Titlebook: Data Structures of Pascal, Algol 68, PL/1 and Ada; Johan Lewi,Jan Paredaens Book 1986 Springer-Verlag Berlin Heidelberg 1986 Ada.Algol.Alg

PLAYS

Dealing

Marcello Tadini,Giuseppe BorrusoIn strongly typed languages (such as Pascal, Algol 68, PL/1 and Ada) each expression is given a number of properties, defining a set of values and the operations applicable to them. The collection of properties that define such a set of values is called a ..

发现

Values,One of the three basic sets of objects covered by SMALL is the set of ., denoted by V. Values are ., also called . objects, and are processed by the actions specified in a program. The properties of values uniquely determine the kinds of actions that can be performed on them.

Blatant

Gudgeon

Atomic Locations,The . are those values on which only the . CONT is defined. Hence neither the . SEL, nor the . RES is defined on atomic locations.

GREEN

PLE

漂亮

delta-waves

Contents Function,The contents function is only defined on locations (L). It specifies for each location the value it contains. In SMALL, the contents of an atomic location can be any value except a composite datum, whereas the contents of a composite location can only be a composite datum. The motivation for these restrictions is explained in the present chapter.

anarchist

Expressions,Values are internal (abstract) objects for which we need notations called expressions. The set of expressions (E) is the set of all syntactically correct program constructions which may denote values. E is partitioned into two classes: the set of . (N) and the set of . (CE) (see Figure 8.1).