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Argument Bindings and Macro Evaluation in XDE

IP.com Disclosure Number: IPCOM000034572D
Original Publication Date: 1989-Mar-01
Included in the Prior Art Database: 2005-Jan-27

Publishing Venue

IBM

Related People

Authors:
Gest, SB Wymore, FW [+details]

Abstract

XDE is an advanced software development environment targeted for the IBM RT PC* running IBM's proprietary UNIX** operating system AIX***. This paper will describe three aspects of macro expansion in the XDE command language which together combine to make a unique and powerful facility. The three aspects are: 1) argument binding at parse time, 2) the recursive evaluation of a script which may in turn cause further recursive evaluation, and 3) the macro rescan facility as part of the normal evaluation algorithm. Most macro processors do argument substitution by simple textual replacement at the time the macro is expanded. XDE's macro argument binding is done at parse time by pruning and replacing sub-parse trees. A distinction is made between a macro and a script.