Hello [EMAIL PROTECTED]!
On 22-Gen-00, you wrote:
j> I have a general comment about this thread. It seems to me to
j> point up the difficulty of writing first-class control
j> structures in REBOL. I haven't seen in this thread (nor have I
j> been able to think of) an approach that actually behaves as
j> well as a native control structure.
I think it is feasible.
j> I get the following:
j>>> testcase2
j> 1 = 1
j> ** Script Error: result needs a value.
j> ** Where: result: do blk
j> due to the fact that print doesn't return a result:
j>>> foo: print 123
j> 123
j> ** Script Error: foo needs a value.
j> ** Where: foo: print 123
Can be fixed using:
set/any 'foo print 123
j> [EMAIL PROTECTED] wrote:
I prefer the version corrected by Ladislav.
j> Again, a nice piece of code, but look what happens with
j> paranoid1: func [a b] [
j> do-cases [
j> a <= 0 [return 0]
j> b <= 0 [return 0]
j> else [print "OK"]
j> ]
j> print "Computing now!"
j> ]
This can be handled by the function attribute 'throw. You can
write 'do-cases as:
do-cases: func [
"Executes the case whose condition is true"
[throw]
...
With 'throw any 'return or 'exit will be passed along to the
caller.
Regards,
Gabriele.
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