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NIST Express Working Form Programmer



Steve Clark


The Product Data Exchange Specification (PDES) is an emerging standard for the exchange of product information among various manufacturing applications. PDES includes an information model written in the Express language; other PDES-related information models are also written in Express. The National PDES Testbed at NIST has developed software to manipulate and translate Express models. This software consists of an in-memory working form and an associated Express language parser, Fed-X. The internal operation of the Fed-X parser is described. The implementation of the data abstractions which make up the Express Working Form is discussed, and specifications are given for the Working From access functions. The creation of Express language translators using Fed-X is discussed.
NIST Interagency/Internal Report (NISTIR) - 4407
Report Number


Product Data Exchange Specification (PDES), Express model, Express working form, language translator


Clark, S. (1990), NIST Express Working Form Programmer, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed June 17, 2024)


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Created April 1, 1990, Updated November 10, 2018