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3. AN APPLICATION RECONFIGURATION FRAMEWORK 3.3. Original to Generic syntax Converter
Listing 3.4: Grammar Compiler proposed interface
interface GC {
CompilationData doCompile(byte[] grammar);
}
Listing 3.5: Parser Repository proposed interface
interface PR {
Parser storeParser(ParserID parserID, ParserInt parser, byte[]
grammar);
Parser importParser(ParserID parserID, ParserInt parser);
Iterator getIterator();
void deleteParser(String parserID);
void saveState();
}
grammars. For this, CG may make use of an outside parser generator, such as Bison [FSF08],
SableCC [GH98], JavaCC [Pro09], etc., by invoking it whenever a grammar is received. Also,
when a grammar is not valid, CG must return an error message containing information about
the problem.
Parser Repository
The Parser Repository (PR, Listing 3.5) is a parser database which manages the parsers used
by the tool to that date. It maintains a map of ParserID, which is the parser name and must
uniquely identify it, and Parser, used to call a given parser. PR provides a number of func-
tionalities to the user. These functionalities are now enumerated.
The parsers generated by the Grammar Compiler may be stored by the PR if the user has
approved them. The storeParser method saves a parser in the database, given its name,
which uniquely identifies it, the parser and its grammar definition.
If a user possesses an already built parser for a new configuration file, it is possible to im-
port that parser into the tool. The importParser method saves an external parser in the
database. The importation of external parsers is, nevertheless, conditioned by a pre-defined in-
terface which forces external parsers to implement an invocable method. This matter is further
discussed in Section 3.6.
Besides inserting parsers into the database, it is also possible to obtain an iterator for the
existing parsers in the parser repository through the getIterator method, to delete a parser
from the database with the deleteParser method and to save the state of the database by
calling the saveState method.
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