Crate pathmod 

Pathmod — tiny, composable accessors for ergonomic, type-safe deep mutation.

This is the user-facing re-export crate. Depend on pathmod and bring the prelude into scope to use both the derive macros and the runtime:

use pathmod::prelude::*;

#[derive(Accessor, Debug, PartialEq)]
struct Bar { x: i32 }

#[derive(Accessor, Debug, PartialEq)]
struct Foo { a: i32, b: Bar }

let mut foo = Foo { a: 1, b: Bar { x: 2 } };
// Access direct field
let acc_a = Foo::acc_a();
assert_eq!(*acc_a.get(&foo), 1);
acc_a.set(&mut foo, 10);
assert_eq!(foo.a, 10);

// Compose to reach nested leaf Foo -> Bar -> x
let acc_bx = Foo::acc_b().compose(Bar::acc_x());
acc_bx.set_mut(&mut foo, |v| *v += 5);
assert_eq!(foo.b.x, 7);

See also:

• pathmod_core for the Accessor runtime and its operations.
• pathmod_derive for the derive macros generating acc_* and with_*.

Modules

prelude

Prelude re-exporting the most commonly used items.

Structs

Accessor

A small, copyable accessor that focuses into a field F inside a root T.

Traits

Indexing

Indexing operations for accessors that focus Vec<E>.

Derive Macros

Accessor

Derive field accessors for a struct (named or tuple).

EnumAccess

Derive helpers for enum variants (MVP: tuple variants with exactly one field).