feat: Allow type parameters on newtypes #5495
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The generated SMT is different than before, because of the soundness fix that removes the `where` clause of the well-formedness check of subset/new-types.
# Conflicts: # Source/DafnyCore/Resolver/PreType/PreTypeResolve.Expressions.cs
# Conflicts: # Source/DafnyCore/AST/Grammar/Printer/Printer.cs # Source/IntegrationTests/TestFiles/LitTests/LitTest/dafny0/PrettyPrinting.dfy # Source/IntegrationTests/TestFiles/LitTests/LitTest/dafny0/PrettyPrinting.dfy.expect
# Conflicts: # Source/DafnyCore/Verifier/BoogieGenerator.Types.cs
ssomayyajula
previously approved these changes
Aug 26, 2024
Variance does not need to be considered here, because type parameters with non-co variance that should be excluded from these type-refinement flows have already been marked as such (by omitting the bottom wrapper in `PreType2RefinableType`).
ssomayyajula
approved these changes
Aug 26, 2024
dnezam
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to dnezam/dafny
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Aug 29, 2024
This PR adds the following language features: * type parameters of `newtype` declarations * optional `witness` clause of constraint-less `newtype` declarations * tool tips show auto-completed type parameters * tool tips show inferred `(==)` characteristics Along the way, the PR also fixes two previous soundness issues: * fix: Check the emptiness status of constraint-less `newtype` declarations (dafny-lang#5520) * fix: Don't let `newtype` well-formedness checking affect witness checking (dafny-lang#5521) Fixes dafny-lang#5520 Fixes dafny-lang#5521 <small>By submitting this pull request, I confirm that my contribution is made under the terms of the [MIT license](https://github.com/dafny-lang/dafny/blob/master/LICENSE.txt).</small>
dnezam
pushed a commit
to dnezam/dafny
that referenced
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Sep 21, 2024
This PR adds the following language features: * type parameters of `newtype` declarations * optional `witness` clause of constraint-less `newtype` declarations * tool tips show auto-completed type parameters * tool tips show inferred `(==)` characteristics Along the way, the PR also fixes two previous soundness issues: * fix: Check the emptiness status of constraint-less `newtype` declarations (dafny-lang#5520) * fix: Don't let `newtype` well-formedness checking affect witness checking (dafny-lang#5521) Fixes dafny-lang#5520 Fixes dafny-lang#5521 <small>By submitting this pull request, I confirm that my contribution is made under the terms of the [MIT license](https://github.com/dafny-lang/dafny/blob/master/LICENSE.txt).</small>
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This PR adds the following language features:
newtypedeclarationswitnessclause of constraint-lessnewtypedeclarations(==)characteristicsIt also makes a breaking change in what's allowed in refinement modules, namely that a refinement module is no longer allowed to rename type parameters. Since comparisons during these refinement checks are done syntactically, it gets difficult to make sure the types in the refinement module really mean the same thing as in the original module. Having the ability to rename type parameters here does not seem like an important feature, so it was easier to just be more strict about it. (Note, there are some cases where type parameters can be renamed when going from a trait to a type that implements the trait. Those comparisons are done with semantic information, so they can be done reliably.)
Along the way, the PR also fixes two previous soundness issues:
newtypedeclarations (Base type throws off witness checking #5520)newtypewell-formedness checking affect witness checking (Constraint-less newtypes assumed to be nonempty #5521)Fixes #5520
Fixes #5521
By submitting this pull request, I confirm that my contribution is made under the terms of the MIT license.