DoxigAlpha

init

Function parameters

Parameters

#
pointer:anytype
fillFn:fn (ptr: @TypeOf(pointer), buf: []u8) void

Fast unbiased random numbers.

Types

#
DefaultPrng
Fast unbiased random numbers.
DefaultCsprng
Cryptographically secure random numbers.

Functions in this namespace

Functions

#
bytes
Read random bytes into the specified buffer until full.
enumValue
Returns a random value from an enum, evenly distributed.
enumValueWithIndex
Returns a random value from an enum, evenly distributed.
int
Returns a random int `i` such that `minInt(T) <= i <= maxInt(T)`.
uintLessThanBiased
Constant-time implementation off `uintLessThan`.
uintLessThan
Returns an evenly distributed random unsigned integer `0 <= i < less_than`.
uintAtMostBiased
Constant-time implementation off `uintAtMost`.
uintAtMost
Returns an evenly distributed random unsigned integer `0 <= i <= at_most`.
intRangeLessThanBiased
Constant-time implementation off `intRangeLessThan`.
intRangeLessThan
Returns an evenly distributed random integer `at_least <= i < less_than`.
intRangeAtMostBiased
Constant-time implementation off `intRangeAtMostBiased`.
intRangeAtMost
Returns an evenly distributed random integer `at_least <= i <= at_most`.
float
Return a floating point value evenly distributed in the range [0, 1).
floatNorm
Return a floating point value normally distributed with mean = 0, stddev = 1.
floatExp
Return an exponentially distributed float with a rate parameter of 1.
shuffle
Shuffle a slice into a random order.
shuffleWithIndex
Shuffle a slice into a random order, using an index of a
weightedIndex
Randomly selects an index into `proportions`, where the likelihood of each
limitRangeBiased
Convert a random integer 0 <= random_int <= maxValue(T),

Source

Implementation

#
pub fn init(pointer: anytype, comptime fillFn: fn (ptr: @TypeOf(pointer), buf: []u8) void) Random {
    const Ptr = @TypeOf(pointer);
    assert(@typeInfo(Ptr) == .pointer); // Must be a pointer
    assert(@typeInfo(Ptr).pointer.size == .one); // Must be a single-item pointer
    assert(@typeInfo(@typeInfo(Ptr).pointer.child) == .@"struct"); // Must point to a struct
    const gen = struct {
        fn fill(ptr: *anyopaque, buf: []u8) void {
            const self: Ptr = @ptrCast(@alignCast(ptr));
            fillFn(self, buf);
        }
    };

    return .{
        .ptr = pointer,
        .fillFn = gen.fill,
    };
}