hwt/hdl/statements.py
def _merge_statements(statements: List["HdlStatement"])\
            -> Tuple[List["HdlStatement"], int]:
        """
        Merge statements in list to remove duplicated if-then-else trees

        :return: tuple (list of merged statements, rank decrease due merging)
        :note: rank decrease is sum of ranks of reduced statements
        :attention: statement list has to me mergable
        """
        order = {}
        for i, stm in enumerate(statements):
            order[stm] = i

        new_statements = []
        rank_decrease = 0

        for rank, stms in groupedby(statements, lambda s: s.rank):
            if rank == 0:
                new_statements.extend(stms)
            else:
                if len(stms) == 1:
                    new_statements.extend(stms)
                    continue

                # try to merge statements if they are same condition tree
                for iA, stmA in enumerate(stms):
                    if stmA is None:
                        continue

                    for iB, stmB in enumerate(islice(stms, iA + 1, None)):
                        if stmB is None:
                            continue

                        if stmA._is_mergable(stmB):
                            rank_decrease += stmB.rank
                            stmA._merge_with_other_stm(stmB)
                            stms[iA + 1 + iB] = None
                            new_statements.append(stmA)
                        else:
                            new_statements.append(stmA)
                            new_statements.append(stmB)

        new_statements.sort(key=lambda stm: order[stm])
        return new_statements, rank_decrease
def _merge_statements(statements: List["HdlStatement"])\
            -> Tuple[List["HdlStatement"], int]:
        """
        Merge statements in list to remove duplicated if-then-else trees

        :return: tuple (list of merged statements, rank decrease due merging)
        :note: rank decrease is sum of ranks of reduced statements
        :attention: statement list has to me mergable
        """
        order = {}
        for i, stm in enumerate(statements):
            order[stm] = i

        new_statements = []
        rank_decrease = 0

        for rank, stms in groupedby(statements, lambda s: s.rank):
            if rank == 0:
                new_statements.extend(stms)
            else:
                if len(stms) == 1:
                    new_statements.extend(stms)
                    continue

                # try to merge statements if they are same condition tree
                for iA, stmA in enumerate(stms):
                    if stmA is None:
                        continue

                    for iB, stmB in enumerate(islice(stms, iA + 1, None)):
                        if stmB is None:
                            continue

                        if stmA._is_mergable(stmB):
                            rank_decrease += stmB.rank
                            stmA._merge_with_other_stm(stmB)
                            stms[iA + 1 + iB] = None
                            new_statements.append(stmA)
                        else:
                            new_statements.append(stmA)
                            new_statements.append(stmB)

        new_statements.sort(key=lambda stm: order[stm])
        return new_statements, rank_decrease
Merge statements in list to remove duplicated if-then-else trees

        :return: tuple (list of merged statements, rank decrease due merging)
        :note: rank decrease is sum of ranks of reduced statements
        :attention: statement list has to me mergable