Parse array type in conditional operator #31050
Conversation
cston
changed the title
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@dotnet/roslyn-compiler, @gafter, please review. |
jcouv
added
Area-Compilers
Feature - Nullable Reference Types
| @@ -6262,7 +6245,7 @@ private enum ParseTypeMode | |||
| while (this.IsPossibleRankAndDimensionSpecifier()) | |||
| { | |||
| bool unused; | |||
| var rank = this.ParseArrayRankSpecifier(mode == ParseTypeMode.ArrayCreation, expectSizes, allowQuestionToken: true, out unused); | |||
| var rank = this.ParseArrayRankSpecifier(mode == ParseTypeMode.ArrayCreation, expectSizes, questionTokenModeOpt: mode, out unused); | |||
| ranks.Add(rank); | |||
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This appears to apply to all levels of a multidimensional array. Shouldn't it apply only to the last? That is, shouldn't we allow var z = e is int[]?[] ? x : y; (existing code)
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We allow e is int[]?[] ? x : y and e is int[]?[]? ? x : y. The issue was we were incorrectly parsing the first case by treating the ? from the conditional as a nullable qualifier on the array type.
I've added tests for arrays of arrays. Thanks.
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@dotnet/roslyn-compiler, please review. |
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@dotnet/roslyn-compiler please review. |
| } | ||
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| [Fact] | ||
| public void ConditionalOperator_NotNullableArray() |
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ConditionalOperator_NotNullableArray [](start = 20, length = 36)
Would it be useful to test x is T?[] y too? I'm afraid we disallow it, but I think we should allow it (seems useful).
Never mind, I think we allow it :-) Maybe still good to test
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@jaredpar What is the process for preview1 fixes? Thanks |
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Since there is a workaround (add parentheses), I'm pushing this back to preview2 (updated label and re-targeted PR). FYI @jaredpar |
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@jaredpar for approval for dev16.0-preview2. |
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approved |
Customer scenario
Parse error reported for array types used in conditional operator expression:
x is T[] ? y : zBugs this fixes
Internal issue
Workarounds, if any
Modify code. For instance, add parentheses:
(x is T[]) ? y : zRisk
Low.
Performance impact
None.
Is this a regression from a previous update?
Regression from C#7.3.
How was the bug found?
Customer report