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4. AN IMPLEMENTATION 4.5. Original to Generic syntax Converter
user must alter the grammar to recognize the text parts which failed to be parsed, until a parser
which recognizes the whole file is generated.
The initial plan was for a graphical interface to be launched whenever a file could not be
parsed by any parser in the database. This interface would display useful information to the
user such as the graphical representation of the configuration file in XML, grammar navigator
and highlighted configuration file based on its parsed and not parsed parts. UI would also
allow the user to define a grammar without having to manually program it, resorting to the
selection of configuration file pieces and assigning meanings to them, in an interactive way.
However, the implementation of the graphical interface will only take place during the inte-
gration of the tool with VIRTU.
4.5.2 Configuration File Parser
When the Configuration File Parser is summoned for the first time, it initiates the
Parser Repository.
The doParse(String fileName) method calls the doParse(String fileName,
Parser parser) method for every available parser in the Parser Repository and logs
the resulting ParsingData objects in a map, where the entry key is the used Parser. This
method returns the map generated in this way.
The doParse(String fileName, Parser parser) method, in turn, treats a config-
uration file with a parser at a time. If parser is an InternalParser, its parse method is
invoked using the Java reflex API and the return, a list of Node objects (Listing 4.1), is sent
to the Code Generator to be passed to generic XML. Thrown exceptions during parse time
mean that a file was not entirely recognized. The exceptions caught at parsing time contain
the position where the recognized block starts and ends. These exceptions are analysed to re-
trieve that information. The percentage of recognized file is calculated based on the limits of
every parsed block. In the end, a ParsingData object containing the parsing percentage, the
recognized blocks, characterized by their start and end points, together with the XML of the
respective blocks, is returned.
4.5.3 Parser Repository
The Parser Repository holds a map of Parser objects corresponding to the available
parsers. When PR is initiated, it gets the last saved state by loading the parser map to memory.
The storeParser method creates a Parser object from a string containing the name
of the parser, and the ExternalParserInterface which contains the parser. An optional
grammarFile can be passed, in case the user wants to merge the grammar with the Parser
so that it is available in the future. If the grammarFile argument is not null, the grammar
must be stored in the grammar directory, with the same name as the parser. The Parser is
then inserted in the Parser map. The importParser does a similar job in inserting a parser
in the database, but for external parsers.
PR also implements methods for getting the parser map iterator, getIterator and to
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