AToMPM/mt/ptcal/pytcore/rules/query.py

'''This file is part of AToMPM - A Tool for Multi-Paradigm Modelling
Copyright 2011 by the AToMPM team and licensed under the LGPL
See COPYING.lesser and README.md in the root of this project for full details'''

from ..tcore.composer import Composer
from ..tcore.matcher import Matcher
from ..tcore.iterator import Iterator


class Query(Composer):
    '''
        Finds a match for the LHS.
    '''
    def __init__(self, LHS):
        '''
            Finds a match for the LHS.
            @param LHS: The pre-condition pattern (LHS + NACs).
        '''
        super(Query, self).__init__()
        self.M = Matcher(condition=LHS, max=1)
        self.I = Iterator(max_iterations=1)

    def packet_in(self, packet):
        self.exception = None
        self.is_success = False
        # Match
        packet = self.M.packet_in(packet)
        if not self.M.is_success:
            self.exception = self.M.exception
            return packet
        # Choose the only match
        packet = self.I.packet_in(packet)
        if not self.I.is_success:
            # Clean the packet: required since there is no Rewriter in a Query
            if  len(packet.match_sets[self.I.condition].matches) == 0:
                del packet.match_sets[self.I.condition]
            self.exception = self.I.exception
            return packet
        # Output success packet
        self.is_success = True
        return packet

class CQuery2(Composer):
    '''
        Finds a match for the LHS.
    '''
    def __init__(self, LHS, innerQuery):
        '''
            Finds a match for the LHS.
            @param LHS: The pre-condition pattern (LHS + NACs).
        '''
        super(CQuery2, self).__init__()
        self.M = Matcher(condition=LHS)
        self.I = Iterator()
        self.innerQuery=innerQuery

    def packet_in(self, packet):
        self.exception = None
        self.is_success = False
        # Match
        packet = self.M.packet_in(packet)
        if not self.M.is_success:
            self.exception = self.M.exception
            return packet

        # Choose the first match
        packet = self.I.packet_in(packet)
        if not self.I.is_success:
            self.exception = self.I.exception
            return packet

        while True:

            packet = self.innerQuery.packet_in(packet)
            if self.innerQuery.is_success:
                if self.innerQuery.exception:
                    self.exception = self.innerQuery.exception
                    return packet

                # Choose another match
                packet = self.I.next_in(packet)
                # No more iterations are left
                if not self.I.is_success:
                    if self.I.exception:
                        self.exception = self.I.exception
                    else:
                        # Output success packet
                        self.is_success = False
                    return packet
            else:
                self.is_success=True
                return packet

class CQuery3(Composer):
    '''
        Finds a match for the LHS.
    '''
    def __init__(self, LHS, innerQuery, secondInnerQuery):
        '''
            Finds a match for the LHS.
            @param LHS: The pre-condition pattern (LHS + NACs).
        '''
        super(CQuery3, self).__init__()
        self.M = Matcher(condition=LHS)
        self.I = Iterator()
        self.innerQuery=innerQuery
        self.secondInnerQuery=secondInnerQuery

    def packet_in(self, packet):
        self.exception = None
        self.is_success = False
        # Match
        packet = self.M.packet_in(packet)
        if not self.M.is_success:
            self.exception = self.M.exception
            return packet

        # Choose the first match
        packet = self.I.packet_in(packet)
        if not self.I.is_success:
            self.exception = self.I.exception
            return packet

        while True:

            packet = self.innerQuery.packet_in(packet)
            if self.innerQuery.is_success:
                if self.innerQuery.exception:
                    self.exception = self.innerQuery.exception
                    return packet

                # Choose another match
                packet = self.I.next_in(packet)
                # No more iterations are left
                if not self.I.is_success:
                    if self.I.exception:
                        self.exception = self.I.exception
                    else:
                        self.is_success = False
                    return packet
            else:

                packet = self.secondInnerQuery.packet_in(packet)
                if self.secondInnerQuery.is_success:
                    if self.secondInnerQuery.exception:
                        self.exception = self.secondInnerQuery.exception
                        return packet
                    packet = self.I.next_in(packet)
                    if not self.I.is_success:
                        if self.I.exception:
                            self.exception = self.I.exception
                        else:
                            self.is_success = False
                        return packet
                else:
                    self.is_success=True
                    return packet