METHOD AND APPARATUS FOR FORMAT CONVERSION OF A HIERARCHICALLY STRUCTURED PAGE DESCRIPTION LANGUAGE DOCUMENT

A method and system for converting a document from a clear text representation to a binary representation. There is not a one to one correspondence between the two formats in SPDL. In order to determine what binary representation is needed for a clear text tag which can have a plurality of binary representations, it is necessary to actually process at least portions of the document for presentation (in contrast to just converting the document to a new format) in order to determine which binary representation of the tag is to be used. A stack is used to keep track of the binary elements as they are being converted. This allows for an efficient handling of the binary length encoding because the length of the binary representation of the different hierarchical levels of a document are not known until the respective hierarchical levels are encoded. An element table having pointers to sub-element linked lists can be used as a reference to determine the binary representation of the clear text tags and whether the document being converted has used proper syntax.