A LR-Like Analyzer Algorithm for Graphs

Abstract

The lack of linear orderings in graphs is a major obstacle in the extension of powerful syntactic analysis methods to graphs. One method to describe an ordering on a graph is the specification of a spanning ordered tree, a so-called visitation-tree. If such trees are given for all graphs occuring in a graph-grammar, for all generated graphs visitation-trees may be generated as well by the same derivation mechanism. Thus, the graphs generated by ordered graph grammars carry an implicit ordering with them, which may be reconstructed on need. We will show that such visitation-trees form a solid basis for the extension of LR-Parsing to graphs.