Use more effective evaluation order in LanguagePrimitives.IsNullLike() #10781
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Collaborator
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It was in #9794 (milestone 7.0-Preview2) as a breaking change without PowerShell Committee approve. So add the labels. |
iSazonov
approved these changes
Oct 12, 2019
Collaborator
Author
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@iSazonov the committee approved the change in the original issue (see #9561 (comment)) 🙂 |
Collaborator
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My concern about order. |
Member
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Why is changing the order a breaking change? It doesn't change the behavior of this method, does it? |
Collaborator
Author
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Nope, it still checks the same things, just in a different order. 🙂 |
Collaborator
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I see the logic is more simple than I thought. |
adityapatwardhan
approved these changes
Oct 15, 2019
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🎉 Handy links: |
daxian-dbw
added a commit
to daxian-dbw/PowerShell
that referenced
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Jan 14, 2020
…ullLike() (PowerShell#10781)" This reverts commit 25286eb.
This was referenced Jan 14, 2020
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PR Summary
Refactor
IsNullLike()to evaluate the most commonly-expectednull-like values first.New order of evaluation:
IsNull(value):value == nullvalue == AutomationNull.Valuevalue == DBNull.Valuevalue == AutomationNull.ValuePR Context
IsNullLike()is used in binders like-eq(e.g.,$null -eq $value)and it makes the most sense to evaluate in order of the most common null/null-like values first so that the code path short-circuits in the most common situations.PR Checklist
.h,.cpp,.cs,.ps1and.psm1files have the correct copyright headerWIP:or[ WIP ]to the beginning of the title (theWIPbot will keep its status check atPendingwhile the prefix is present) and remove the prefix when the PR is ready.