icu_pattern 
icu_pattern is a utility crate of the ICU4X project.
It includes a [Pattern] type which supports patterns with various storage backends.
The types are tightly coupled with the [writeable] crate.
Examples
Parsing and interpolating with a single-placeholder pattern:
use SinglePlaceholderPattern;
use assert_writeable_eq;
// Parse a pattern string:
let pattern = try_from_str
.unwrap;
// Interpolate into the pattern string:
assert_writeable_eq!;
More Information
For more information on development, authorship, contributing etc. please visit ICU4X home page.