Naming

Mapping

There are several techniques to map names to values, often combined for a single name resolution.

The main idea is resolve(name, context), that maps a name in a context to exactly one value.

• table-based lookup: correspondence of name-value in a table
• recursive lookup: resolution provides a new name rather than a mapping, new name looked up
• multiple lookup: search multiple contexts to find the name

So why names?

Computer systems use names to identify components

• addresses of values in objects
• addresses of other systems

Components may be passed by value or reference

• value: copy component

  • only makes sense for some usage
  • better for modularity: minimizes side effects

• reference: provide the name of the component

Names facilitate sharing

• different components can reference the same object
• name is used to provide a reference to each component

Names allow deferred lookup

• to which object does a name refer?
• decision can be make when the name is looked up

Indirection: using intermediary to associate name and object

Binding: association of a name to a particular object

Contexts and Operations

• context: information that helps determine name

  • e.g. identity of the user
  • location making the request
  • current working directory