Class ExpressionState


public class ExpressionState extends Object
ExpressionState is for maintaining per-expression-evaluation state: any changes to it are not seen by other expressions, but it gives a place to hold local variables and for component expressions in a compound expression to communicate state. This is in contrast to the EvaluationContext, which is shared amongst expression evaluations, and any changes to it will be seen by other expressions or any code that chooses to ask questions of the context.

It also acts as a place to define common utility routines that the various AST nodes might need.

Andy Clement, Juergen Hoeller, Sam Brannen