FEDEX(1)

NAME
fedex - EXPRESS Compiler

SYNOPSIS
fedex [ -e Express-schema-file ] [ -w warning-class ... ] [ -i warning-class ... ]

DESCRIPTION
fedex is an EXPRESS-based translator. It parses the EXPRESS language information model contained in the input EXPRESS file and sends warnings and errors to stdout.

The `-w warning-class' and `-i warning-class' options are used to enable or disable various categories of warning messages. These options are processed left-to-right, with later options overriding earlier ones. Any number of these options may appear in any order.

During the parsing of the EXPRESS file, fedex detects any problems with the input schema. These problems are reported to the user, subject to the controls imposed by any `-w' and `-i' options. If no errors are encountered, fedex terminates with an appropriate message.

OPTIONS
To see a list of options, run fedex without any arguments.

SEE ALSO

The NIST EXPRESS Working Form, R 4814, Clark, S., and Libes, D., revised, April 1992.

ISO 10303-11:1994 Industrial Automation Systems and Integration -- Product Data Representation and Exchange -- Part 11: Description Methods: The EXPRESS Language Reference Manual.

The NIST EXPRESS Toolkit - Design and Implementation, Engineering Data Management: Key to Success in a Global Market, Proc. of the 1993 ASME Intl. Computers in Engineering Conference, August 8-12, 1993, San Diego, pp. 167-180.

The NIST EXPRESS Toolkit: Using Applications, R 5206, Libes, D., June 1993.

d-X: The NIST EXPRESS Translator, R 4822, Libes, D., April 1992.

BUGS
Some Express language constructs are accepted by fedex but are not represented in the Express Working Form, and so are not available during the output pass. These constructs include cardinality expressions, MAP directives, and supertype expressions. In addition, PRIVATE directives and WITH statements are represented in the Working Form, but are ignored during symbol lookup. This may produce spurious warnings about undefined or multiply defined identifiers.

According to the rules of EXPRESS (STEP Part 11, Section 9.2.4.5), the AND operator has a higher precedence than ANDOR. fedex considers them to have an equal level of precedence and processes them from left to right. A work around would be to use paretheses around all AND operators appearing in an expression.

Expressions are not `type'd properly: although an expression's type can be derived from its components, this has not been implemented. This can result in spurious warnings. A notable example occurs when a complex expression used as a loop control (WHILE or UNTIL) does not appear to compute a boolean result simply because no type has been computed for the expression.

NOTE

All NISTIR documents may be obtained through the National Technical Information Service (NTIS), Springfield VA 22161, USA. Postscript files may be obtained from the STEP Class Library web page (http://www.nist.gov/scl), the Manufacturing Systems Integration Division publications page (http://www.mel.nist.gov/msidlibrary/pubs.htm) or by anonymous ftp from ftp.cme.nist.gov (see pub/subject/sc4/national/usa/nist/docs/readme.txt to determine the appropriate file to download).