Aster nPath Guide
As we've seen in our introduction to the power of Aster's nPath (Using Aster Express: Act 3, On the Road to nPath), the nPath function allows you to perform regular pattern matching over a sequence of rows. With it, you can find sequences of rows that match a pattern you’ve specified and easily extract information from these matched PATTERNs using SYMBOLs that represent the matched rows in the pattern.
nPath uses regular expressions because they are simple, widely understood, and flexible enough to express most search criteria. While most uses of regular expressions focus on matching patterns in strings of text; nPath enables matching patterns in sequences of rows.