Package net.hydromatic.morel.compile

Class Environment

java.lang.Object

net.hydromatic.morel.compile.Environment

Direct Known Subclasses:

Environments.EmptyEnvironment, Environments.MapEnvironment, Environments.SubEnvironment

public abstract class Environment
extends Object

Environment for validation/compilation.

Every environment is immutable; when you call bind(net.hydromatic.morel.ast.Core.IdPat, java.lang.Object), a new environment is created that inherits from the previous environment. The new environment may obscure bindings in the old environment, but neither the new nor the old will ever change.

To create an empty environment, call Environments.empty().

See Also:

TypeResolver.TypeEnv, EvalEnv

Constructor Summary

Constructors

Constructor	Description
Environment()

Method Summary

Modifier and Type	Method	Description
String	asString()	Converts this environment to a string.
Environment	bind(Core.IdPat id, Object value)	Creates an environment that is the same as a given environment, plus one more variable.
protected Environment	bind(Binding binding)
Environment	bindAll(Iterable<Binding> bindings)	Creates an environment that is the same as this, plus the given bindings.
(package private) abstract int	distance(int soFar, Core.NamedPat id)
void	forEachType(BiConsumer<String,Type> consumer)	Calls a consumer for each variable and its type.
void	forEachValue(BiConsumer<String,Object> consumer)	Calls a consumer for each variable and its value.
abstract @Nullable Binding	getOpt(String name)	Returns the binding of name if bound, null if not.
abstract @Nullable Binding	getOpt(Core.NamedPat id)	Returns the binding of id if bound, null if not.
Map<String,Binding>	getValueMap()	Returns a map of the values and bindings.
(package private) abstract Environment	nearestAncestorNotObscuredBy(Set<Core.NamedPat> names)	If this environment only defines bindings in the given set, returns its parent.
Environment	plus(Environment env)	Returns this environment plus the bindings in the given environment.
(package private) abstract void	visit(Consumer<Binding> consumer)	Visits every variable binding in this environment.

Methods inherited from class java.lang.Object

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

Constructor Detail

Environment

public Environment()

Method Detail

visit

abstract void visit(Consumer<Binding> consumer)

Visits every variable binding in this environment.

Bindings that are obscured by more recent bindings of the same name are visited, but after the more obscuring bindings.

asString

public String asString()

Converts this environment to a string.

This method does not override the Object.toString() method; if we did, debuggers would invoke it automatically, burning lots of CPU and memory.

getOpt

public abstract @Nullable Binding getOpt(String name)

Returns the binding of name if bound, null if not.

getOpt

public abstract @Nullable Binding getOpt(Core.NamedPat id)

Returns the binding of id if bound, null if not.

bind

public Environment bind(Core.IdPat id,
                        Object value)

Creates an environment that is the same as a given environment, plus one more variable.

bind

protected Environment bind(Binding binding)

forEachType

public void forEachType(BiConsumer<String,Type> consumer)

Calls a consumer for each variable and its type. Does not visit obscured bindings.

forEachValue

public void forEachValue(BiConsumer<String,Object> consumer)

Calls a consumer for each variable and its value. Does not visit obscured bindings, or bindings to Unit.INSTANCE.

getValueMap

public final Map<String,Binding> getValueMap()

Returns a map of the values and bindings.

bindAll

public final Environment bindAll(Iterable<Binding> bindings)

Creates an environment that is the same as this, plus the given bindings.

nearestAncestorNotObscuredBy

abstract Environment nearestAncestorNotObscuredBy(Set<Core.NamedPat> names)

If this environment only defines bindings in the given set, returns its parent. Never returns null. The empty environment returns itself.

distance

abstract int distance(int soFar,
                      Core.NamedPat id)

plus

public Environment plus(Environment env)

Returns this environment plus the bindings in the given environment.