Using the switch(true) pattern in JavaScript

Re:Using the switch(true) pattern in JavaScript by jhgb on Monday April 12, 2021 @05:53PM (#26785659)

Instead of

    function check(x) {
        if (!test1 (x))   return false;
        if (!test2 (x))   return false;
        if (!test3 (x))   return false;
        if (!test4 (x))   return false;
        return true;
    }

why wouldn't you do something along the lines of

    (every (lambda (f) (funcall f x)) (list #'test1 #'test2 #'test3 #'test4a))

or whatever is the equivalent in your preferred language?

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Re:Using the switch(true) pattern in JavaScript by wvenable on Monday April 12, 2021 @06:03PM (#26785743)

The tests are rarely that simple or regular.

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Re:Using the switch(true) pattern in JavaScript by jhgb on Monday April 12, 2021 @06:25PM (#26785943)

Isn't that exactly the reason to put them somewhere else?

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Re:Using the switch(true) pattern in JavaScript by wvenable on Monday April 12, 2021 @06:30PM (#26785995)

No, I just mean the actual tests might be something like:

    if (user == null) return false;
    if (IsCompleted(user)) return true;
    if (action == null) return false;
    if (value < 0 || value > 100) return false;

You're not usually just passing a single value to a bunch of "test" functions.

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Re:Using the switch(true) pattern in JavaScript by jhgb on Monday April 12, 2021 @08:18PM (#26786740)

Well, the way it was written, I was assuming that conditions to be satisfied had separate named predicates (although combinators could alleviate even some of these things).

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