def parseMFQL(self, content):
'''
parse a MFQL source file an return a list of Statements.
@param content: the name of the file to be parsed or directly an file
object.
@type content: string || file.
@return: the list of statements.
@rtype: list<Statement>
'''
if isinstance(content, str) or isinstance(content, unicode):
stream = antlr3.ANTLRStringStream(content)
else:
stream = antlr3.ANTLRInputStream(content)
lexer = MFQLLexer(stream)
tokens = antlr3.CommonTokenStream(lexer)
parser = MFQLParser(tokens)
result = parser.stmts()
parser.eof()
validator = CompositeVisitor()
validator.addComponent(IsKeyValidator())
if isinstance(result, list):
for elem in result:
elem.walk(validator)
else:
result.walk(validator)
return result
def _secondPassVisit(self, queryPlan, props):
# debugging visitor
#tracer = TracingVisitor()
filters = FilterVisitor(self._relations, self._alu)
secondPass = CompositeVisitor()
#secondPass.addComponent(tracer)
secondPass.addComponent(filters)
for elem in queryPlan:
#tracer.printSeparation()
elem.walk(secondPass)
def parse(self, rule, inputStr):
char_stream = antlr3.ANTLRStringStream(inputStr)
lexer = MFQLLexer(char_stream)
tokens = antlr3.CommonTokenStream(lexer)
parser = MFQLParser(tokens)
rule = getattr(parser, rule)
result = rule()
parser.eof()
validator = CompositeVisitor()
validator.addComponent(IsKeyValidator())
if isinstance(result, list):
for elem in result:
elem.walk(validator)
else:
result.walk(validator)
return result
def _firstPassVisit(self, queryPlan, props):
'''
go through the complete AST and extract all definitions
@param queryPlan: the list of all queries the have been found by the
parser.
@type queryPlan: list<Statement>
'''
# debugging visitor
tracer = TracingVisitor()
# visitor that will find all streams
streams = StreamVisitor(self)
# for index extraction
# visitor that will find all relations
joinBuilder = JoinBuilder()
relations = RelationVisitor(joinBuilder, self._alu)
firstPass = CompositeVisitor()
firstPass.addComponent(tracer)
firstPass.addComponent(self)
firstPass.addComponent(streams)
firstPass.addComponent(joinBuilder)
firstPass.addComponent(relations)
for elem in queryPlan:
tracer.printSeparation()
elem.walk(firstPass)
if len(self._istreams) == 0:
raise IllegalCondition('remember what this system is about?')
# now store what we have found
self._relations = relations.getRelations()
self._inserts = relations.getInserts()
