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[ACCELEO] Big integers [message #1791339]

Thu, 28 June 2018 08:39

Nicola Serreli

Messages: 26
Registered: July 2009

Junior Member

Hi,

I had some problems using integers bigger than 2^31.

Running the following code, it looks like Acceleo (OCL?) is able to handle 64bit integers,
using for them the acceleo type Integer, but the actual java class used to store them looks like to be Integer or Long (depending on the integer value).
The result is that some actions/commands may not work as expected, like the following ones:
* .oclIsKindOf(Integer) returns false for big (Long) values
* ->filter(Integer) removes big (Long) values
* ->sortedBy(v | -v) fails if there is at least one small (Integer) value and one big (Long) value, throwing a java.lang.ClassCastException (the result is an "OclInvalid" object)

----------------------------------
Here is an example

[query public powerOf2(x : Integer) : Integer =
if (x = 1) then
    2
else if (x > 1) then
    let new_x : Integer = x-1 in
    2 * powerOf2( new_x )
else
    -1
endif
endif
/]

[template public intTest(arg : OclAny) {
values  : Sequence(Integer) = Sequence(Integer) { 1 .. 70 };
results : Sequence(Integer) = values->collect(powerOf2());
}]
[file ('stdout', false, 'UTF-8')]

[for (x : Integer | values)]
2^[x/] = ( int ? [powerOf2(x).oclIsKindOf(Integer)/] ) -> [powerOf2(x)/] [if (
    (powerOf2(x) <> results->at(x))
)]different values[/if]

[/for]

Number of all computed values = [results->size()/] (including zeroes)
Number of all filtered values = [results->filter(Integer)->select(v : Integer | v<>0)->size()/]

Sort throws java.lang.ClassCastException -> [results->sortedBy(v | -v)/]

[/file]
[/template]

----------------------------------
Here are some lines of the output

...
2^30 = ( int ? true ) -> 1073741824
2^31 = ( int ? false ) -> 2147483648
...
2^62 = ( int ? false ) -> 4611686018427387904
2^63 = ( int ? false ) -> -9223372036854775808
2^64 = ( int ? true ) -> 0
...
Number of all computed values = 70 (including zeroes)
Number of all filtered values = 30

Sort throws java.lang.ClassCastException -> invalid

----------------------------------
Just a note: Acceleo has the type UnlimitedNatural, but, at the end, it still handles at most 64bit integers.
Some commands works, some other not.
* .oclIsKindOf(UnlimitedNatural) returns true for UnlimitedNatural, returns false for Integer, like literal values
* ->filter(UnlimitedNatural) keeps all UnlimitedNatural objects
* ->sortedBy(v | -v) fails if there is at least one small (<31bit) value and one big (>=31bit) value, throwing a java.lang.ClassCastException (the result is an "OclInvalid" object)
* literals depending on the context, the literals are Integer, so here and there acceleo complains that UnlimitedNatural is not an Integer (and viceversa)

----------------------------------
Any ideas/suggestion about how avoid this kind of problem, is really appreciated.

Best regards,
Nicola

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