[Olena-patches] 503: More on SCOOP methods in Static tour

https://svn.lrde.epita.fr/svn/oln/trunk/static ChangeLog | 18 +++++++++++++++++ tests/tour.cc | 61 +++++++++++++++++++++++++++++++++++++++++++++------------- 2 files changed, 66 insertions(+), 13 deletions(-) Index: ChangeLog from Roland Levillain &lt;roland(a)lrde.epita.fr&gt; More on SCOOP methods in Static tour. * tests/tour.cc (dynamic_hierarchy::A::foo) (dynamic_hierarchy::A::bar, dynamic_hierarchy::B::foo) (dynamic_hierarchy::B::bar, dynamic_hierarchy::C::foo): Return an int value. (static_hierarchy_with_methods::A::foo) (static_hierarchy_with_methods::A::impl_foo) (static_hierarchy_with_methods::A::bar) (static_hierarchy_with_methods::B::impl_foo) (static_hierarchy_with_methods::B::impl_bar) (static_hierarchy_with_methods::C::impl_foo): Likewise. (static_hierarchy_with_methods): Add comments. (static_hierarchy_with_methods::test): New. (main): Call it. Index: tests/tour.cc --- tests/tour.cc (révision 502) +++ tests/tour.cc (copie de travail) @@ -75,25 +75,25 @@ struct A { // A virtual method. - virtual void foo() { /* ... */ } + virtual int foo() { return 1; } // A virtual pure method. - virtual void bar() = 0; + virtual int bar() = 0; }; // `B' is a concrete class. struct B { // A redefined method. - virtual void foo() { /* ... */ } + virtual int foo() { return 2; } // `B::bar' is defined. - virtual void bar() { /* ... */ } + virtual int bar() { return 3; } }; // `C' is a concrete class. struct C { // `B::foo' is redefined. - virtual void foo() { /* ... */ } + virtual int foo() { return 4; } }; } // end of namespace dynamic_hierarchy @@ -338,9 +338,22 @@ // Methods. // // --------- // -// Add the methods. +/* We have laid down the foundations of our classes. Now it's time to + add some methods. -// FIXME: Comments. + Unlike classic C++, SCOOP doesn't use the `virtual' keyword to + define polymorphic methods. As SCOOP performs a static resolution + of method calls, it can't rely on `virtual' (which is dynamic per + se). Instead, a manual dispatch of method call is used: each + polymorphic method is turned into a facade, and there is one + implementation per class defining this method actually. The facade + retrieves the exact type of the object, and calls the + implementation corresponding to this type. A SCOOP abstract + polymorphic method (the equivalent of C++ ``virtual pure'' method) + has no implementation in the class where its facade is defined. + + The convention is to name `impl_m' the implementation(s) of the + facade `m'. */ namespace static_hierarchy_with_methods { @@ -351,12 +364,12 @@ /* Facade of a statically-dispatched method. Notice there is no `virtual' keyword: the (static) dispatch is done manually through the delegation to impl_foo. */ - void foo() { this->exact().impl_foo(); } + int foo() { return this->exact().impl_foo(); } // Implementation of the method. - void impl_foo() { /* ... */ } + int impl_foo() { return 1; } // A ``virtual'' pure (i.e., abstract) method. - void bar() { this->exact().impl_bar(); } + int bar() { return this->exact().impl_bar(); } // (No `impl_bar', since bar is abstract.) }; @@ -364,20 +377,41 @@ struct B : public A< stc_find_exact(B, Exact) > { // A redefined method. - void impl_foo() { /* ... */ } + int impl_foo() { return 2; } // B::bar (implementation) is defined. - void impl_bar() { /* ... */ } + int impl_bar() { return 3; } }; struct C : public B<C> { // Redefinition. - void impl_foo() { /* ... */ } + int impl_foo() { return 4; } }; } // end of namespace static_hierarchy_with_methods +namespace static_hierarchy_with_methods +{ + + void test() + { + C c; + assert (c.foo() == 4); + assert (c.bar() == 3); + + B<C>& b = c; + assert (b.foo() == 4); + assert (b.bar() == 3); + + A<C>& a = c; + assert (a.foo() == 4); + assert (a.bar() == 3); + } + +} // end of namespace static_hierarchy_with_methods + + // FIXME: Introduce static checks of methods (kind of concept checking). @@ -385,6 +419,7 @@ int main() { static_hierarchy_with_any::test(); + static_hierarchy_with_methods::test(); } /* References: