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Is there a way to assign calculated values in guards to variables?
Thu, 2009-01-15, 01:19
Howdy,
In pattern matching, I can assign the matched value to a variable:
{ case f @ Foo(_) => f.toString}
I'd like to be able to assign a computed value from a guard as well. For example:
{ case Some(id) if (record @ findRecord(id)).isDefined => record.name}
Is there any way to do this?
Thanks,
David
--
Lift, the simply functional web framework http://liftweb.net
Collaborative Task Management http://much4.us
Follow me: http://twitter.com/dpp
Git some: http://github.com/dpp
In pattern matching, I can assign the matched value to a variable:
{ case f @ Foo(_) => f.toString}
I'd like to be able to assign a computed value from a guard as well. For example:
{ case Some(id) if (record @ findRecord(id)).isDefined => record.name}
Is there any way to do this?
Thanks,
David
--
Lift, the simply functional web framework http://liftweb.net
Collaborative Task Management http://much4.us
Follow me: http://twitter.com/dpp
Git some: http://github.com/dpp
Wed, 2009-01-21, 23:27
#2
Re: Is there a way to assign calculated values in guards to va
There's a way if you decide to try the Extractor way but you will not have the same syntax and it's less flexible.Good luck!Stephane
On Wed, Jan 21, 2009 at 10:39 PM, martin odersky <martin.odersky@epfl.ch> wrote:
On Wed, Jan 21, 2009 at 10:39 PM, martin odersky <martin.odersky@epfl.ch> wrote:
On Thu, Jan 15, 2009 at 1:19 AM, David Pollak
<feeder.of.the.bears@gmail.com> wrote:
> Howdy,
> In pattern matching, I can assign the matched value to a variable:
> {
> case f @ Foo(_) => f.toString
> }
> I'd like to be able to assign a computed value from a guard as well. For
> example:
> {
> case Some(id) if (record @ findRecord(id)).isDefined => record.name
> }
> Is there any way to do this?
Just to confirm the silence on the list since then: no, there's no way
to do this.
Cheers
-- Martin
Thu, 2009-01-22, 00:47
#3
Re: Is there a way to assign calculated values in guards to va
On Wed, Jan 21, 2009 at 2:21 PM, Stephane Le Dorze <stephane.ledorze@gmail.com> wrote:
There's a way if you decide to try the Extractor way but you will not have the same syntax and it's less flexible.Good luck!
Slick... I hadn't thought of this. It solves the problem. Thanks!
Stephane
On Wed, Jan 21, 2009 at 10:39 PM, martin odersky <martin.odersky@epfl.ch> wrote:
On Thu, Jan 15, 2009 at 1:19 AM, David Pollak
<feeder.of.the.bears@gmail.com> wrote:
> Howdy,
> In pattern matching, I can assign the matched value to a variable:
> {
> case f @ Foo(_) => f.toString
> }
> I'd like to be able to assign a computed value from a guard as well. For
> example:
> {
> case Some(id) if (record @ findRecord(id)).isDefined => record.name
> }
> Is there any way to do this?
Just to confirm the silence on the list since then: no, there's no way
to do this.
Cheers
-- Martin
--
Lift, the simply functional web framework http://liftweb.net
Collaborative Task Management http://much4.us
Follow me: http://twitter.com/dpp
Git some: http://github.com/dpp
On Thu, Jan 15, 2009 at 1:19 AM, David Pollak
wrote:
> Howdy,
> In pattern matching, I can assign the matched value to a variable:
> {
> case f @ Foo(_) => f.toString
> }
> I'd like to be able to assign a computed value from a guard as well. For
> example:
> {
> case Some(id) if (record @ findRecord(id)).isDefined => record.name
> }
> Is there any way to do this?
Just to confirm the silence on the list since then: no, there's no way
to do this.
Cheers