ExprDecimalPlaces

[Absolutionism]

Problem

There is no expression allowing users to get how many decimal places a number goes into. Also was requested in the linked issue.

Solution

Adds ExprDecimalPlaces allowing users to quickly and easily get how many decimal places a number goes into.

Testing Completed

ExprDecimalPlaces.sk

Supporting Information

N/A

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Completes: #7948
Related: none

[erenkarakal]

double.toString always contains a dot

[sovdeeth]

I fear this will have some weird behavior with floating point errors. For example:

If you have number accuracy high, it really does have that many decimals. But if number accuracy is set to like 2, or even 7, it will print 3.
I'm not sure this should be based off of the doublevalue.toString at all.

[Absolutionism]

I'm not sure this should be based off of the doublevalue.toString at all.

What do you suggest? I was originally going to make it:

"[the] number of decimal places of %numbers% [limited:with a (limit|cap) of %-integer%]
"[the] number of decimal places of %numbers% [unlimited:with no (limit|cap)]

So default behavior would use the number accuracy option in the config
limited would limit to the provided integer
unlimited no limit

[sovdeeth]

I'm not sure this should be based off of the doublevalue.toString at all.

What do you suggest? I was originally going to make it:

"[the] number of decimal places of %numbers% [limited:with a (limit|cap) of %-integer%]
"[the] number of decimal places of %numbers% [unlimited:with no (limit|cap)]

So default behavior would use the number accuracy option in the config limited would limit to the provided integer unlimited no limit

Well I think you should be using Skript.toString() to convert the number to a string, which will respect the number accuracy.
Alternatively, you can forgo a toString entirely and instead repeatedly divide by 10 until x % 1 is within epsilon of 0/1.
You should try both and see how well each works

[Absolutionism]

Alternatively, you can forgo a toString entirely and instead repeatedly divide by 10 until x % 1 is within epsilon of 0/1.

So something like this?

for (Number number : numbers.getArray(event)) {
	if (!(number instanceof Double doubleValue))
		continue;
	long decimalPlace = 0L;
	double x = Double.valueOf(doubleValue);
	while (Math.abs(x % 1) > 1e-9) {
		x /= 10;
		decimalPlace++;
	}
	decimalPlaces.add(decimalPlace);
}

[sovdeeth]

Alternatively, you can forgo a toString entirely and instead repeatedly divide by 10 until x % 1 is within epsilon of 0/1.

So something like this?

for (Number number : numbers.getArray(event)) {
	if (!(number instanceof Double doubleValue))
		continue;
	long decimalPlace = 0L;
	double x = Double.valueOf(doubleValue);
	while (Math.abs(x % 1) > 1e-9) {
		x /= 10;
		decimalPlace++;
	}
	decimalPlaces.add(decimalPlace);
}

yes but i should have said multiply not divide
and make sure you check for the mod result being like 0.99999999

[sovdeeth]

why have both i and decimalPlace?

also i don't think this limit thing would work very well. Take 1.00001. With accuracy set to 2, this would print as 1, but have 2 decimal places. I think you'll need to round the number to the limit first.

[sovdeeth]

needs tests for floating point error stuff like places of 0.3/0.1