This monograph is concerned with the problem of getting computers to transform formal language definitions into compilers. Its purpose is to demonstrate how certain simple theoretical ideas can be used to generate compilers and even compiler generators. As the title suggests, a realistic assessment of the relationship between the complexity of realistic compilation and the relative simplicity studied in theoretical work is attempted. The monograph contains an overview of existing compiler generators. The CERES '83 compiler generator, developed by Neil D. Jones and the author, is described in detail. The CERES system is based on the idea of composing language definitions and it serves as an example of a powerful novel "bootstrapping" technique by which one can generate compiler generators as well as compilers by considering a compiler generator to be, in a sense which is made mathematically precise, a special kind of compiler. The core of the CERES system is a two-page-long machine generated compiler generator. The approach uses ideas from denotational semantics and many-sorted algebra and connects them with novel ideas about how to treat programs and language definitions as data. Considerable effort has been made to present the necessary theory in a manner suitable for readers who have some practical experience but not necessarily a theoretical background in semantics.

This monograph is concerned with the problem of getting computers to transform formal language definitions into compilers. Its purpose is to demonstrate how certain simple theoretical ideas can be used to generate compilers and even compiler generators. As the title suggests, a realistic assessment of the relationship between the complexity of realistic compilation and the relative simplicity studied in theoretical work is attempted. The monograph contains an overview of existing compiler generators. The CERES '83 compiler generator, developed by Neil D. Jones and the author, is described in detail. The CERES system is based on the idea of composing language definitions and it serves as an example of a powerful novel "bootstrapping" technique by which one can generate compiler generators as well as compilers by considering a compiler generator to be, in a sense which is made mathematically precise, a special kind of compiler. The core of the CERES system is a two-page-long machine generated compiler generator. The approach uses ideas from denotational semantics and many-sorted algebra and connects them with novel ideas about how to treat programs and language definitions as data. Considerable effort has been made to present the necessary theory in a manner suitable for readers who have some practical experience but not necessarily a theoretical background in semantics.

Standard ML is a general-purpose programming language designed for large projects. This book provides a formal definition of Standard ML for the benefit of all concerned with the language, including users and implementers. Because computer programs are increasingly required to withstand rigorous analysis, it is all the more important that the language in which they are written be defined with full rigor.One purpose of a language definition is to establish a theory of meanings upon which the understanding of particular programs may rest. To properly define a programming language, it is necessary to use some form of notation other than a programming language. Given a concern for rigor, mathematical notation is an obvious choice. The authors have defined their semantic objects in mathematical notation that is completely independent of Standard ML.In defining a language one must also define the rules of evaluation precisely--that is, define what meaning results from evaluating any phrase of the language. The definition thus constitutes a formal specification for an implementation. The authors have developed enough of their theory to give sense to their rules of evaluation.The Definition of Standard ML is the essential point of reference for Standard ML. Since its publication in 1990, the implementation technology of the language has advanced enormously and the number of users has grown. The revised edition includes a number of new features, omits little-used features, and corrects mistakes of definition.