Specification

Store

Interface Specification

Constructors

• newref: ExpVal → Ref

Observers

• deref: Ref → ExpVal
• setref!: Ref x ExpVal → Unspecified

Values

• ExpVal = Int + Bool + Proc + Ref(ExpVal)
• DenVal = ExpVal

Interface

Constructors

• num-val: Int → ExpVal
• bool-val: Bool → ExpVal
• proc-val: Proc → ExpVal
• ref-val: Ref → ExpVal

Extractors

• expval→num: ExpVal → Int

Implementation