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
