -source 8 Lambda.java
warning: [options] bootstrap class path not set in conjunction with -source 1.8
Lambda.java:2: warning: as of release 9, '_' is a keyword, and may not be used as an identifier
public int a(int _);
^
Lambda.java:4: error: '_' used as an identifier
t(_ -> 0);
^
(use of '_' as an identifier is forbidden for lambda parameters)
1 error
2 warnings
---
---
public interface Lambda {
public int a(int _);
public default void t(Lambda l) {
t(_ -> 0);
}
}
---
Compiling with JDK8, this leads to:
---
$ javac Lambda.java
Lambda.java:2: warning: '_' used as an identifier
public int a(int _);
^
(use of '_' as an identifier might not be supported in releases after Java SE 8)
Lambda.java:4: error: '_' used as an identifier
t(_ -> 0);
^
(use of '_' as an identifier is forbidden for lambda parameters)
1 error
1 warning
---
Compiling with the proposed patch and -source 9 leads to:
---
$ javac -source 9 Lambda.java
Lambda.java:2: error: as of release 9, '_' is a keyword, and may not be used as an identifier
public int a(int _);
^
Lambda.java:4: error: '_' used as an identifier
t(_ -> 0);
^
(use of '_' as an identifier is forbidden for lambda parameters)
2 errors
---
Compiling with the proposed patch and -source 8 leads to:
---
$ javac -source 8 Lambda.java
warning: [options] bootstrap class path not set in conjunction with -source 1.8
Lambda.java:2: warning: as of release 9, '_' is a keyword, and may not be used as an identifier
public int a(int _);
^
Lambda.java:4: error: '_' used as an identifier
t(_ -> 0);
^
(use of '_' as an identifier is forbidden for lambda parameters)
1 error
2 warnings
---
Attaching a simple finder for underscore as one-character identifiers. Needs tools.jar on classpath. Takes a single parameter, which is the directory that should be searched.
URL: http://hg.openjdk.java.net/jdk9/dev/langtools/rev/84a76798cff3
User: jlahoda
Date: 2014-12-08 17:16:47 +0000
User: jlahoda
Date: 2014-12-08 17:16:47 +0000
URL: http://hg.openjdk.java.net/jdk9/jdk9/langtools/rev/84a76798cff3
User: lana
Date: 2014-12-17 21:52:40 +0000
User: lana
Date: 2014-12-17 21:52:40 +0000