the scope of the parent thunk
reference to the Graph node for which this scope is created.
Add the given graph node (by symbol) to this scope.
Find the given node among definitions accessible from this scope.
Find the given node among definitions accessible from this scope. It searches in the chain of nested scopes for the first match. If not found, searches in the global scope.
null if not found at all.
the scope of the parent thunk
Sort graph nodes of this scope topologically using depth-first search along node dependencies (graph edges).
Sort graph nodes of this scope topologically using depth-first search along node dependencies (graph edges). This will give evaluation order of the thunk.
reference to the Graph node for which this scope is created.
Helper object to handle construction of nested thunks. One instance is created for each ThunkDef under construction. This corresponds to syntactic nesting of thunks.