ai.grakn.graql.admin

Interface Unifier

All Known Implementing Classes:

UnifierImpl

public interface Unifier

Interface for resolution unifier defined as a finite set of mappings between variables xi and terms ti: θ = {x1/t1, x2/t2, ..., xi/ti}. Both variables and terms are defined in terms of graql VarNames. For a set of expressions Γ, the unifier θ maps elements from Γ to a single expression φ : Γθ = {φ}.

Author:

Kasper Piskorski

Method Summary

Modifier and Type	Method and Description
VarName	addMapping(VarName key, VarName value) add a new mapping
boolean	containsKey(VarName key)
boolean	containsValue(VarName value)
VarName	get(VarName key)
Set<Map.Entry<VarName,VarName>>	getMappings()
boolean	isEmpty()
Set<VarName>	keySet()
Map<VarName,VarName>	map()
Unifier	merge(Unifier d)
Unifier	removeTrivialMappings()
int	size()
Collection<VarName>	values()

Method Detail

get

VarName get(VarName key)

Parameters:

key - specific variable

Returns:

corresponding term

addMapping

VarName addMapping(VarName key,
                   VarName value)

add a new mapping

Parameters:

key - variable

value - term

Returns:

previous value associated with key, or null if there was no mapping for key

isEmpty

boolean isEmpty()

Returns:

true if the set of mappings is empty

map

Map<VarName,VarName> map()

keySet

Set<VarName> keySet()

Returns:

variables present in this unifier

values

Collection<VarName> values()

Returns:

terms present in this unifier

getMappings

Set<Map.Entry<VarName,VarName>> getMappings()

Returns:

set of mappings constituting this unifier

containsKey

boolean containsKey(VarName key)

Parameters:

key - variable to be inspected for presence

Returns:

true if specified key is part of a mapping

containsValue

boolean containsValue(VarName value)

Parameters:

value - term to be checked for presence

Returns:

true if specified value is part of a mapping

merge

Unifier merge(Unifier d)

Parameters:

d - unifier to be merged with this unifier

Returns:

merged unifier

removeTrivialMappings

Unifier removeTrivialMappings()

size

int size()

Returns:

number of mappings that consittute this unifier