The Properties Window

The Properties pane is attached to all of the modules - Document Modules, Blackboard Modules, Object Modules and Unit Test Modules. The Properties pane displays information about the currently highlighted expression.

The information in the Properties display includes:
  • The name of the highlighted expression
  • The type of the highlighted expression

    In many cases, the type is just an expression, like Real or Set[Integer]. In some cases, terms in an expression can have more than one valid type. For example, in the expression

    x + y

    all of the instance types of AddType are valid for both x and y. In cases like this, the type of the highlighted expression will be shown as an expression like:

    .TypeN = { Integer, Real, … }

    with "N" in .TypeN replaced by an integer. If the type of an expression is a map, you might see something like:

    .Type1 → .Type2

    .Type1 = { Integer, Real }

    .Type2 = { Bool, Object }

  • A type error message in the case where the highlighted expression contains a type error

    Typically the error message will show the type that the term is expected to have. The expected type is displayed using the same presentation just described if there is more than one possible type for the expected type for the term.

  • The name and type definition from the object definition for the highlighted expression (if there is a definition).