tweak
Tweak provides when/then clauses to your context in described state.
Installation
Add the following to your Cargo.toml:
toml
[dependencies]
tweak = "*"
Examples
Simple context manipulation.
```rust
extern crate tweak;
use tweak::Case;
struct XY {
x: i32,
y: i32,
}
impl XY {
fn new(x: i32, y: i32) -> Self {
Self { x, y }
}
}
let mut xy = XY::new(5, 0);
let res = Case::::new("coords")
.when("x > 0", |ctx| Ok(ctx.x > 0))
.thencase("tweak x", |case| {
case.when("x == 5", |ctx| Ok(ctx.x == 5))
.then("multiply x by 3", |ctx| {
ctx.x *= 3;
Ok(())
})
.when("when x > 10", |ctx| Ok(ctx.x > 10))
.then("set x to 10", |ctx| {
ctx.x = 10;
Ok(())
})
})
.when("y > 0", |ctx| Ok(ctx.y > 0))
.thencase("tweak y", |case| {
case.when("y > 0", |ctx| Ok(ctx.y > 0))
.then("divide 10 by y", |ctx| {
ctx.y = 10 / ctx.y;
Ok(())
})
})
.run(&mut xy);
asserteq!(Ok(true), res);
asserteq!(xy.x, 10);
assert_eq!(xy.y, 0);
```
License: MIT