7.2.2 Fixnums🔗ℹ

A fixnum is an integer that fits into a range that has a specialized representation. This range depends on the architecture’s word size and Racket implementation, but it corresponds to integers that fit into a two’s complement representation using either 30, 31, 61, or 63 bits. In some cases, using functions and operators from rhombus/fixnum can reduce run time, but performance improvements (if any) may require unsafe mode via use_unsafe.

The functions exported by rhombus/fixnum explicitly require fixnum arguments and produce fixnum results.

Some operations, like <, statically specialize for performance when all arguments have static information for the Fixnum annotation. There is no performance difference between that inferred specialization and these operators, and a conversion is inferred only when the result value is the same for unspecialized and fixnum-specific operations.

Two fixnums that are the same according to == are also the same according to ===.

The fixnum.bits.logical.(>>) operator is like fixnum.bits.(>>), but it fills high bits with 0 instead of the fixnum’s sign bit.

A fixnum array potentially provides better performance than a normal array of fixnums, because the elements are known to be fixnums without a check on access.

Like an array, a fixnum array is indexable using […], assignable via […] and :=, supports membership tests using the in operator, and can be used as sequence. Two fixnum arrays are equal by is_now as long as they have the same length and their elements are pairwise equal by fixnum.(==).

The fixnum.Array.contains method accepts any argument value to find, but it will only succeed for fixnums. The comparsion operation is always fixnum.(==).