In general, it reads an input file and copies it to an output file, while performing certain transformations to data as specified by a set of patterns set by user. Can be used to do things done by Unix utilities cpp, grep, sed, awk, or strings, and as a macro processor, but is far more general than cpp or m4 because it imposes no syntax for what a macro call looks like. Unlike utilities like sed or awk, it can deal with patterns that span multiple lines, with nested constructs, and can use multiple sets of rules in different contexts. It makes extensive use of pattern matching somewhat related to that used in ML and Prolog. Ronin Software Group.
Tables are a vital data representation method.