[](https://crates.io/crates/pluck)
[](https://docs.rs/pluck)
# pluck
`pluck!` is a macro that creates a lambda that plucks the provided
property from the argument. Great with iterators.
## Access
`pluck!` provides many different ways to access values.
### Tuple Indices
Provide the index to extract.
```rust
let list = [(0, "a"), (1, "b"), (2, "c")];
let first = list.iter().map(pluck!(.0)).collect::<Vec<_>>();
assert_eq!(first, &[0, 1, 2]);
let second = list.iter().map(pluck!(.1)).collect::<Vec<_>>();
assert_eq!(second, &["a", "b", "c"]);
```
### Struct Properties
Provide the property name to extract.
```rust
struct Person { name: &'static str }
let list = [Person { name: "Alice" }];
let names = list.iter().map(pluck!(.name)).collect::<Vec<_>>();
assert_eq!(names, &["Alice"]);
```
### By Reference
Precede the property name with `&` to pluck by reference.
```rust
let list = [(0, "a"), (1, "b"), (2, "c")];
let first = list.iter().map(pluck!(&.0)).collect::<Vec<_>>();
assert_eq!(first, &[&0, &1, &2]);
```
### Mutable Reference
Precede the property name with `&mut` to pluck by mutable reference.
```rust
let mut list = [(0, "a"), (1, "b"), (2, "c")];
for num in list.iter_mut().map(pluck!(&mut .0)) {
*num += 1;
}
assert_eq!(list, [(1, "a"), (2, "b"), (3, "c")]);
```
### Index Type
`pluck!` works with types implementing [`Index`](std::ops::Index) and
[`IndexMut`](std::ops::IndexMut).
```rust
let list = [[0], [1], [2]];
let first = list.iter().map(pluck!([0])).collect::<Vec<_>>();
assert_eq!(first, &[0, 1, 2]);
let first_ref = list.iter().map(pluck!(&[0])).collect::<Vec<_>>();
assert_eq!(first_ref, &[&0, &1, &2]);
```
### Deref
`pluck!` works with types implementing [`Deref`](std::ops::Deref) and
[`DerefMut`](std::ops::DerefMut).
```rust
let list = vec![&0, &1, &2];
let derefed = list.into_iter().map(pluck!(*)).collect::<Vec<_>>();
assert_eq!(derefed, &[0, 1, 2]);
let list = vec![&&&0, &&&1, &&&2];
let derefed = list.into_iter().map(pluck!(***)).collect::<Vec<_>>();
assert_eq!(derefed, &[0, 1, 2]);
```
## Combinations
`pluck!` is designed to allow you to arbitrarily combine accessing. You
can specify precedence with `()`.
```rust
struct Person { name: &'static str }
let mut list = vec![[&Person { name: "Alice" }]];
let derefed = list.iter_mut().map(pluck!((*[0]).name)).collect::<Vec<_>>();
assert_eq!(derefed, &["Alice"]);
```
# License: MIT