Package gavo :: Package base :: Module complexattrs

Module complexattrs

Attributes with structure (i.e., containing structures or more than one atom).

These come with parsers of their own, in some way or other.

Structure attributes, which do not have string literals and have some sort of internal structure, add methods

create(instance, ctx, name) -> structure -- creates a new object suitable

as attribute value and returns it (for stuctures, instance becomes the parent of the new structure as a side effect of this operation). This is what should later be fed to feedObject. It must work as a parser, i.e., have a feedEvent method. The name argument gives the name of the element that caused the create call, allowing for polymorphic attrs.

replace(instance, oldVal, newVal) -> None -- replaces oldVal with newVal; this

works like feedObject, except that an old value is overwritten.

iterEvents(instance) -> events -- yields events to recreate its value

on another instance.

Classes
	ListOfAtomsAttribute is an attribute definition for an item containing many elements of the same type.
	SetOfAtomsAttribute is an attribute definition for an item containing many elements of the same type, when order doesn't matter but lookup times do.
	DictAttribute an attribute containing a mapping.
	PropertyAttribute adds the property protocol to the parent instance.
	StructAttribute describes an attribute containing a Structure
	MultiStructAttribute describes an attribute containing one of a class of Structures.
	StructListAttribute describes an attribute containing a homogeneous list of structures.
	UniquedStructListAttribute A StructListAttribute that will only admit one child per value of uniqueAttribute, overwriting existing entries if existing.
	MultiStructListAttribute describes a list of polymorphous children.