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P9327   M.G.J. van den Brand
        "Generation of language independent modular prettyprinters"


An algebraic approach to address the problem of generating prettyprinters
is described. An algebraic prettyprint generator is defined which produces
an algebraic prettyprinter for a language given its context-free grammar.
Adaption of the generated prettyprinter is possible by customizing the
generated prettyprint rules. The prettyprinter transforms the abstract
syntax tree of the text to be prettyprinted into a box-language expression.
This expression, the so-called box-term, is processed by a generic
formatter (also algebraically specified). The generated prettyprinter is
able to deal with various forms of comments. The context-free grammar may
be split into modules and, instead of generating one big prettyprinter for
such a context-free grammar, a corresponding prettyprint module is
generated for each syntax module. The collection of generated modules form
the prettyprinter for the specified language. Pretyprinters for various
languages have been generated. Among these are PASCAL, a simplified version
of LISP, and Action Semantics.