org.apache.pig.parser
Classes 
DryRunGruntParser
LogicalPlanBuilder
PigParserNode
PigParserNode.InvocationPoint
PigParserNodeAdaptor
QueryParserDriver
QueryParserFileStream
QueryParserStreamUtil
QueryParserStringStream
QueryParserUtils
SourceLocation
StreamingCommandUtils
Exceptions 
DuplicatedSchemaAliasException
InvalidCommandException
InvalidPathException
InvalidScalarProjectionException
NonProjectExpressionException
ParserException
ParserValidationException
PigRecognitionException
PlanGenerationFailureException
UndefinedAliasException