At 18:29 30.06.00 -0500, jchludzinski@worldkey.net wrote:

I'm writing some numerical code and need to know:

How would I accomplish a "break" (a la 'C') from a ST do-loop?

breaking out of a block isn't possible in Smalltalk. You can use "^" (return) to leave a block but then you'll not only leave the block but also return from the block's defining method.

Here's a trick to simulate breaking just from a block:

Add the following method to class BlockContext

valueWithExit ^ self value: [:result | ^ result]

Now use

[:exit | 1 to: 10 do: [:i | i = 5 ifTrue: [exit value: -1]]. 10] valueWithExit

and you'll see that this block will return "-1" not "10".

Use an exception?

might be another solution but frankly, I'd recommend to refactor your problem so that you either use

i := 1. done := false. [done or: [i = 10]] whileFalse: [...]

as a loop or that the block is implemented as a single method from which you can return then.

bye -- Stefan Matthias Aust // Bevor wir fallen, fallen wir lieber auf