22 lines
702 B
Rust
22 lines
702 B
Rust
//! We don't use `rand`, as that's too many things for us.
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//!
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//! We currently use oorandom instead, but it's missing these two utilities.
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//! Perhaps we should switch to `fastrand`, or our own small PRNG, it's not like
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//! we need anything more complicated than xor-shift.
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pub fn shuffle<T>(slice: &mut [T], mut rand_index: impl FnMut(usize) -> usize) {
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let mut remaining = slice.len() - 1;
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while remaining > 0 {
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let index = rand_index(remaining);
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slice.swap(remaining, index);
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remaining -= 1;
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}
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}
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pub fn seed() -> u64 {
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use std::collections::hash_map::RandomState;
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use std::hash::{BuildHasher, Hasher};
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RandomState::new().build_hasher().finish()
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}
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