mirror of
https://github.com/urbit/ares.git
synced 2024-11-29 22:56:28 +03:00
92 lines
2.9 KiB
Markdown
92 lines
2.9 KiB
Markdown
|
# This fork
|
||
|
|
|
||
|
|
This modifies ibig to accept a custom allocator for some operations.
|
||
|
|
Specifically, any function which ends in `_stack` will never allocate
|
||
|
|
except by calling the passed-in allocator with trait `Stack`. This
|
||
|
|
allocator is assumed to *not* require deallocation, so we leak
|
||
|
|
everything we allocate in that way.
|
||
|
|
|
||
|
|
Further, we leak *all* allocations of multi-word `UBig`s, even those created by
|
||
|
|
non-`_stack` functions. This means that this repo *must* be used
|
||
|
|
exclusively with `_stack` functions (or others that you know do not
|
||
|
|
allocate). To allow easier integration of future upstream changes, we
|
||
|
|
do not modify existing functions where possible, even though they are no
|
||
|
|
longer safe to use.
|
||
|
|
|
||
|
|
It is recommended to use
|
||
|
|
[assert-no-alloc](https://github.com/Windfisch/rust-assert-no-alloc) to
|
||
|
|
verify that no allocations happen.
|
||
|
|
|
||
|
|
# ibig
|
||
|
|
|
||
|
|
[](https://crates.io/crates/ibig)
|
||
|
|
[](https://docs.rs/ibig)
|
||
|
|
|
||
|
|
[](https://github.com/tczajka/ibig-rs/actions/workflows/tests.yml)
|
||
|
|
|
||
|
|
A big integer library with good performance.
|
||
|
|
|
||
|
|
The library implements efficient large integer arithmetic in pure Rust.
|
||
|
|
|
||
|
|
The two integer types are `UBig` (for unsigned integers) and `IBig` (for signed integers).
|
||
|
|
|
||
|
|
Modular arithmetic is supported by the module `modular`.
|
||
|
|
|
||
|
|
## Examples
|
||
|
|
|
||
|
|
```rust
|
||
|
|
use ibig::{ibig, modular::ModuloRing, ubig, UBig};
|
||
|
|
|
||
|
|
let a = ubig!(12345678);
|
||
|
|
let b = ubig!(0x10ff);
|
||
|
|
let c = ibig!(-azz base 36);
|
||
|
|
let d: UBig = "15033211231241234523452345345787".parse()?;
|
||
|
|
let e = 2 * &b + 1;
|
||
|
|
let f = a * b.pow(10);
|
||
|
|
|
||
|
|
assert_eq!(e, ubig!(0x21ff));
|
||
|
|
assert_eq!(c.to_string(), "-14255");
|
||
|
|
assert_eq!(
|
||
|
|
f.in_radix(16).to_string(),
|
||
|
|
"1589bda8effbfc495d8d73c83d8b27f94954e"
|
||
|
|
);
|
||
|
|
assert_eq!(
|
||
|
|
format!("hello {:#x}", d % ubig!(0xabcd1234134132451345)),
|
||
|
|
"hello 0x1a7e7c487267d2658a93"
|
||
|
|
);
|
||
|
|
|
||
|
|
let ring = ModuloRing::new(&ubig!(10000));
|
||
|
|
let x = ring.from(12345);
|
||
|
|
let y = ring.from(55443);
|
||
|
|
assert_eq!(format!("{}", x - y), "6902 (mod 10000)");
|
||
|
|
```
|
||
|
|
|
||
|
|
## Optional dependencies
|
||
|
|
|
||
|
|
* `std` (default): for `std::error::Error`.
|
||
|
|
* `num-traits` (default): integral traits.
|
||
|
|
* `rand` (default): random number generation.
|
||
|
|
* `serde`: serialization and deserialization.
|
||
|
|
|
||
|
|
## Benchmarks
|
||
|
|
|
||
|
|
[Benchmarks](https://github.com/tczajka/bigint-benchmark-rs) contains a quick benchmark of
|
||
|
|
Rust big integer libraries.
|
||
|
|
|
||
|
|
## License
|
||
|
|
|
||
|
|
Licensed under either of
|
||
|
|
|
||
|
|
* Apache License, Version 2.0
|
||
|
|
([LICENSE-APACHE](LICENSE-APACHE) or https://www.apache.org/licenses/LICENSE-2.0)
|
||
|
|
* MIT license
|
||
|
|
([LICENSE-MIT](LICENSE-MIT) or https://opensource.org/licenses/MIT)
|
||
|
|
|
||
|
|
at your option.
|
||
|
|
|
||
|
|
## Contribution
|
||
|
|
|
||
|
|
Unless you explicitly state otherwise, any contribution intentionally submitted
|
||
|
|
for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
|
||
|
|
dual licensed as above, without any additional terms or conditions.
|