icu_codepointtrie_builder
icu_codepointtrie_builder
is a utility crate of the ICU4X
project.
This crate exposes functionality to build a CodePointTrie
from values provided at runtime.
Because it is normally expected for CodePointTrie data to be pre-compiled, this crate is not
optimized for speed; it should be used during a build phase.
Under the hood, this crate uses the CodePointTrie builder code from ICU4C, UMutableCPTrie
.
For more context, see https://github.com/unicode-org/icu4x/issues/1837.
Build configuration
This crate has two primary modes it can be used in: "wasm"
and "icu4c"
, exposed as
Cargo features. If both are enabled, the code will internally use the wasm codepath.
The "wasm"
mode uses a Wasm module packaged into this Rust crate that contains
pre-compiled ICU4C CodePointTrie builder code. It evaluates the Wasm module using
the Wasmer runtime, which "just works", but it requires a large number of
Rust/Cargo dependencies.
The "icu4c"
mode reduces the number of Rust dependencies, but it requires having a local copy
of ICU4C available. To configure "icu4c"
mode in Cargo, set the following environment variables:
- Set
ICU4C_LIB_PATH
to a directory full of ICU4C static or shared libraries. - Set
ICU4C_LINK_STATICALLY
to any value to use the static libraries. - Set
ICU4C_RENAME_VERSION
to the integer ICU4C version if ICU4C has renaming enabled. By default, we attempt to link non-renamed symbols.
If using dynamic linking, at runtime, you may need to set [DY]LD_LIBRARY_PATH
to the ICU4C_LIB_PATH
.
If not using Cargo, make sure to pass ICU4C_LIB_PATH
to the linker via -L
, link against
icuuc
, icui18n
and icudata
via -l
flags, and set --cfg icu4c_enable_renaming
if you need
renamed ICU4C symbols.
Examples
use CodePointTrie;
use TrieType;
use CodePointTrieBuilder;
use CodePointTrieBuilderData;
let default_value = 1;
let error_value = 2;
let values_by_code_point = &;
let cpt: = CodePointTrieBuilder
.build;
assert_eq!;
assert_eq!;
assert_eq!;
assert_eq!;
assert_eq!; // default value
assert_eq!; // error value
More Information
For more information on development, authorship, contributing etc. please visit ICU4X home page
.