wyal.lang

Interface SyntacticHeap

All Known Implementing Classes:

AbstractSyntacticHeap, StructurallyEquivalentHeap, WyalFile

public interface SyntacticHeap

A syntactic heap represents a collection of syntactic items.

Author:

David J. Pearce

Method Summary

Modifier and Type	Method and Description
<T extends SyntacticItem> T	allocate(T item) Allocate a given syntactic item into this heap.
int	getIndexOf(SyntacticItem item) Determine the index of a given syntactic item in this heap.
SyntacticItem	getSyntacticItem(int ith) Return the ith syntactic item in this heap.
int	size() Get the number of items in the heap.

Method Detail

size

int size()

Get the number of items in the heap.

Returns:

getSyntacticItem

SyntacticItem getSyntacticItem(int ith)

Return the ith syntactic item in this heap. This may return null if the item in question has been garbage collected.

Parameters:

index -

Returns:

getIndexOf

int getIndexOf(SyntacticItem item)

Determine the index of a given syntactic item in this heap.

Parameters:

item -

Returns:

allocate

<T extends SyntacticItem> T allocate(T item)

Allocate a given syntactic item into this heap. The item must not already be allocated to another heap. This will recursively allocate children not already allocated to this heap. Observe that the item returned is the actual object allocated into this heap. One should not assume that the item given is that which is actually allocated.

This method will not permit mixed allocation items. That is, when it encounters an item already allocated to another heap it will simple throw an exception.

Parameters:

item -

Returns: