type

SpecSlots

@Js const mixin SpecSlots

SpecSlots is a map of named Specs

each	Iterate through the children
eachWhile	Iterate through the children until function returns non-null
get	Get the child slot spec
has	Return if the given slot name is defined.
isEmpty	Return if slots are empty
missing	Return if the given slot name is undefined.
names	Convenience to list the slots names; prefer `each`.

abstract Void each(|Spec| f)

Iterate through the children

abstract Obj? eachWhile(|Spec->Obj?| f)

Iterate through the children until function returns non-null

abstract Spec? get(Str name, Bool checked := true)

Get the child slot spec

abstract Bool has(Str name)

Return if the given slot name is defined.

abstract Bool isEmpty()

Return if slots are empty

abstract Bool missing(Str name)

Return if the given slot name is undefined.

abstract Str[] names()

Convenience to list the slots names; prefer each.