Relates to #1881
Features:
* Add basic support for `abstract` class
* Allow extending an abstract class
* Prevent direct instantiation of an abstract class
Changes:
* Check that class extensibility for `VariableDefinition` is not `Abstract`
* Add corresponding set of lit tests
Relates to https://github.com/carbon-language/carbon-lang/issues/1881
- Add support for `.base` field in structs for [parent class initialization](https://github.com/carbon-language/carbon-lang/blob/trunk/docs/design/classes.md#constructors)
- Disabling base class initialization without `.base`
- Support class constructors (`Create() -> Self`) for base classes
- Direct access to base class(es) attributes with `object.var` remains unaffected
Changes:
- Add `TypeChecker::FieldTypesWithBase` to help assessing if a struct with `base` fields can be converted to a class
- Add a new `base_type()` attribute+getter to `NominalClassDeclaration` to as a first step to allow resolving parametrized classes
- Add a new `base` attribute+getter to `NominalClassValue` that contains the base class `NominalClassValue`. It is currently used mainly to get and set members of a class object.
- Add `Interpreter::ConvertClassWithBase` to build `NominalClassValue` from a init struct, that contains `.base` fields with either `NominalClassValue` or `StructValue`
- Add `FindClassField` to find a field in a class or its base classes
- Remove superfluous `ClassDeclaration::base()` in favor of `ClassDeclaration::base_type()`
Limitations;
- Though some work is done in that direction, parametrized base class where time is not know at the declaration site are not supported. Namely the example below does not compile
```
base class A(T:! Type) {}
class B(T:! Type) extends A(T) {}
```
But this one is functional already
```
base class A(T:! Type) {}
class B extends A(i32) {}
```
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Patterns all compute their values when type-checked, so we never
actually need to do any multi-step evaluation to compute the value of a
pattern. Doing so was leading to quadratic runtime and excess noise in
the trace file.
This PR includes the following changes:
* Added destruction process for tuples
* Fix: In the current version only the last member of a object can be destroyed
* Fix: In the current version, the destructor of the object is called after each method call
I hope it is useful
Co-authored-by: m new <michael.burzan@outlook.de>
Co-authored-by: Geoff Romer <gromer@google.com>
In particular, this means that a type can implement `ImplicitAs(Type)` and have values of that type behave like types.
This implies that `()` and `{}` are no longer types. They are now values whose type is the result of converting `()` or `{}` to type `Type`, as has been discussed recently and seems to be the supported direction. This fixes various cases where these types were previously mishandled.
When resolving a constraint type, compute the fixed point of the specified rewrite constraints, as requested by @josh11b in review of #2173 and tentatively agreed as our direction. If no such fixed point exists, detect that situation and diagnose the problem.
The algorithm used here is to iteratively apply all rewrites to each rewrite constraint until either one of them refers to itself, which indicates there's a cycle in the rewrite graph, or the set of rewrites converges.
This algorithm has some pathological inputs in which the runtime can grow exponentially in the size of the input (indeed, the fully-rewritten set of rewrites can grow exponentially in the size of the input, so this is unavoidable), so an iteration limit is also provided.
Prior to this change, declarations like `let N:! X(.Self) where .(X(.Self).Y) == 5;` have the surprising behavior of the two `.Self` expressions resolving to two different symbolic values. Fix this by forcing the inner one to have the same symbolic value as the outer one, albeit with a different type.
Per recent discussion, in `... where .A = B`, require that `B` is implicitly convertible to the type of `A` immediately, rather than treating that as part of the criteria that a type must satisfy to satisfy the resulting constraint. Extend the implementation of implicit conversion so that conversion of a type to a constraint checks that the type satisfies the constraint.
As part of implementing this, stop duplicating rewrite constraints as equality constraints. Instead, when checking that a constraint is satisfied, check both its equality constraints and its rewrite constraints. This fixes an infinite recursion that would otherwise be caused by this change, and is also a necessary prerequisite for applying rewrite constraints to equality constraints, where we would otherwise collapse the implied equality constraints to a tautological `V == V` constraint.
In passing, make ErrorBuilder support building the error message more incrementally and use that to improve diagnostics for mismatched values with equality constraints.
This does some more work to the run_clang_tidy.py wrapper script, and runs an example pass.
"again" because it's really the proto fuzzer changes that broke it, it had been working before.
"mostly" because there's still an issue within the proto fuzzer that it can't find "port/protobuf.h", i.e. https://github.com/google/libprotobuf-mutator/tree/master/port, but I'm still hesitant to add an include path there.
We don't seem to have any need for `TypeOf*Type` types, and having them introduces the temptation to use them during type-checking, which would lead to types having different behavior when their type-of-type is `Type` versus when it's a more precise type. Remove these types for now.
If we later decide that we want each type literal to have a unique type, as we do for value literals, we can introduce a single value kind for that rather than one for each kind of type.
No changes to `TypeOfMemberName`, `TypeOfParameterizedEntityName`, and `TypeOfMixinPseudoType`, which are placeholders, not real types.
Add checking that a type only satisfies a constraint if it satisfies all of that constraint's equality and rewrite constraints.
Enforce the rule that `=` must be used in impls when specifying associated constant values rather than `==`.
Turn off the pre-#2173 single-step equality behavior. This is getting somewhat ahead of the approved design, but it's a one-line change to restore the old behavior.
Fix `CARBON_CHECK` to handle top-level `,`s in its argument, such as may happen in template argument lists, as this change introduces such a check.
There are lots of ways a declaration can be used before we have the information necessary to handle that use. Issue diagnostics for these.
Interleave declaration and type-checking of global declarations so that declaring a later declaration can depend on the results of type-checking an earlier one.
Incorporates tests added in #2266.
Fixes#1394, fixes#1395, fixes#1396.
Co-authored-by: pmqtt <51272730+pmqtt@users.noreply.github.com>
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
This change left a test broken and removed a fair amount of test coverage for unrelated features, and after further discussion it's not clear that this is the direction we want to go in.
This reverts commit 6cf2272bbe.
Implements basic support for rewrite constraints as proposed in #2173.
Support for associated constants and complex constraints in general is also made more robust: argument deduction now properly computes and substitutes witnesses, and interface declarations track a more correct description of the constraint that they introduce than the one we previously built.
Change explorer's handling of witnesses to track them wherever possible. Associated constant support needs witnesses to be available much more pervasively.
The main changes here are:
- `Substitute` now takes a set of bindings covering both `Value`s for `GenericBinding`s and `Witness`es for `ImplBinding`s, and substitutes both.
- Witnesses are now tracked within `ConstraintType`s. The `.Self` type has an `ImplBinding` that self-references from parts of the constraint to other parts of the constraint can use to access the witness for the constraint.
- The constraint type for an `impl` and for a `GenericBinding` are now stored in pre-substituted form, with references to the actual constrained type rather than symbolic references to `.Self`. This results in minor changes in diagnostic text.
Argument deduction still performs substitutions without remapping witnesses.
Instead of forming a `SymbolicWitness` that contains an `Expression` when we can't directly resolve a witness to an `impl`, form different kinds of `Witness` values for the various situations:
- A `BindingWitness` witnesses that a type implements a constraint by reference to an `ImplBinding`.
- A `ConstraintWitness` witnesses that a type implements a constraint by reference to witnesses for each of the impl constraints within the constraint.
- A `ConstraintImplWitness` witnesses that a type implements a constraint by reference to a larger constraint which contains that constraint as an impl constraint.
Remove `SymbolicWitness` values and `InstantiateImpl` expressions, which are now unused. In order to remove the final usage of `SymbolicWitness`, I fixed a TODO to give `Self` the proper type within an interface declaration. I don't think this is an observable change.
No functional change intended.
Previously we used an expression in some places and a `Witness` values in others. The eventual goal is to make `Witness` values behave like other symbolic values such as `NominalClassType`, but the first step is to consistently treat them like values rather than expressions.
No functionality change intended.
* Multiplication and division have the same priority.
* A new builtin interface DivWith is added.
* In some tests expecting a compilation error (syntax error), the error
message now says it is expecting SLASH or binary *.
* Replay changes from pre-force-push mixin branch
* Base MixinPseudoType off of the new InterfaceType
* Add more test cases.
Also removed an unnecessary check that would have already been
handled by the parser.
* WIP detect member clashes during mixing mixins
* Implement fuzzer changes
* Implement member name clash check when mixing mixins
* Modify parser and lexer for experimental mixin feature
* Add comments
* Update explorer/testdata/mixin/simple-mix-in-mixin.carbon
Co-authored-by: josh11b <josh11b@users.noreply.github.com>
* Update explorer/testdata/mixin/use-mixin-method-in-class-method.carbon
Co-authored-by: josh11b <josh11b@users.noreply.github.com>
* Make code review changes
Co-authored-by: josh11b <josh11b@users.noreply.github.com>
The most significant change here is that explorer now uses the chosen spelling
rather than the old `Bool` spelling. Also update a few documentation examples
and some skeletal design docs to use the chosen spelling.
Following #1191, add initial support for bitwise operators. Support for both
integer operations and for operator overloading via the interfaces specified in
#1191 is provided.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Allows unformed state for local variables. Reports a run-time error when an unformed local variable is used.
- Added declaration without initialization for local variables in the parser.
- Made the init expression of VariableDefinition optional.
- Expanded (alive, dead) to (uninitialized, alive, dead) in the Heap.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
We don't have overload resolution, so I've simply added PrintInt for now. But it's really tempting to turn __intrinsic_print into a total kludge function.
Basic support for declaring, specifying the values of, and using associated constants.
This is incomplete in various ways. For example, when checking whether a type satisfies a constraint, there is no check that its associated constants match those in the constraint, and name lookup into a value whose type is an associated constant is not supported yet.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
This PR implements the `returned var` for the explorer.
- Enabled `returned var` and `return var` syntax in lexer and parser.
- Split `Return` statement into `ReturnVar` and `ReturnExpression` to distinguish the two types of returns.
- Added logic in name resolution, type checking and interpretation to process `returned var` definition and `ReturnVar` statement.
This avoids the need to make copies of potentially large maps when
the same bindings are used in multiple values, such as when forming
a bound method value.
Type checking now stores information on a member access identifying the member that was accessed, not only its name. This parallels what we do for other similar constructs whose meaning is resolved by name lookup or type-checking, and will allow us to avoid redoing lookups in some cases during interpretation.
`.Self` is modeled as a new kind of expression, `DotSelfExpression`. Name resolution associates each occurrence of a `DotSelfExpression` with a generic binding, much like for an `IdentifierExpression`.
Both `:!` bindings and `where` expressions bring `.Self` into scope. The tentative intent is that if there are multiple `.Self`s in scope and they refer to different bindings, the result of using a `.Self` expression is an ambiguity error, but that is not implemented in this patch. Instead, like for `IdentifierExpression`s, we find the innermost enclosing definition of `.Self`.
`.Foo` expressions are rewritten to `.Self.Foo`, but this isn't enough to make them do anything useful, because associated constants aren't supported in general yet.
Adrien Leravat
Jon Ross-Perkins
Junhee Cho
Darshal Shettyandjosh11b
Zenong Zhang
Thejaswi Kadur