The use of source-to-source program transformations has proved valuable in improving program performance. The concept of program manipulation is elucidated by describing its role in both conventional optimization and high level modification of conditional, looping, and procedure structures. An example program fragment written in an Algol-like language is greatly improved by transformations enabled by a user-provided assertion about a data array. A compilation model based on the use of source-to-source program transformations is used to provide a framework for discussing issues of code generation, compilation of high level languages such as APL, and eliminating overhead commonly associated with modular structured programming. Application of the compilation model to several different languages is discussed.

We treat a program as an object of manipulation, determine items of program constancy, and simplify the program based on the constancy. Some motivation for program manipulation is presented, along with two examples of “higher level optimization” written in an Algol-like language. A collection of program transformations and a model of the compilation process in terms of source-to-source transformations are presented. Finally a description of the application of these ideas to an existing programming language is given.

The University of Dayton, located in Dayton, Ohio, is a “medium-sized, private, coeducational school located in the heart of the Midwest,” with a full-time student body of sixty-five hundred. The University, which is also the fifth largest Catholic college in the country, “includes three schools and the college, offering a large selection of study ranging from art and philosophy to geology and computer science.&rdquo

CUE, an input interface system which permits the computer to utilize natural but restricted English as input, is presented. In addition, an experimental model for CUE, Proto-RELADES, which can "understand" and execute English sentences about the content of the library at IBM's Boston Programming Center is described. These sentences can be query, command, or conditional sentences. The linguistic component of the system is based on a transformational grammar of English that performs a full syntactic and semantic analysis of each input sentence and translates it into relevant computer operations. The capabilities and limitations of this system are described.