The “Kent Beck approved solutions” here are two:
1) To use a dictionary (or ordered dictionary).
case := OrderedDictionary newFromPairs: {
[ cond ]. [ do ].
[ cond ]. [ do ].
[ true ]. [ otherwise do ] }
case keysAndValuesDo: [ :cond :do |
(cond value: expression) ifTrue: [
“you need to break here"
^ do value ].
2) To use a “case method”
caseMethod: expression
expression = cond1 ifTrue: [ ^ do1 ].
expression = cond2 ifTrue: [ ^ do2 ].
^ otherwise
Personally, I prefer the second one because is more concise, performant and
easy to understand.
Esteban
> On 28 Dec 2019, at 11:58, Dennis Schetinin <chae...@gmail.com> wrote:
>
> It would be an overkill to do it for this particular case, but Smalltalk
> makes it possible to implement a case-like construction:
>
> [ expression ]
> when: [ :value | condition1 ] do: [-0do :value | ... ];
> when: [ :value | condition2 ] do: [ :value | ... ];
> otherwiseDo: [ :value | ... ];
> evaluate
>
>
> I am sure, something like this has been implemented already somewhere (maybe
> in Squeak?). Still not sure it is practical as compared to simple if-s, and
> for sure not widely used :)
> ...On the other hand, sometimes the case-like construction can be considered
> a more intension-revealing style.
>
> пт, 27 дек. 2019 г., 22:18 Roelof Wobben via Pharo-users
> <pharo-users@lists.pharo.org <mailto:pharo-users@lists.pharo.org>>:
> Hello,
>
> Im trying to solve a challenge from exercism where I have to calculate the
> points somehow gets on a very simple darts board.
>
> I solved it like this :
>
>
> scoreX: anInteger y: anInteger2
> | distance |
> distance := (anInteger squared + anInteger2 squared) sqrt.
> distance > 10
> ifTrue: [ ^ 0 ].
> distance > 5
> ifTrue: [ ^ 1 ].
> distance > 1
> ifTrue: [ ^ 5 ].
> ^ 10
>
>
> but now I use three if then and I think it's ugly code.
>
> Is there a way I can make it more the smalltalk way ?
>
>
> Regards,
>
> Roelof
>
