Package org.aavso.tools.vstar.vela

Class VeLaEnvironment<T>

java.lang.Object

org.aavso.tools.vstar.vela.VeLaEnvironment<T>

Direct Known Subclasses:

EmptyVeLaEnvironment, VeLaScope, VeLaValidObservationEnvironment

public class VeLaEnvironment<T>
extends Object

A generic symbol binding and lookup environment implementation, the base class for all VeLa environments.

Field Summary

Fields

Modifier and Type	Field	Description
protected Map<String,T>	cache
protected Set<String>	constants

Constructor Summary

Constructors

Constructor	Description
VeLaEnvironment()	Construct an environment with an empty name and constant set.
VeLaEnvironment(Map<String,T> map, Set<String> isBoundConstants)	Construct an environment with a specified empty name and constant set.

Method Summary

Modifier and Type	Method	Description
void	addAll(VeLaEnvironment<T> other)	Add all symbol bindings from another scope to this one.
void	bind(String name, T value, boolean isConstant)	Bind a value to a name. It is an invariant that a constant binding cannot be overridden.
boolean	hasBinding(String name)	Deprecated.
boolean	isEmpty()	Is this VeLa environment empty?
boolean	isMutable()	Is this environment mutable (can be modified)?
Optional<T>	lookup(String name)	Lookup the named symbol in the environment.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

cache

protected Map<String,T> cache

constants

protected Set<String> constants

Constructor Details

VeLaEnvironment

public VeLaEnvironment()

Construct an environment with an empty name and constant set.

VeLaEnvironment

public VeLaEnvironment(Map<String,T> map,
 Set<String> isBoundConstants)

Construct an environment with a specified empty name and constant set.

Method Details

isMutable

public boolean isMutable()

Is this environment mutable (can be modified)?

Returns:

true if mutable, false if not

lookup

public Optional<T> lookup(String name)

Lookup the named symbol in the environment.

Parameters:

name - The symbol's name.

Returns:

An optional Operand instance if it exists.

hasBinding

@Deprecated
public boolean hasBinding(String name)

Deprecated.

Does this environment contain the named binding?

Parameters:

name - The name of the binding to lookup.

Returns:

Whether the name is bound in this environment. Less useful now, given the use of Optional values

bind

public void bind(String name,
 T value,
 boolean isConstant)

Bind a value to a name.
It is an invariant that a constant binding cannot be overridden.

Parameters:

name - The name to which to bind the value.

value - The value to be bound.

isConstant - Is this a constant binding?

addAll

public void addAll(VeLaEnvironment<T> other)

Add all symbol bindings from another scope to this one.

Parameters:

other - The scope to be added to this one.

isEmpty

public boolean isEmpty()

Is this VeLa environment empty?

toString

public String toString()

Overrides:

toString in class Object