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EiffelStudio

# New expression dialog

Adding new expressions to the list of expressions that should be dynamically evaluated is performed via a dialog.

context: Current feature | context: As object

The first part in the dialog makes it possible to select the context of the expression.

- The default context is the context of the currently selected call stack element. This context gives access to the locals, the arguments, the result and the enclosing object features.
- The object context, that requires a valid object address, gives access to the features of the selected object. But if the "As object" is selected, the result of the expression, is the pointed object it self; and you can name the object (see the second screenshot).
- The last context, the class-related context, gives access to the once and constants features of that class. It requires a valid class name.

The second part prompts for the expression itself. This field supports arguments, dot calls and operators (to a certain extent), but does not support creation expressions, agents or static calls (as in "feature {MY_CLASS}.my_feature"). Genericity is partially supported. Despite these limitations, we believe the expression evaluation tool should provide you with a lot of useful functionality.