com.oracle.truffle.api.metadata

Interface ScopeProvider<C>

public interface ScopeProvider<C>

Provider of guest language scope information.

Register the scope provider service for a guest language by directly implementing the TruffleLanguage with this interface.

Since:

0.26

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	ScopeProvider.AbstractScope Abstraction of a scope in a guest language program.

Method Summary

Modifier and Type	Method and Description
ScopeProvider.AbstractScope	findScope(C langContext, Node node, Frame frame) Find a hierarchy of scopes enclosing the given node.

Method Detail

findScope

ScopeProvider.AbstractScope findScope(C langContext,
                                      Node node,
                                      Frame frame)

Find a hierarchy of scopes enclosing the given node. There must be at least one scope provided, that corresponds to the enclosing function. The language might provide additional block scopes, closure scopes, etc. The scope hierarchy should correspond with the scope nesting, from the inner-most to the outer-most. The scopes are expected to contain variables valid at the associated node.

In general, there can be a different list of scopes with different variables and arguments returned for different Frame instances, as scopes may depend on runtime information. Known lexical scopes are returned when frame argument is null.

The Scope.findScopes(com.oracle.truffle.api.instrumentation.TruffleInstrument.Env, com.oracle.truffle.api.nodes.Node, com.oracle.truffle.api.frame.Frame) provides result of this method called on the implementation of the enclosing RootNode . When the guest language does not implement this service, the enclosing RootNode's scope with variables read from its FrameDescriptor's FrameSlots is provided by default.

Parameters:

langContext - the language execution context

node - a node to find the enclosing scopes for. The node is inside a RootNode associated with this language.

frame - The current frame the node is in, or null for lexical access when the program is not running, or is not suspended at the node's location.

Returns:

an instance of ScopeProvider.AbstractScope.

Since:

0.26