How to translate C# 'readonly' keyword into D
I'm a C# programmer, when I apply IoC pattern I use readonly
keyword
(http://msdn.microsoft.com/en-us/library/acdd6hb7%28v=vs.71%29.aspx)
in this manner:
:// C# code
:interface IFoo {
: void Fun();
:}
:
:class Foo: IFoo {
: void Fun() {...}
:}
:class Bar {
: private readonly IFoo foo;
: // inject IFoo into Bar
: Bar(IFoo foo) {
:// assert(foo != null);
:this.foo = foo;
: }
: void Gun() {
:// foo = new Foo(); ERROR: foo is readonly!
:foo.Fun();
: }
:}
Can someone help me to translate readonly IFoo foo; so that the
dmd compiler raises an error when I write foo = new Foo(); ?
I try:
:// D code
:interface IFoo {
: void fun();
:}
:
:class Foo: IFoo {
: void fun() {
: writeln(fun...);
: }
:}
:
:class Bar {
: private const IFoo service;
: this(const IFoo service) {
: this.service = service;
: }
:
: void gun() {
: service.fun();
: }
:}
:unittest {
: const(IFoo) s = new Foo;
: auto bar = new Bar(s);
: bar.gun();
:}
but the compiler complains:
Error: function main.IFoo.fun () is not callable using argument
types () const
Re: How to translate C# 'readonly' keyword into D
On Monday, 4 February 2013 at 09:02:31 UTC, o3o wrote:
I'm a C# programmer, when I apply IoC pattern I use readonly
keyword
(http://msdn.microsoft.com/en-us/library/acdd6hb7%28v=vs.71%29.aspx)
in this manner:
:// C# code
:interface IFoo {
: void Fun();
:}
:
:class Foo: IFoo {
: void Fun() {...}
:}
:class Bar {
: private readonly IFoo foo;
: // inject IFoo into Bar
: Bar(IFoo foo) {
:// assert(foo != null);
:this.foo = foo;
: }
: void Gun() {
:// foo = new Foo(); ERROR: foo is readonly!
:foo.Fun();
: }
:}
Can someone help me to translate readonly IFoo foo; so that
the dmd compiler raises an error when I write foo = new
Foo(); ?
I try:
:// D code
:interface IFoo {
: void fun();
:}
:
:class Foo: IFoo {
: void fun() {
: writeln(fun...);
: }
:}
:
:class Bar {
: private const IFoo service;
: this(const IFoo service) {
: this.service = service;
: }
:
: void gun() {
: service.fun();
: }
:}
:unittest {
: const(IFoo) s = new Foo;
: auto bar = new Bar(s);
: bar.gun();
:}
but the compiler complains:
Error: function main.IFoo.fun () is not callable using argument
types () const
In D, everything accessible from const is also const. You
specifically state that you will not modify your IFoo instance.
But then you call foo(). foo() in turn isn't marked as const, so
this can modify IFoo, and thus break const.
So.. Every method you call through a const instance must also be
const, otherwise you have the ability to change something that
should be a constant.
Re: How to translate C# 'readonly' keyword into D
On Monday, 4 February 2013 at 10:26:55 UTC, simendsjo wrote:
On Monday, 4 February 2013 at 09:02:31 UTC, o3o wrote:
I'm a C# programmer, when I apply IoC pattern I use
readonly keyword
(http://msdn.microsoft.com/en-us/library/acdd6hb7%28v=vs.71%29.aspx)
in this manner:
:// C# code
:interface IFoo {
: void Fun();
:}
:
:class Foo: IFoo {
: void Fun() {...}
:}
:class Bar {
: private readonly IFoo foo;
: // inject IFoo into Bar
: Bar(IFoo foo) {
:// assert(foo != null);
:this.foo = foo;
: }
: void Gun() {
:// foo = new Foo(); ERROR: foo is readonly!
:foo.Fun();
: }
:}
Can someone help me to translate readonly IFoo foo; so that
the dmd compiler raises an error when I write foo = new
Foo(); ?
I try:
:// D code
:interface IFoo {
: void fun();
:}
:
:class Foo: IFoo {
: void fun() {
: writeln(fun...);
: }
:}
:
:class Bar {
: private const IFoo service;
: this(const IFoo service) {
: this.service = service;
: }
:
: void gun() {
: service.fun();
: }
:}
:unittest {
: const(IFoo) s = new Foo;
: auto bar = new Bar(s);
: bar.gun();
:}
but the compiler complains:
Error: function main.IFoo.fun () is not callable using
argument types () const
In D, everything accessible from const is also const. You
specifically state that you will not modify your IFoo instance.
But then you call foo(). foo() in turn isn't marked as const,
so this can modify IFoo, and thus break const.
So.. Every method you call through a const instance must also
be const, otherwise you have the ability to change something
that should be a constant.
So this works:
interface IFoo {
void fun() const;
}
class Foo : IFoo {
void fun() const {}
}
class Bar {
private const IFoo service;
this(const IFoo service) {
this.service = service;
}
void gun() {
service.fun();
}
}
unittest {
const s = new Foo();
auto bar = new Bar(s);
bar.gun();
}
void main() {}
Re: How to translate C# 'readonly' keyword into D
On 2013-02-04 10:02, o3o wrote:
I'm a C# programmer, when I apply IoC pattern I use readonly keyword
(http://msdn.microsoft.com/en-us/library/acdd6hb7%28v=vs.71%29.aspx) in
this manner:
:// C# code
:interface IFoo {
: void Fun();
:}
:
:class Foo: IFoo {
: void Fun() {...}
:}
:class Bar {
: private readonly IFoo foo;
: // inject IFoo into Bar
: Bar(IFoo foo) {
:// assert(foo != null);
:this.foo = foo;
: }
: void Gun() {
:// foo = new Foo(); ERROR: foo is readonly!
:foo.Fun();
: }
:}
Can someone help me to translate readonly IFoo foo; so that the dmd
compiler raises an error when I write foo = new Foo(); ?
The closest would probably be defining a property with only a getter:
class Bar
{
private IFoo foo_;
private @property foo () { return foo_; }
this (IFoo foo)
{
foo_ = foo;
}
}
You can still change the foo_ variable.
--
/Jacob Carlborg
Re: How to translate C# 'readonly' keyword into D
On Monday, 4 February 2013 at 10:26:55 UTC, simendsjo wrote:
[cut]
So.. Every method you call through a const instance must also
be const, otherwise you have the ability to change something
that should be a constant.
Thanks simendsjo, now I get it...
So, let me continue the example (I remove const for
simplicity)...
I would like check that bar.gun() call fun() function from IFoo
unittest {
auto foo = new MockIFoo(); //Will not compile.Mock doesn't
(yet) exist
auto bar = new Bar(foo);
bar.gun();
foo.Received().fun(); // pass if 'fun' was called
}
void main() {}
In other words, I need a mock object like nsubstitute
(http://nsubstitute.github.com/help/getting-started/) or moq
(http://code.google.com/p/moq/)
In your old post
http://forum.dlang.org/thread/il29hs$2svt$1...@digitalmars.com
you were asking for mocking frameworks...do you found any
solution?
Thanks
Re: How to translate C# 'readonly' keyword into D
First, AFAIK, there is no equivalent of C# readonly in D,
despite the fact that D uses 3 keywords for various kinds of
immutability.
Second, here you can find a mocking library for D:
http://www.dsource.org/projects/dmocks/wiki/DMocks
On Monday, 4 February 2013 at 13:35:24 UTC, o3o wrote:
On Monday, 4 February 2013 at 10:26:55 UTC, simendsjo wrote:
[cut]
So.. Every method you call through a const instance must also
be const, otherwise you have the ability to change something
that should be a constant.
Thanks simendsjo, now I get it...
So, let me continue the example (I remove const for
simplicity)...
I would like check that bar.gun() call fun() function from IFoo
unittest {
auto foo = new MockIFoo(); //Will not compile.Mock
doesn't (yet) exist
auto bar = new Bar(foo);
bar.gun();
foo.Received().fun(); // pass if 'fun' was called
}
void main() {}
In other words, I need a mock object like nsubstitute
(http://nsubstitute.github.com/help/getting-started/) or moq
(http://code.google.com/p/moq/)
In your old post
http://forum.dlang.org/thread/il29hs$2svt$1...@digitalmars.com
you were asking for mocking frameworks...do you found any
solution?
Thanks
Re: How to translate C# 'readonly' keyword into D
On 2013-02-04 14:35, o3o wrote:
So, let me continue the example (I remove const for simplicity)...
I would like check that bar.gun() call fun() function from IFoo
unittest {
auto foo = new MockIFoo(); //Will not compile.Mock doesn't (yet)
exist
auto bar = new Bar(foo);
bar.gun();
foo.Received().fun(); // pass if 'fun' was called
}
void main() {}
The syntax for template instantiation is:
auto foo = new Mock!(IFoo)();
--
/Jacob Carlborg
