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Re: constructors with mix of params and Map
by Aaron Digulla
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Jochen Theodorou schrieb:
>> That was exactly my point. The initial Groovy example was not under
>> fixed ordering rules, and I have argumented that we should use a fixed
>> order rule if we want to support this feature.
>
> we already have one. named arguments are in a map in the first argument,
> additional positional arguments can be used by a vargs part...
>
> for example
>
> def foo(named=[:], arg1, arg2, Object.. args) {}
>
> well it is working only locally , because Groovy seems to have a little
> problem that I have to fix first.. but anyway, that is how it could be used
Will this work:
args=[a:'x']
foo(args, 1,2)
? I.e. is "args" assigned to "named" in this case?
Also something I'd like to see: Default values for parameters:
def foo(named=[:], arg1, arg2=5, Object... args) {}
Implementation:
Internally, all parameters with default values will be passed via a
varargs part. If there alreay is a varargs part, then they are added at
the front of the varargs array which is automatically created.
If the varargs array has a type != Object, then internally it will be
Object and the original variable arguments are then copied into a new
array with the correct type. Example:
def foo(named=[:], arg1, arg2=5, String... args) {}
will be converted into:
Object foo(Map names, Object arg1, Object... _args) {
// Handle arguments with default values
Object arg2; // Use object since no type was specified
if (_args.length > 0) {
arg2 = _args[0];
} else {
arg2 = new Integer(5); // Maybe extract constant here
// (saves a few cycles)
}
// Create expected varargs
int len = Math.min(0, _args.length - 1);
String[] args = new String[len];
System.arraycopy (_args, 1, args, 0, len);
// Original code follows here
}
(from the top of my head but you get the idea).
Regards,
--
Aaron "Optimizer" Digulla a.k.a. Philmann Dark
"It's not the universe that's limited, it's our imagination.
Follow me and I'll show you something beyond the limits."
http://www.pdark.de/
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To unsubscribe from this list please visit:
http://xircles.codehaus.org/manage_email
>> That was exactly my point. The initial Groovy example was not under
>> fixed ordering rules, and I have argumented that we should use a fixed
>> order rule if we want to support this feature.
>
> we already have one. named arguments are in a map in the first argument,
> additional positional arguments can be used by a vargs part...
>
> for example
>
> def foo(named=[:], arg1, arg2, Object.. args) {}
>
> well it is working only locally , because Groovy seems to have a little
> problem that I have to fix first.. but anyway, that is how it could be used
Will this work:
args=[a:'x']
foo(args, 1,2)
? I.e. is "args" assigned to "named" in this case?
Also something I'd like to see: Default values for parameters:
def foo(named=[:], arg1, arg2=5, Object... args) {}
Implementation:
Internally, all parameters with default values will be passed via a
varargs part. If there alreay is a varargs part, then they are added at
the front of the varargs array which is automatically created.
If the varargs array has a type != Object, then internally it will be
Object and the original variable arguments are then copied into a new
array with the correct type. Example:
def foo(named=[:], arg1, arg2=5, String... args) {}
will be converted into:
Object foo(Map names, Object arg1, Object... _args) {
// Handle arguments with default values
Object arg2; // Use object since no type was specified
if (_args.length > 0) {
arg2 = _args[0];
} else {
arg2 = new Integer(5); // Maybe extract constant here
// (saves a few cycles)
}
// Create expected varargs
int len = Math.min(0, _args.length - 1);
String[] args = new String[len];
System.arraycopy (_args, 1, args, 0, len);
// Original code follows here
}
(from the top of my head but you get the idea).
Regards,
--
Aaron "Optimizer" Digulla a.k.a. Philmann Dark
"It's not the universe that's limited, it's our imagination.
Follow me and I'll show you something beyond the limits."
http://www.pdark.de/
---------------------------------------------------------------------
To unsubscribe from this list please visit:
http://xircles.codehaus.org/manage_email
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