Source code for pm4py.objects.process_tree.utils.regex

'''
    This file is part of PM4Py (More Info: https://pm4py.fit.fraunhofer.de).

    PM4Py is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    PM4Py is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with PM4Py.  If not, see <https://www.gnu.org/licenses/>.
'''
from pm4py.objects.process_tree import obj as pt_operator
from pm4py.util.regex import SharedObj, get_new_char


[docs]def pt_to_regex(tree, rec_depth=0, shared_obj=None, parameters=None): """ Transforms a process tree to a regular expression NB: The conversion is not yet working with trees containing an AND and/or an OR operator! Parameters ------------ tree Process tree parameters Possible parameters of the algorithm """ if parameters is None: parameters = {} if shared_obj is None: shared_obj = SharedObj() stru = "" if tree.operator is not None: contains_tau = len(list(child for child in tree.children if child.operator is None and child.label is None)) > 0 children_rep = [] for child in tree.children: rep, shared_obj = pt_to_regex(child, rec_depth=rec_depth + 1, shared_obj=shared_obj, parameters=parameters) children_rep.append(rep) if tree.operator == pt_operator.Operator.SEQUENCE: children_rep = [x for x in children_rep if not x is None] stru = "(" + "".join(children_rep) + ")" elif tree.operator == pt_operator.Operator.XOR: children_rep = [x for x in children_rep if not x is None] stru = "(" + "|".join(children_rep) + ")" if contains_tau: stru = "(" + stru + "?)" elif tree.operator == pt_operator.Operator.LOOP: children_rep = [x for x in children_rep if not x is None] if len(children_rep) == 1: stru = "(" + children_rep[0] + ")+" else: stru = "(" + "".join(children_rep) + ")*" + children_rep[0] elif tree.operator == pt_operator.Operator.PARALLEL: raise Exception("the conversion is not yet working with trees containing an AND and/or an OR operator!") elif tree.operator == pt_operator.Operator.OR: raise Exception("the conversion is not yet working with trees containing an AND and/or an OR operator!") elif tree.label is not None: if tree.label not in shared_obj.mapping_dictio: get_new_char(tree.label, shared_obj) stru = shared_obj.mapping_dictio[tree.label] elif tree.label is None: return None, shared_obj if rec_depth == 0: ret = "^" + stru + "$", shared_obj.mapping_dictio # print(ret) return ret return stru, shared_obj