38 lines
908 B
Markdown
38 lines
908 B
Markdown
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# with-checked-bytes
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A Rust extension trait for `&mut str` to simplify manipulating UTF-8 strings as if they were
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plain ASCII bytes. The result is only applied to the original string if the end result of
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the modification is valid UTF-8.
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## Examples
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```rust
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use with_checked_bytes::WithCheckedBytes;
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let mut my_string = String::from("hello");
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my_string.with_checked_bytes_mut(|s| {
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s[1] += 1;
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}).unwrap();
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assert_eq!(my_string, "hfllo");
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```
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```rust
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let mut my_string = String::from("hello");
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let old_value = my_string.with_checked_bytes_mut(|s| {
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std::mem::replace(&mut s[3], b'z')
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}).unwrap();
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assert_eq!(old_value, b'l');
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assert_eq!(my_string, "helzo");
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```
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```rust
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let mut my_string = String::from("hello");
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my_string.with_checked_bytes_mut(|s| {
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s[1] = 0xff; // not valid UTF-8
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}).unwrap(); // will panic - original string remains unmodified
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```
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## Licence
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Apache 2.0. See `LICENSE`.
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