Hi,
I cannot seem to figure out how I can add the 'when' keyword to BOO which should behave as an 'if'. I figure I could make a method, but then I cannot move the when around like I can with if. Any pointers would be appreciated.
-Mark
A:
This would be a job for a macro. From the page you linked to, it seems that Boo has syntactic macros.
As an aside note, why do you need an exact duplicate of an existing functionality?
Svante
2009-01-16 01:53:14
The page linked to was an edit :) I saw that and all but for the if functionality I was unable to get it to work.Reason why I want it is for a DSL (readability).
2009-01-16 12:29:33
+10
A:
This would do what you want:
import Boo.Lang.Compiler.Ast
import Boo.Lang.Compiler.MetaProgramming
macro when:
return [|
if $(when.Arguments[0]):
$(when.Block)
|]
x = 1
when x == 1:
print "x equals one"
when x == 2:
print "x equals two"
Btw, feel free to (also) ask on the Boo mailing-list to get (more) answers quicker ;)
Thanks, this is very helpful, now only if SO would send me an e-mail notifying you answered it.
2009-01-26 11:43:23
Hehe, well that's why I advised you to subscribe to the Boo mailing-list for your future questions (or just to keep up with the updates of the language ;) )
2009-01-30 05:30:15
Good answer.Note that if you also want to support "when... else", it'll get trickier.
Avish
2009-08-31 20:42:35