August 2003
Intermediate to advanced
624 pages
15h 3m
English
Content preview from Using XML with Legacy Business Applications
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Grammar Analysis and Description
While our discussion of CSV grammars focused strictly on the grammar of a row, our consideration of flat file grammars will focus on the logical structure of the file. Flat file record formats are usually not complex (at least in the way we will deal with them).
Before we look at the BNF, let's look at a few examples. Our sample invoice and purchase order files have the following record organization (except that the purchase order doesn't have a summary record). To focus on the structure, I use just the record IDs, and indentation shows the groupings.
HDR SHP LIN DSC SUM
The following example uses somewhat arbitrary record tags.
A010 B020 C030 D040 E050 F060 G070 H080 I090 J100
The thing that flat file formats ...