Check in range precondition

Question

I like guava preconditions, but what I really need from it is one more method - check that the number is in range. Smt like this

//probably there should be checkStateInRange also
public static void checkArgumentInRange(double value, int min, int max) {
    if (value < min || value > max) {
        throw new IllegalArgumentException(String.format("%s must be in range [%s, %s]", value, min, max));
    }
}

I believe I'm not alone and it's a pretty common case. But such method doesn't exist. Is there any reasons to not put such methods in com.google.common.base.Preconditions?

P.S. Yes, I know that I can create new classes like Angle to put some restriction on values. — Stan Kurilin, Nov 21 '11 at 20:08
For one you would need 4 such methods to cover inclusive and exclusive boundary conditions. — rsp, Nov 21 '11 at 20:20
@rsp, correct. Actually, it's not so bad. Alternatively, we can introduce `Range` class. — Stan Kurilin, Nov 21 '11 at 20:23

score 8 · Accepted Answer · answered Nov 21 '11 at 20:32

There are quite a few reasons I'd say. Here are the main ones:

There's no standard Java exception type for "value out of range". Note that each of the Preconditions methods throws a specific exception type for what it checks: NullPointerException, IllegalArgumentException, IllegalStateException or IndexOutOfBoundsException. A generalized range check would have no exception more specific than IllegalArgumentException to throw.
checkArgument and checkState do everything you need. You can just write checkArgument(value >= min && value <= max, ...). It's simple and obvious what you're checking.

Additionally:

There are too many different combinations you might want here. Exclusive/inclusive bounds as @rsp mentions, etc.
It's limiting to only allow ints for the bounds, so you would really like to allow any Comparable there.
At this point you notice you're just checking if the value is contained in a Range.

`Range` class with `contains` method is a really good point. Thanks a lot. — Stan Kurilin, Nov 21 '11 at 20:40

score 6 · Answer 2 · answered Nov 21 '11 at 20:33

6

I think you can get very close by using checkArgument():

checkArgument(min < value && value < max, "%s must be in range [%s, %s]", value, min, max);

which, if you add the message strings to your own constant definitions, isn't much boilerplate and has all the flexibility you need.

answered Nov 21 '11 at 20:33

rsp

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[ and ] is closed range. So, the condition "min < value && value < max" should represent to "(%s, %s)". ref. https://github.com/google/guava/wiki/RangesExplained – Namo Feb 03 '21 at 07:11

Check in range precondition

2 Answers2

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