Gobo Eiffel Lex PreviousNext

Gobo Eiffel Lex is a tool for generating Eiffel programs that perform pattern-matching on text. Gelex reads a given input file for the description of the scanner to be generated. The description is in the form of pairs of regular expressions and Eiffel code, called rules. Gelex generates as output an Eiffel class equipped with routines to analyze input text for occurrences of the regular expressions. Whenever one is found, the corresponding Eiffel code is executed.

This documentation is structured as follows:

Introduction to Gelex
Basic concepts for understanding gelex.
Stages in Using Gelex
Steps to follow to produce a working scanner.
Some Simple Examples
Simple explained examples.
Scanner Description File
Format of gelex input file.
The Generated Scanner
Description of the generated scanner class.
Command-line options and %option directives.
The extended regular expressions used by gelex.
Matching Rules
Rules for determining what has been matched.
Start Conditions
Introducing context into your scanners, managing "mini-scanners".
How to specify what to do when a pattern is matched.
The flat-short form of class YY_SCANNER.
Gelex limitations, bugs and other deficiencies.
See Also
Bibliographical references, related resources and acknowledgments.
Downloading Instructions
License agreement and downloading instructions.

Copyright 1998, Eric Bezault
Last Updated: 18 May 1998