Expand description
§Rustifact extras
In future, this crate may provide other extensions to Rustifact, but for now, it serves to provide jagged array support.
§Motivation
Definition: A jagged array is an array with rows of uneven lengths.
Suppose we have a collections of arrays [T; N1], [T; N2]…, [T; Nn] that we wish
to precalculate at compile time. We can store the elements in a Vec<Vec<T>>, or a [Vec<T>; n],
but these are unsuitable for static memory.
The types JaggedArray and BareJaggedArray allow us to efficiently store jagged arrays in static memory
by pre-populating them in a buildscript with Rustifact.
§Types
JaggedArrayprovides indexing capability at compile time and runtime. Use this type if you’re unsure of your requirements.BareJaggedArrayprovides indexing capability at compile time. Indexes are injected into runtime as token streams.
§A simple example
build.rs
use rustifact::ToTokenStream;
use rustifact_extra::JaggedArrayBuilder;
fn main() {
let mut num_array = JaggedArrayBuilder::new();
num_array.push(vec![1, 2, 3]);
num_array.push(vec![4]);
num_array.push(vec![5, 6]);
rustifact::write_const!(NUM_ARRAY_LEN, usize, num_array.len());
rustifact::write_const!(NUM_ARRAY_ELEMS_LEN, usize, num_array.elems_len());
rustifact::write_static!(NUM_ARRAY, JaggedArray<i32, NUM_ARRAY_LEN, NUM_ARRAY_ELEMS_LEN>, &num_array);
}src/main.rs
rustifact::use_symbols!(NUM_ARRAY, NUM_ARRAY_LEN, NUM_ARRAY_ELEMS_LEN);
use rustifact_extra::JaggedArray;
fn main() {
assert_eq!(NUM_ARRAY[0], [1, 2, 3]);
assert_eq!(NUM_ARRAY[1], [4]);
assert_eq!(NUM_ARRAY[2], [5, 6]);
}Cargo.toml
[package]
# ...
[build-dependencies]
rustifact = "0.9"
rustifact_extra = "0.1"
[dependencies]
rustifact = "0.9"
rustifact_extra = "0.1"