A Novel Parser Design Algorithm Based on Artificial Ants

TL;DR

This paper introduces a new parser design using Ant Colony Optimization that efficiently handles ambiguous grammars and finds optimal parsing paths by mimicking ant behavior, eliminating complex set calculations.

Contribution

It presents a novel bottom-up parser algorithm based on artificial ants that directly uses ambiguous grammars and discovers optimal parsing paths through pheromone-guided search.

Findings

Effective parsing of ambiguous and redundant grammars.

Ability to determine string membership in the language.

Finds shortest derivation paths when multiple options exist.

Abstract

This article presents a unique design for a parser using the Ant Colony Optimization algorithm. The paper implements the intuitive thought process of human mind through the activities of artificial ants. The scheme presented here uses a bottom-up approach and the parsing program can directly use ambiguous or redundant grammars. We allocate a node corresponding to each production rule present in the given grammar. Each node is connected to all other nodes (representing other production rules), thereby establishing a completely connected graph susceptible to the movement of artificial ants. Each ant tries to modify this sentential form by the production rule present in the node and upgrades its position until the sentential form reduces to the start symbol S. Successful ants deposit pheromone on the links that they have traversed through. Eventually, the optimum path is discovered by the links carrying maximum amount of pheromone concentration. The design is simple, versatile, robust and effective and obviates the calculation of the above mentioned sets and precedence relation tables. Further advantages of our scheme lie in i) ascertaining whether a given string belongs to the language represented by the grammar, and ii) finding out the shortest possible path from the given string to the start symbol S in case multiple routes exist.