• vincent <vincent.risi gmail.com> Jun 08 2011
• "Jonathan M Davis" <jmdavisProg gmx.com> Jun 08 2011
• simendsjo <simen.endsjo pandavre.com> Jun 08 2011

vincent <vincent.risi gmail.com> writes:

Cover handler for a statement or a block of statements.

I would like to suggest a method for defining code statement
covering. Some examp1es of a cover are as follows :-
  - try ... finally - this is defined in dotnet as a using
  - try ... (catch)+
  - cursor save and display others ... restore saved cursor

a possible syntax -

  cover hourglass(Application &app)
  {
    Cursor save = app.cursor;
	app.cursor = HOURGLASS_CURSOR;
	~ code ~
	app.cursor = save;
  }

usage could be something like -

  void function(Application &app)
  {
    hourglass(app)
    {
      ... // code to be run by cover
    }
  }

"Jonathan M Davis" <jmdavisProg gmx.com> writes:

On 2011-06-08 12:06, vincent wrote:
 Cover handler for a statement or a block of statements.
 
 I would like to suggest a method for defining code statement
 covering. Some examp1es of a cover are as follows :-
 - try ... finally - this is defined in dotnet as a using
 - try ... (catch)+
 - cursor save and display others ... restore saved cursor
 
 a possible syntax -
 
 cover hourglass(Application &app)
 {
 Cursor save = app.cursor;
 app.cursor = HOURGLASS_CURSOR;
 ~ code ~
 app.cursor = save;
 }
 
 usage could be something like -
 
 void function(Application &app)
 {
 hourglass(app)
 {
 ... // code to be run by cover
 }
 }


That would typically be done with either a struct with a destructor or with a 
scope statement.

- Jonathan M Davis

simendsjo <simen.endsjo pandavre.com> writes:

On 08.06.2011 21:09, Jonathan M Davis wrote:
 On 2011-06-08 12:06, vincent wrote:
 Cover handler for a statement or a block of statements.

 I would like to suggest a method for defining code statement
 covering. Some examp1es of a cover are as follows :-
 - try ... finally - this is defined in dotnet as a using
 - try ... (catch)+
 - cursor save and display others ... restore saved cursor

 a possible syntax -

 cover hourglass(Application&app)
 {
 Cursor save = app.cursor;
 app.cursor = HOURGLASS_CURSOR;
 ~ code ~
 app.cursor = save;
 }

 usage could be something like -

 void function(Application&app)
 {
 hourglass(app)
 {
 ... // code to be run by cover
 }
 }


 That would typically be done with either a struct with a destructor or with a
 scope statement.

 - Jonathan M Davis


To give Jonathan's answer an example.
import std.stdio;

void main() {

     class Cursor {
         string name = "regular";
     }

     class Application {
         private Cursor _cursor;

          property Cursor cursor() {
             return _cursor;
         }

          property void cursor(Cursor value) {
             writeln("setting cursor ", value.name);
             _cursor = value;
         }

         this() { _cursor = new Cursor(); }
     }

     auto app = new Application();

     auto HOURGLASS_CURSOR = new Cursor();
     HOURGLASS_CURSOR.name = "hourglass";

     writeln("try/finally:");

     auto save = app.cursor;
     try {
         app.cursor = HOURGLASS_CURSOR;
         writeln("code here");
     } finally {
         app.cursor = save;
     }

     writeln("\nor scope(exit):");

     {
         save = app.cursor;
         scope(exit) app.cursor = save;
         app.cursor = HOURGLASS_CURSOR;
         writeln("code here");
     }
}

Outputs

try/finally:
setting cursor hourglass
code here
setting cursor regular

or scope(exit):
setting cursor hourglass
code here
setting cursor regular