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author | Paul Phillips <paulp@improving.org> | 2011-09-08 18:37:18 +0000 |
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committer | Paul Phillips <paulp@improving.org> | 2011-09-08 18:37:18 +0000 |
commit | f32a32b1b33c9d7ccd62467e3e10cb69930023c8 (patch) | |
tree | 47ca34246fbdd255f2191ced68bd708e609d22d2 /test/files/neg/override-object-no.check | |
parent | 52c1d019d63d2fffadc8f3f159d654187ac61ece (diff) | |
download | scala-f32a32b1b33c9d7ccd62467e3e10cb69930023c8.tar.gz scala-f32a32b1b33c9d7ccd62467e3e10cb69930023c8.tar.bz2 scala-f32a32b1b33c9d7ccd62467e3e10cb69930023c8.zip |
Allow for the overriding of objects.
Various and sundry manipulations to allow for objects to be overridden
when the mood is right. It is not enabled by default.
The major contributor of change turned out to be the decoupling of
the FINAL flag (and the "isFinal" test which examines only that flag)
and the many semantics which were attributed to this interpretation
of finality in different circumstances. Since objects no longer have
the FINAL flag automatically applied (only top-level objects and those
marked final in source code do) we need apply a more nuanced test.
Fortunately there is such a nuanced test: isEffectivelyFinal,
which is always true if the FINAL flag is set but also in various
other circumstances. In almost every case, you should be testing
"isEffectivelyFinal", not "isFinal".
To enable overridable objects, use:
-Yoverride-objects
-Xexperimental // includes the above and others
Remain to be done: working out transition logistics. Most likely this
would involve bumping the scala signature version, and all objects in
versions before that would be assumed final.
Review by moors.
Diffstat (limited to 'test/files/neg/override-object-no.check')
-rw-r--r-- | test/files/neg/override-object-no.check | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/test/files/neg/override-object-no.check b/test/files/neg/override-object-no.check new file mode 100644 index 0000000000..c509634b3f --- /dev/null +++ b/test/files/neg/override-object-no.check @@ -0,0 +1,23 @@ +override-object-no.scala:14: error: overriding object Bar in trait Foo with object Bar in trait Foo2: +an overriding object must conform to the overridden object's class bound; + found : case1.Bippy with ScalaObject + required: case1.Bippy with case1.Bippo with ScalaObject + override object Bar extends Bippy { // err + ^ +override-object-no.scala:21: error: overriding object Bar in trait Quux1 with object Bar in trait Quux2: +an overriding object must conform to the overridden object's class bound; + found : java.lang.Object with ScalaObject{def g: java.lang.String} + required: java.lang.Object with ScalaObject{def g: Int} + trait Quux2 extends Quux1 { override object Bar { def g = "abc" } } // err + ^ +override-object-no.scala:25: error: overriding object Bar in trait Quux3 of type object Quux4.this.Bar; + object Bar cannot override final member + trait Quux4 extends Quux3 { override object Bar } // err + ^ +override-object-no.scala:43: error: overriding object A in class Foo with object A in class P2: +an overriding object must conform to the overridden object's class bound; + found : case2.Bar[List[String]] with ScalaObject + required: case2.Bar[Traversable[String]] with ScalaObject + override object A extends Bar[List[String]] // err + ^ +four errors found |