xsharp.eu • HELP please - syntax for new class ...... >>
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HELP please - syntax for new class ...... >>

Posted: Sat Mar 18, 2017 12:21 pm
by Phil Hepburn
Hi guys,

Can anyone please suggest some X# syntax to express the following C# class ? :-
HelpForum_01.jpg
HelpForum_01.jpg (56.26 KiB) Viewed 637 times
And for those how give me a hard time over images V text, here is some text to use :-

public abstract class GenericDataSourceBase<DSO, VMO, MAPPER, DAL> : IGenericDataSource<VMO>
where MAPPER : IGenericVMMapper<DSO, VMO>, new()
where VMO : IDSObjectWithState
where DSO : IDSObjectWithState
where DAL : IGenericDAL<DSO>, new()
{
// method to get a single object by its primary key
public virtual DSResult<VMO> GetData(int dataid)

Just to keep you in the picture, the translation of Nick friend's C# Generic Data, EF6 and MVVM sample app is progressing nicely. A lot of work before we seen any tangible results however ;-0)

TIA,
Phil.

HELP please - syntax for new class ...... >>

Posted: Sat Mar 18, 2017 3:08 pm
by robert
Phil,

Look at: https://www.xsharp.eu/help/class.html
and
https://www.xsharp.eu/help/generic-types.html

for the syntax.

It will become something like

Code: Select all

CLASS GenericDataSourceBase<DSO, VMO, MAPPER, DAL> IMPLEMENTS IGenericDataSource ;
   WHERE MAPPER IS IGenericVMMapper<DSO, VMO>, NEW();
   WHERE VMO IS IObjectWithState ;
   WHERE DSO IS IObjectWithState ;
   WHERE DAL IS IGenericDAL<DSO>, New()

.
.
END CLASS
Robert

HELP please - syntax for new class ...... >>

Posted: Sat Mar 18, 2017 3:34 pm
by Phil Hepburn
Thanks Robert,

Got me on my way, and past the parser and compiler.

Out of interest the image shows the last line has 'IS' and not 'is'.
parserCS_01.jpg
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This is simply because when I tried to Build I got an error message regarding the same.

When I just there now tried to regenerate the error message to show you, the 'is' compiled OK !?

Here it is :-
parserCS_02.jpg
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I have more C# I need help with - but later. Am going to see some sport on my new Sky Sport 'Q' box.

Thanks again for your help so far.

Oh! I thought 'new()' was a C# way of instantiating - what does it mean to X# guys ?

Cheers,
Phil.

HELP please - syntax for new class ...... >>

Posted: Sat Mar 18, 2017 3:43 pm
by Phil Hepburn
Thanks Robert,

I am getting there okay it seems - BUT - there is some strange C# code (to me) in this code to deal with Generics and Nicks' data.

Can you help me with this :-
syntaxCS_03.jpg
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I have made an attempt as seen below :-
syntaxCS_04.jpg
syntaxCS_04.jpg (99.07 KiB) Viewed 637 times
And so you can have text to work with below is both the X# and the original C# :-

============================================================================
public virtual method GetDataAsync(dataid as int) as Task<DSResult<VMO>>

return Task.Factory.StartNew<DSResult<VMO>>( { || ;
local result as DSResult<VMO>
try
local implied dal := DAL{}
local efdata := dal.DALGetData(dataid) as DSResult<DSO>

if (efdata.Result == DSResultType.Success)
local implied mapper := MAPPER{}
result := DSResult<VMO>{mapper.DSOtoVMO(efdata.Cargo)}
else
result := DSResult<VMO>{efdata.Result}
endif
catch e as Exception
result := DSResult<VMO>{DSResultType.Otherfailure, e}
end try
return result
} )
return result

========================================================================
public virtual Task<DSResult<VMO>> GetDataAsync(int dataid)
{
return Task.Factory.StartNew<DSResult<VMO>>(() =>
{
DSResult<VMO> result;
try
{
DAL dal = new DAL();
DSResult<DSO> efdata = dal.DALGetData(dataid);
if (efdata.Result == DSResultType.Success)
{
MAPPER mapper = new MAPPER();
result = new DSResult<VMO>(mapper.DSOtoVMO(efdata.Cargo));
}
else
{
result = new DSResult<VMO>(efdata.Result);
}
}
catch (Exception e)
{
result = new DSResult<VMO>(DSResultType.Otherfailure, e);
}
return result;
});
}Cheers,
==========================================================================================

TIA,

Phil.

HELP please - syntax for new class ...... >>

Posted: Sat Mar 18, 2017 5:34 pm
by Chris
Hi Phil,

Just remove the ";" from the end of the first "return" line (3rd line of those you posted). All that code that follows the return statement is an anonymous method and we have decided that anonymous method's lines should not be separated with ";" (otherwise you would have to add a semicolon at the end of _every_ line).

Also remove the final "RETURN" (it's redundant, that anonymous method is what is already is being returned by the GetDataAsync method) and it should compile fine.

And yes, providing the source code was extremely helpful in testing my suggestions and making sure I am not saying something stupid :)

Chris

HELP please - syntax for new class ...... >>

Posted: Sat Mar 18, 2017 7:56 pm
by Phil Hepburn
Thanks Chris,

Seems to compile fine and give no red lines, wavy or straight ;-0)

I will be back with another small syntax issue or two in the morning.

But what you have just put straight for me I can also apply to a few more methods and new class or two, so BIG thanks !

Cheers,
Phil.

HELP please - syntax for new class ...... >>

Posted: Sat Mar 18, 2017 8:04 pm
by Phil Hepburn
Hi again Chris,

Here is another code syntax snippet I will needs in the morning - original C# first :-
ChrisSyntax2_01.jpg
ChrisSyntax2_01.jpg (59.18 KiB) Viewed 637 times
And now my not very clever attempt at X# :-
ChrisSyntax2_02.jpg
ChrisSyntax2_02.jpg (57.06 KiB) Viewed 637 times
And finally some of my code for you to copy and paste :-

============================================================
public interface IGenericDataSource<VMO>
GetData(dataid as int) as DSResult<VMO>
FetchDataList() as DSResult<List<VMO>>
UpdateDB(DataAction edittype, VMO dataobject) as DSResult<VMO>

GetDataAsync(dataid as int) as Task<DSResult<VMO>>
FetchDataListAsync() as Task<DSResult<List<VMO>>>
UpdateDBAsync(edittype as DataAction, dataobject as VMO) as Task<DSResult<VMO>>
end interfaceCheers,
========================================================================================

Once again, if I get an answer to this I will be able to apply it in many places ;-)

Best regards,
Phil.

HELP please - syntax for new class ...... >>

Posted: Sun Mar 19, 2017 2:56 am
by Chris
Hi Phil,

You just need to put the METHOD keyword before each method name in the interface definition. Also adjust the parameters of the UpdateDB() method (they currently use the c# syntax in you sample) and it should compile fine.

Chris

HELP please - syntax for new class ...... >>

Posted: Mon Mar 20, 2017 10:43 am
by Phil Hepburn
Chris,

thanks, done, and now things are looking OK.

May be back to you again soon ;-0)

Fingers crossed,
Phil.
Wales, UK.

HELP please - syntax for new class ...... >>

Posted: Mon Mar 20, 2017 2:37 pm
by robert
Phil

Code: Select all

New()
is just an indication that the type has a public constructor without parameters.
We copied the C# term because we were not very creative at that time.

We should have probably changed it to

Code: Select all

New{}
in stead but I am sure that people would have more problems then converting C# code to X#. It is already complicated enough at this moment, especially for generic classes.

Maybe we should create a small tool that takes a block of C# code, parses it with Roslyn into a parse tree and then spits out X# code?

Robert