This paper describes the design and implementation of a tool for creating language processors, in particular, translator generators. The purpose of this tool is to allow the fast implementation of (non-production quality) translators for any language, however exotic, for which a grammar can be written, and to generate compiler phases with “hooks” which show the compiling process in action for use in compiler construction courses. The emphasis is on a user-friendly metalanguage which is consistent for the various phases of the parameterized tool. Use of the tool in a graduate compiler construction course revealed the strengths of this metalanguage as well as providing a test site for other improvements and further development of the tool.

Similarity measures between strings (finite-length sequences of symbols) are extended to apply to sets of strings in an intuitive way which also preserves some of the desired properties of the initial similarity measure. Two quite different measures are used in the examples: the first for applications where numerical computation of pointwise similarity is needed; the second for applications which depend more heavily on substring similarity. It is presumed throughout that alphabets may be nondenumerable; in particular, the unit interval [0, 1] is used as the alphabet in the examples.