The idea of a flat ban on #ifTrue:ifFalse: is ridiculous. Number>>abs ^self negative ifTrue: [self negated] ifFalse: [self]
Is there any better way to do this? Not really, you can only move the #ifTrue:ifFalse: somewhere else. The main argument against #ifTrue:ifFalse: is NOT TO USE IT FOR TYPE TESTS. If you want to do different things depending on the class of x, ask x to do it. (The irony is that in Smalltalk, #ifTrue:ifFalse: *is* in principle an object-oriented dispatch.) If you want to do different things depending on the state of x, and this requires revealing internal details that would not otherwise be revealed, ask x to do it. Two key ideas in software engineering are coupling (lots of interdependencies makes things hard to re-use) and cohesion (modules/types/classes should be "about" one thing). You have to balance the "use OO dispatch" idea against this: you have a method in class A that depends on an object of class B, and you don't want A to have to know too much about B, but on the other hand, you don't want B to have to depend too much on what A is up to. If it makes sense to have a B without any A around, then changes to A should not really require changes to B. So eliminating #ifTrue:ifFalse: from your code can make it WORSE. You have to THINK about each task and decide where it REALLY belongs. Is this bit of code entirely about B? Then it belongs in B. Is that bit of code about already public information concerning B and also tied to A's needs and wants? Then it belongs in A. And if that means using some sort of "if", go ahead! The Pharo 6 sources contain about 5800 classes and over 40000 ifTrue:/ifFalse:/ifNil:/ifNotNil: uses. The Dolphin core contains about 2100 clases and over 12600 ifs. My Smalltalk has about 13 ifs per class. Smalltalk/X (JV) has about 6500 classes and over 127000 ifs, nearly 20 per class. On Wed, 28 Nov 2018 at 05:41, Roelof Wobben <r.wob...@home.nl> wrote: > Hello, > > Yesterday I had a talk with luc frabresse about using if then. > He said if I understand it right, Its the best to not using a if then or > a ifTrue/ifFalse. > > Can anyone help me figure out how to rewrite this project so I will not > use the ifTrue in the basement function. > > my code so far can be found here : https://github.com/RoelofWobben/AOC2015 > > Roelof > > >
