Research on HRegExp Applied to GML Parsing

In order to parse GML data more effectively and accurately, the homologous regular expression (abbreviated to HRegExp) which is a powerful grammar tool for recognizing strings of text is put forward. HRegExp is generated from the regular expression by rational extension and reconstruction. The syntax structure and elements internal organization of simple data type and complex data type in GML schemas can be described perfectly by using HRegExp. A universal GML parser based on HRegExp, which will provide a public platform for many GIS researches on spatial data issues, is established to implement GML data parsing. An integrative GML grammatical and semantic database, which resolves the problem of how to describe simple data type and complex data type in schemas, is also discussed in this paper. In the end, an example of GML data parsing is shown to illustrate the validity of HRegExp.