Re: [Pharo-users] is this valid smalltalk

On 4. 4. 2019 13:16, Roelof Wobben wrote:

Hello,

For a challenge of Exercism I need to check if some parenthes and brackets are balanced.

so for example

()  = true ([])  = true

but (])  is not true because the bracket has no opening bracket.

Now I wonder if I can premature end a #do:  like this

collection do: [:element | (condition with element) ifFalse: [^false]]

in pseudo code

is this a valid way to end the do ?

Not sure I understand your question properly, but yes, you can do this, it is called "non-local return" and is a known pattern in Smalltalk.

or is there a better way ?

(collection detect: [:element | (condition with element) not] ifNone: [sentinel]) == sentinel ifFalse: [ ^false ] for example does not force you to employ it, as well as (collection allSatisfy: [:element | (condition with element)]) ifFalse: [ ^false ]

Roelof

Herby