fix -package:incipit-base -is:module -package:ghc

fix f is the least fixed point of the function f, i.e. the least defined x such that f x = x. For example, we can write the factorial function using direct recursion as

>>> let fac n = if n <= 1 then 1 else n * fac (n-1) in fac 5
120

This uses the fact that Haskell’s let introduces recursive bindings. We can rewrite this definition using fix,

>>> fix (\rec n -> if n <= 1 then 1 else n * rec (n-1)) 5
120

Instead of making a recursive call, we introduce a dummy parameter rec; when used within fix, this parameter then refers to fix’s argument, hence the recursion is reintroduced.

Like contrast, but one function is given, and applied to events with matching controls.

In fix $ go a -> do ...; go xy any action after a go is ignored.

Greatest fixpoint of a Bifunctor (a Functor over the first argument with zipping).

A fix-point type.

Fix f is a fix point of the Functor f. Note that in Haskell the least and greatest fixed points coincide, so we don't need to distinguish between Mu f and Nu f. This type used to be called Y, hence the naming convention for all the yfoo functions. This type lets us invoke category theory to get recursive types and operations over them without the type checker complaining about infinite types. The Show instance doesn't print the constructors, for legibility.

Fixed point newtype. Ideally we should use the data-fix package, but right now we're rolling our own due to an initial idea to avoid dependencies to be easier to upstream into GHC (for improvements to the pattern match checker involving equality graphs). I no longer think we can do that without vendoring in some part of just e-graphs, but until I revert the decision we use this type.

A fix-point type.

Allow the result of an ST computation to be used (lazily) inside the computation. Note that if f is strict, fixST f = _|_.

Allow the result of an ST computation to be used (lazily) inside the computation. Note that if f is strict, fixST f = _|_.

The implementation of mfix for IO. If the function passed to fixIO inspects its argument, the resulting action will throw FixIOException.

list of fixities to be aware of

X position of child widget. Default value: 0

Y position of child widget. Default value: 0

Gets whether the Fixed has its own DrawWindow. See fixedSetHasWindow. Removed in Gtk3. Use the Widget version.

'hasWindow' property. See fixedGetHasWindow and fixedSetHasWindow Removed in Gtk3. Use the Widget version.

Moves a child of a Fixed container to the given position.