1824	 APAREL-A Parse-Request Language	 APAREL is described this language is an extension to an algorithmic language PL I that provides the pattern-matching capabilities normally found only in special purpose languages such as SNOBOL and TMG. This capability is provided through parse-requests stated in a BNF-like format. These parse-requests form their own programming language with special sequencing rules. Upon successfully completing a parse-request an associated piece of PL I code is executed. This code has available for use as normal PL I strings the various pieces at all levels of the parse. It also has available as normal PL I variables the information concerning which of the various alternatives were successful. Convenient facilities for multiple input-output streams the initiation of sequences of parse-requests as a subroutine and parse-time semantic checks are also included. APAREL has proven convenient in building a powerful SYNTAX and FUNCTION macro system an algebraic language preprocessor debugging system an on-line command parser a translator for Dataless Programming and as a general string manipulator. text processing string processing symbol manipulation PL I BNF syntax parser translator pattern matching
