container

Module nu.forms.collections.abc.container.

Container capability.

ContainerForm: values that support containment checks.

Follows Python's collections.abc.Container pattern.

Name	Call	Meaning
ContainerForm	`ContainerForm()`	Base for values that support containment checks, like collections.abc.Container.

ContainerForm

Base for values that support containment checks, like collections.abc.Container.

ContainerForm()

Path nu.forms.collections.abc.ContainerForm.

Notes

Python's in operator coerces __contains__'s result to bool at the C level, which would collapse the Nu tree to a constant True. .contains(item) returns a real Bool tree node instead.

Example

nu.run(nu.Set({1, 2, 3}).contains(2))[0]

True

Methods

Whether item is a member of self.

Builds Bool.

Arguments

Name	Type	Default	Meaning
`item`	`object`		the value to test for membership.

Yields

True when item is in self, False otherwise. EMPTY when self or item is EMPTY.

Examples

nu.run(nu.Set({1, 2, 3}).contains(2))[0]

True

nu.run(nu.Set({1, 2, 3}).contains(9))[0]

False

Inherited methods

From nu.lang.forms.Form:

Call	Builds	Meaning
`a == b`	`Bool`	Self equal to other by value: an `Eq` term, never a Python bool.
`a != b`	`Bool`	Self not equal to other by value: a `Ne` term, never a Python bool.
`.is_empty()`	`Bool`	True if this Form yields the EMPTY sentinel.
`.not_empty()`	`Bool`	True if this Form does not yield EMPTY.
`.fallback(*alternatives)`	`Self`	The first of this value and `alternatives` that is not EMPTY.

From builtins.object: