Crate tinystr

tinystr is a utility crate of the ICU4X project.

It includes TinyAsciiStr, a core API for representing small ASCII-only bounded length strings.

It is optimized for operations on strings of size 8 or smaller. When use cases involve comparison and conversion of strings for lowercase/uppercase/titlecase, or checking numeric/alphabetic/alphanumeric, TinyAsciiStr is the edge performance library.

Examples

use tinystr::TinyAsciiStr;

let s1: TinyAsciiStr<4> = "tEsT".parse().expect("Failed to parse.");

assert_eq!(s1, "tEsT");
assert_eq!(s1.to_ascii_uppercase(), "TEST");
assert_eq!(s1.to_ascii_lowercase(), "test");
assert_eq!(s1.to_ascii_titlecase(), "Test");
assert!(s1.is_ascii_alphanumeric());
assert!(!s1.is_ascii_numeric());

let s2 = TinyAsciiStr::<8>::try_from_raw(*b"New York")
    .expect("Failed to parse.");

assert_eq!(s2, "New York");
assert_eq!(s2.to_ascii_uppercase(), "NEW YORK");
assert_eq!(s2.to_ascii_lowercase(), "new york");
assert_eq!(s2.to_ascii_titlecase(), "New york");
assert!(!s2.is_ascii_alphanumeric());

Details

When strings are of size 8 or smaller, the struct transforms the strings as u32/u64 and uses bitmasking to provide basic string manipulation operations:

• is_ascii_numeric
• is_ascii_alphabetic
• is_ascii_alphanumeric
• to_ascii_lowercase
• to_ascii_uppercase
• to_ascii_titlecase
• PartialEq

TinyAsciiStr will fall back to u8 character manipulation for strings of length greater than 8.

Macros

• tinystr

Structs

• TinyAsciiStr
• UnvalidatedTinyAsciiStr
  A fixed-length bytes array that is expected to be an ASCII string but does not enforce that invariant.

Enums

• TinyStrError

Type Aliases

• TinyStr4
  These are temporary compatability reexports that will be removed in a future version.
• TinyStr8
  These are temporary compatability reexports that will be removed in a future version.
• TinyStr16
  These are temporary compatability reexports that will be removed in a future version.