Executing methods

Indirectly invoking method deposit through the top-level variable `bal-set' caused the following changes in the diagram to occur:

• the call of method `deposit' was initiated from the top-level via the statement: (bal-set 100).
• a new environment frame was created for the lambda-abstraction `deposit' with the argument of the call stored in it as a key/value$=>$ pair: `amount 100'.
• the new environment frame was linked with the proper environment frame of the parent of `deposit' which is the constructor of the object.
• the arrowed line labelled `$<$env 1$>$' shows that `deposit' has access to the environment frame of its parent.
• the body of method `deposit' is displayed
• the return value of method `deposit'(200) is stored in the variable `balance' in the environment frame of the parent (constructor). The diagram shows the value of `balance' before and after the execution of `deposit' (100:200).

Georg P. Loczewski 2004-03-05

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