THE HEART OF IGES

This paper describes the problems and complexity of implementing an in terpreter for IGES. IGES (the Initial Graphics Exchange Standard) is a n attempt to define a language that can specify geometrical, electrica l and mechanical specifications with a uniform syntax. The syntax of I GES is sketched first. This is followed by a short review of the primi tives available within IGES. The interior of the interpreter is presen ted next with particular attention paid to the implementation of the m acro language residing inside of IGES.