Context-class: Evaluation Contexts

Description Translation Author(s)

Description

The Context class is for representing contexts in which expressions are evaluated. This might be an R environment, a database, or some other external system.

Translation

Contexts play an important role in translation. When extracting an object by name, the context can delegate to a SymbolFactory to create a Symbol object that is a lazy reference to the object. The reference is expressed in the target language. If there is no SymbolFactory, i.e., it has been set to NULL, then evaluation is eager.

The intent is to decouple the type of the context from a particular language, since a context could support the evaluation of multiple languages. The accessors below effectively allow one to specify the desired target language.

symbolFactory(x), symbolFactory(x) <- value: Get or set the current SymbolFactory (may be NULL).

Author(s)

Michael Lawrence


rsolr documentation built on April 22, 2021, 9:07 a.m.