Module Primus.Env

The evaluation environment.

The environment binds variables to values and value generators.

A variable is bound if it was either bound to a value with set or to a value generator with add. A variable is unset if it is bound but not bound to a value.

A variable is undefined if it is not bound. Accessing an undefined variable raises the Undefined_var exception. Accessing an unset variable triggers the generated observation and the variable becomes bound to the generated value.