X10

Type bounds do not play nice with coercions

Details

  • Testcase included:
    yes
  • Number of attachments :
    0

Description

The following code:

public class XTENLANG_2480 {
    public static def main(Array[String]) {
        val v <: Double = 3;
    }
}

fails to compile with this error:

./XTENLANG_2480.x10:3: Computed type is not a subtype of type bound.    
         Computed Type: x10.lang.Int{self==3}    
         Type Bound: x10.lang.Double
1 error.

while changing <: to : makes compilation succeed.
Typechecking partial types should attempt coercing the initializer to the type bound before reporting an error.

Issue Links

is depended upon by

Bug - A problem which impairs or prevents the functions of the product. XTENLANG-2484 clarification needed for accessing static fields in a class via native code

  • 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.

Task - A task that needs to be done. XTENLANG-2971 Umbrella language/front-end JIRA for X10 2.4

  • Critical - Crashes, loss of data, severe memory leak.
  • Open - The issue is open and ready for the assignee to start work on it.
relates to

Bug - A problem which impairs or prevents the functions of the product. XTENLANG-2487 Method Resolution doesn't handle user-defined implicit coercions correctly.

  • Critical - Crashes, loss of data, severe memory leak.
  • Open - The issue is open and ready for the assignee to start work on it.

Bug - A problem which impairs or prevents the functions of the product. XTENLANG-2435 When inferring the return type, we should consider overriding methods and HasType.

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

Bug - A problem which impairs or prevents the functions of the product. XTENLANG-2526 Specify "operator (x:T) as ? <: U "

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

Improvement - An improvement or enhancement to an existing feature or task. XTENLANG-1151 <:-declarations should try type conversions, too.

  • 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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Igor Peshansky added a comment -

Fixed for fields and locals in r20384.
Fixing this for method/closure return types requires inserting coercions at return points. This means that the partial type bound needs to be in context as we're typechecking the method body, so that we can generate the appropriate coercions in one pass.

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Igor Peshansky added a comment - Fixed for fields and locals in r20384. Fixing this for method/closure return types requires inserting coercions at return points. This means that the partial type bound needs to be in context as we're typechecking the method body, so that we can generate the appropriate coercions in one pass.
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Igor Peshansky added a comment -

This can be done in a backward-compatible fashion. Deferring to 2.2.1.

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Igor Peshansky added a comment - This can be done in a backward-compatible fashion. Deferring to 2.2.1.
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Yoav Zibin added a comment -

This is the problem:

class XTENLANG_2480 {
	val f <: Double = 3;	
    def m() {
        val local <: Double = 3;
    }
	def v() <: Double { return 3; } // ShouldNotBeERR
}
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Yoav Zibin added a comment - This is the problem: class XTENLANG_2480 { val f <: Double = 3; def m() { val local <: Double = 3; } def v() <: Double { return 3; } // ShouldNotBeERR }
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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:
    Igor Peshansky
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Dates

  • Created:
    Updated: