Struct Fix 

pub struct Fix<F: HKT>(/* private fields */);

The fixed point of a functor F.

Fix<F> ties the recursive knot: Fix<F> ≅ F<Fix<F>>. It is the core type for recursion schemes — catamorphisms fold a Fix<F> down, anamorphisms build one up.

Uses Rc for indirection, which makes cloning cheap (reference count bump). This is essential for paramorphism, which needs to both preserve and consume each subterm.

Implementations

impl<F: HKT> Fix<F>

pub fn new(f: F::Of<Fix<F>>) -> Self

Wrap one layer of F<Fix<F>> into Fix<F>.

pub fn unfix(self) -> F::Of<Fix<F>>

where F::Of<Fix<F>>: Clone,

Unwrap one layer, consuming the Fix.

If this is the sole owner, the inner value is moved out. Otherwise a shallow clone is made (each child Fix inside is Rc-cloned, which is O(1)).

pub fn unfix_ref(&self) -> &F::Of<Fix<F>>

Borrow one layer without consuming.

Trait Implementations

impl<F: HKT> Clone for Fix<F>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.