# Jetscii
A tiny library to efficiently search strings for ASCII characters.
[](https://travis-ci.org/shepmaster/jetscii) [](https://crates.io/crates/jetskii)
[Documentation](https://shepmaster.github.io/jetscii/)
## Example
```rust
use jetscii::AsciiChars;
let mut search = AsciiChars::new();
search.push(b'-');
search.push(b':');
let part_number = "86-J52:rev1";
let parts: Vec<_> = part_number.split(search).collect();
assert_eq!(&parts, &["86", "J52", "rev1"]);
```
## What's so special about this library?
We use a particular x86-64 SSE 4.2 instruction (`PCMPESTRI`) to gain
great speedups. This method stays fast even when searching for one
character in a set of up to 8 choices.
When `PCMPESTRI` is not available, we fall back to a
universally-supported byte iterator method.
## Benchmarks
### Single character
Searching a 5MiB string of `a`s with a single space at the end:
| **`str.find(AsciiChars)`** | 6501 MB/s |
| `str.as_bytes().iter().position(|&v| v == b' ')` | 1620 MB/s |
| `str.find(|c| c == ' ')` | 1090 MB/s |
| `str.find(' ')` | 1085 MB/s |
| `str.find(&[' '][..])` | 602 MB/s |
| `str.find(" ")` | 293 MB/s |
### Set of characters
Searching a 5MiB string of `a`s with a single ampersand at the end:
| **`str.find(AsciiChars)`** | 6480 MB/s |
| `str.as_bytes().iter().position(|&v| ...)` | 1620 MB/s |
| `str.find(|c| ...)` | 1022 MB/s |
| `str.find(&['<', '>', '&'][..])` | 361 MB/s |
## Contributing
1. Fork it ( https://github.com/shepmaster/jetscii/fork )
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Add a failing test.
4. Add code to pass the test.
5. Commit your changes (`git commit -am 'Add some feature'`)
6. Ensure tests pass.
7. Push to the branch (`git push origin my-new-feature`)
8. Create a new Pull Request