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This is an example of documentation generated by ZigDoc, an alternative to Zig's built-in Auto Doc feature. See also examples in other modes/formats. The project being documented here (as the example) is the Zig standard library. Private Type Function

SliceIterRandomOrder

Private Type Function
std.treap.SliceIterRandomOrder
fn SliceIterRandomOrder(comptime T: type) type

For iterating a slice in a random order https://lemire.me/blog/2017/09/18/visiting-all-values-in-an-array-exactly-once-in-random-order/

Fields

rng: std.Random
slice: []T
index: usize = undefined
offset: usize = undefined
co_prime: usize

Types

Functions

pub fn init(slice: []T, rng: std.Random) Self
pub fn reset(self: *Self) void
pub fn next(self: *Self) ?*T

File

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fn SliceIterRandomOrder(comptime T: type) type {
    return struct {
        rng: std.Random,
        slice: []T,
        index: usize = undefined,
        offset: usize = undefined,
        co_prime: usize,

        const Self = @This();

        pub fn init(slice: []T, rng: std.Random) Self {
            return Self{
                .rng = rng,
                .slice = slice,
                .co_prime = blk: {
                    if (slice.len == 0) break :blk 0;
                    var prime = slice.len / 2;
                    while (prime < slice.len) : (prime += 1) {
                        var gcd = [_]usize{ prime, slice.len };
                        while (gcd[1] != 0) {
                            const temp = gcd;
                            gcd = [_]usize{ temp[1], temp[0] % temp[1] };
                        }
                        if (gcd[0] == 1) break;
                    }
                    break :blk prime;
                },
            };
        }

        pub fn reset(self: *Self) void {
            self.index = 0;
            self.offset = self.rng.int(usize);
        }

        pub fn next(self: *Self) ?*T {
            if (self.index >= self.slice.len) return null;
            defer self.index += 1;
            return &self.slice[((self.index *% self.co_prime) +% self.offset) % self.slice.len];
        }
    };
}