How do WF4 parse the Expressions?

How do WF4 parse expressions and return the values.

for example the If activity has the Condition attribute that we can write expression like [ true = true ] or [ "str" = "str" ] or guids... what is the class responsible for this parsing?

I noticed that when we put the [] so开发者_高级运维 the engine will directly parse the content of the brackets, in other world what is the class that parses the VB expression in WF4.

The class you are looking for is VisualBasicValue< TResult>.