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Adrien LeravatandRichard Smith
46f4887cf7
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>
40 lines
826 B
Plaintext
40 lines
826 B
Plaintext
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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// AUTOUPDATE
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// RUN: %{explorer-run}
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// RUN: %{explorer-run-trace}
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// CHECK:STDOUT: Read var_c=1
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// CHECK:STDOUT: Read var_d=2
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// CHECK:STDOUT: Assign var_c=3
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// CHECK:STDOUT: Assign var_d=4
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// CHECK:STDOUT: result: 0
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package ExplorerTest api;
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base class C {
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var var_c: i32;
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}
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class D extends C {
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var var_d: i32;
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}
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fn Main() -> i32 {
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// Initialization
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var d: D = {.base = {.var_c= 1}, .var_d= 2};
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// Read
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Print("Read var_c={0}", d.var_c);
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Print("Read var_d={0}", d.var_d);
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// Assignment
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d.var_c = 3;
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d.var_d = 4;
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Print("Assign var_c={0}", d.var_c);
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Print("Assign var_d={0}", d.var_d);
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return 0;
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}
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