DoxigAlpha
std › math › big › int › Managed › normalize

normalize

Normalize a possible sequence of leading zeros.

[1, 2, 3, 4, 0] -> [1, 2, 3, 4] [1, 2, 0, 0, 0] -> [1, 2] [0, 0, 0, 0, 0] -> [0]

Function parameters

Parameters

#
r:*Managed
length:usize

Used to indicate either limit of a 2s-complement integer.

Types

#
TwosCompIntLimit
Used to indicate either limit of a 2s-complement integer.
Mutable
A arbitrary-precision big integer, with a fixed set of mutable limbs.
Const
A arbitrary-precision big integer, with a fixed set of immutable limbs.
Managed
An arbitrary-precision big integer along with an allocator which manages the memory.

Returns the number of limbs needed to store `scalar`, which must be a

Functions

#
calcLimbLen
Returns the number of limbs needed to store `scalar`, which must be a
calcSetStringLimbCount
Assumes `string_len` doesn't account for minus signs if the number is negative.
calcNonZeroTwosCompLimbCount
Compute the number of limbs required to store a 2s-complement number of `bit_count` bits.
calcTwosCompLimbCount
Compute the number of limbs required to store a 2s-complement number of `bit_count` bits.
addMulLimbWithCarry
a + b * c + *carry, sets carry to the overflow bits
llcmp
Returns -1, 0, 1 if |a| < |b|, |a| == |b| or |a| > |b| respectively for limbs.

Source

Implementation

#
pub fn normalize(r: *Managed, length: usize) void {
    assert(length > 0);
    assert(length <= r.limbs.len);

    var j = length;
    while (j > 0) : (j -= 1) {
        if (r.limbs[j - 1] != 0) {
            break;
        }
    }

    // Handle zero
    r.setLen(if (j != 0) j else 1);
}