An approach to support abstraction facilities is described. In program design, abstraction techniques are very effective. But current familiar languages does not support various kinds of abstraction facilities. In order to add abstraction facilities to existing programming languages, a macro language MACLAM (A Macro Language for Abstraction Mechanisms) has been designed and implemented. MACLAM is a general-purpose and syntax-directed macro language, and attention of this language is focused on data as well as on control. The MACLAM processor is implemented as a complete pre-processor for various kinds of base language processors. MACLAM supports three kinds of abstraction techniques : (1) procedural abstraction, (2) data abstraction, for which a user can define new data types, define associated operations, and protect them from illegal operations, and (3) syntactic abstraction to develop powerful mode of expressions and to give a method for sequencing arbitrary actions. MACLAM offers a procedure and some special functions for these abstraction techniques. The purpose of this paper is to illustrate the utilities of abstractions supported by MACLAM and to provide an informal introduction to MACLAM with some examples.

An approach to support abstraction facilities is described. In program design, abstraction techniques are very effective. But current familiar languages does not support various kinds of abstraction facilities. In order to add abstraction facilities to existing programming languages, a macro language MACLAM (A Macro Language for Abstraction Mechanisms) has been designed and implemented. MACLAM is a general-purpose and syntax-directed macro language, and attention of this language is focused on data as well as on control. The MACLAM processor is implemented as a complete pre-processor for various kinds of base language processors. MACLAM supports three kinds of abstraction techniques : (1) procedural abstraction, (2) data abstraction, for which a user can define new data types, define associated operations, and protect them from illegal operations, and (3) syntactic abstraction to develop powerful mode of expressions and to give a method for sequencing arbitrary actions. MACLAM offers a procedure and some special functions for these abstraction techniques. The purpose of this paper is to illustrate the utilities of abstractions supported by MACLAM and to provide an informal introduction to MACLAM with some examples.