X10

if Foo is coercible to Baz, "for (b:Baz in (x as Iterable[Foo])" should be legal

Details

  • Testcase included:
    yes
  • Number of attachments :
    2

Description

Given a class Foo with operator this: Baz, the following code does not compile:

val lf: List[Foo] = new ArrayList[Foo]();
for (i: Baz in lf) {
    Console.OUT.println(i);
}

./IterableTest.x10:24-26: ERROR: Loop domain x10.util.List[IterableTest.Foo]

{self==lf}

is not a subtype of Iterable[IterableTest.Baz].
1 error.

  1. File
    IterableTest.x10
    03/May/10 2:16 PM
    0.8 kB
    Bowen Alpern
  2. File
    TestIterableSubclass.x10
    23/May/10 4:12 AM
    0.8 kB
    Josh Milthorpe

Issue Links

is depended upon by

New Feature - A new feature of the product, which has yet to be developed. XTENLANG-1365 Support for periodic array access

  • Major - Major loss of function.
  • Closed - The issue is considered finished, the resolution is correct. Issues which are not closed can be reopened.

Improvement - An improvement or enhancement to an existing feature or task. XTENLANG-2439 X10 2.2 language design decisions (umbrella)

  • Blocker - Blocks development and/or testing work, production could not run
  • Closed - The issue is considered finished, the resolution is correct. Issues which are not closed can be reopened.
relates to

Bug - A problem which impairs or prevents the functions of the product. XTENLANG-1415 "for loops" are rejected if the constraint is wrong even for DYNAMIC_CALLS

  • Major - Major loss of function.
  • Closed - The issue is considered finished, the resolution is correct. Issues which are not closed can be reopened.

Activity

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Josh Milthorpe added a comment -

A related problem is that a subclass of any Iterable class is not itself Iterable if the interface implementation refers to a field of the supertype.
Concretely, this means that a subclass of DistArray cannot be iterated, because DistArray implements Iterable[Point(dist.region.rank)]. A simplified example is attached in TestIterableSubclass.x10

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Josh Milthorpe added a comment - A related problem is that a subclass of any Iterable class is not itself Iterable if the interface implementation refers to a field of the supertype. Concretely, this means that a subclass of DistArray cannot be iterated, because DistArray implements Iterable [Point(dist.region.rank)] . A simplified example is attached in TestIterableSubclass.x10
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Josh Milthorpe added a comment -

The compile error for TestIterableSubclass.x10 is:

ERROR: Loop domain TestIterableSubclass.B{self==b, b.home==TestIterableSubclass#this.home, b!=null} 
is not a subtype of Iterable[x10.array.Point{self.rank==TestIterableSubclass.A#this.region.rank}].

This appears to be because the check for subtype in X10ForLoop_c.java (line 169) is comparing
{{val Iterable : x10.lang.Iterable[x10.array.Point

{self.rank==TestIterableSubclass.A#this.region.rank}

]}}
against domainType, which implements non-matching constraints e.g.
{{x10.lang.Iterable[x10.array.Point

{self.rank==_8750.region.rank}

]}}.

Show
Josh Milthorpe added a comment - The compile error for TestIterableSubclass.x10 is: ERROR: Loop domain TestIterableSubclass.B{self==b, b.home==TestIterableSubclass#this.home, b!=null} is not a subtype of Iterable[x10.array.Point{self.rank==TestIterableSubclass.A#this.region.rank}]. This appears to be because the check for subtype in X10ForLoop_c.java (line 169) is comparing {{val Iterable : x10.lang.Iterable[x10.array.Point {self.rank==TestIterableSubclass.A#this.region.rank} ]}} against domainType , which implements non-matching constraints e.g. {{x10.lang.Iterable[x10.array.Point {self.rank==_8750.region.rank} ]}}.
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David Grove added a comment -

defer all non-critical X10 issues to 2.1.0.

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David Grove added a comment - defer all non-critical X10 issues to 2.1.0.
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Yoav Zibin added a comment -

1) Regarding Bowen's "bug" - it is a feature request. The spec doesn't say anything about "for" loops and coercions.
2) Regarding Josh's bug - it is a bug in inferring the type of the index.
Both bugs have simple work-arounds:
Bowen - iterate with an index:Foo, and then assign to Baz.
Josh - specify the type of the index explicitly.
I'm leaving this bug open and continue to work on it, but there is a simple work-around.

Show
Yoav Zibin added a comment - 1) Regarding Bowen's "bug" - it is a feature request. The spec doesn't say anything about "for" loops and coercions. 2) Regarding Josh's bug - it is a bug in inferring the type of the index. Both bugs have simple work-arounds: Bowen - iterate with an index:Foo, and then assign to Baz. Josh - specify the type of the index explicitly. I'm leaving this bug open and continue to work on it, but there is a simple work-around.
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Bard Bloom added a comment -

Deferred to 2.1.0

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Bard Bloom added a comment - Deferred to 2.1.0
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David Grove added a comment -

bulk defer of unresolved 2.1.0 bugs to 2.1.1.

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David Grove added a comment - bulk defer of unresolved 2.1.0 bugs to 2.1.1.
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David Grove added a comment -

bulk move of all unresolved issues from 2.1.1 to 2.1.2

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David Grove added a comment - bulk move of all unresolved issues from 2.1.1 to 2.1.2
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David Grove added a comment -

defer all non-critical 2.1.2 issues to 2.2.

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David Grove added a comment - defer all non-critical 2.1.2 issues to 2.2.
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Vijay Saraswat added a comment -

As far as language design issues are concerned, I do agree with Bowen that IterableTest.x10 should work.

Also with Josh – there is a bug in the type inferencer.

Both of these problems do not cause backward compatibility problems, and there are easy workarounds, hence deferred to 2.2.1.

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Vijay Saraswat added a comment - As far as language design issues are concerned, I do agree with Bowen that IterableTest.x10 should work. Also with Josh – there is a bug in the type inferencer. Both of these problems do not cause backward compatibility problems, and there are easy workarounds, hence deferred to 2.2.1.
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David Grove added a comment -

bulk defer of open issues to 2.2.2.

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David Grove added a comment - bulk defer of open issues to 2.2.2.
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David Grove added a comment -

bulk defer of issues to 2.2.3.

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David Grove added a comment - bulk defer of issues to 2.2.3.
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David Grove added a comment -

bulk defer of 2.3.0 open issues to 2.3.1.

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David Grove added a comment - bulk defer of 2.3.0 open issues to 2.3.1.
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David Grove added a comment -

bulk defer to 2.3.2

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David Grove added a comment - bulk defer to 2.3.2

People

  • Assignee:
    Unassigned
    Reporter:
    Bowen Alpern
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Dates

  • Created:
    Updated: