Coverage for /home/runner/work/tket/tket/pytket/pytket/passes/passselector.py: 100%

1# Copyright Quantinuum 

2# 

3# Licensed under the Apache License, Version 2.0 (the "License"); 

4# you may not use this file except in compliance with the License. 

5# You may obtain a copy of the License at 

6# 

7# http://www.apache.org/licenses/LICENSE-2.0 

8# 

9# Unless required by applicable law or agreed to in writing, software 

10# distributed under the License is distributed on an "AS IS" BASIS, 

11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 

12# See the License for the specific language governing permissions and 

13# limitations under the License. 

14 

15from collections.abc import Callable 

16 

17from pytket.circuit import Circuit 

18 

19from .._tket.passes import BasePass 

20 

21 

22class PassSelector: 

23 """ 

24 Collection of pytket compilation passes which are 

25 all applied to the same circuit. The result of the 

26 compilation is the best circuit as selected by a given metric. 

27 """ 

28 

29 def __init__( 

30 self, 

31 passlist: list[BasePass], 

32 score_func: Callable[[Circuit], int], 

33 ): 

34 """ 

35 Constructs a PassSelector 

36 

37 :param passlist: list of pytket compilation passes 

38 :param score_func: function to score the 

39 results of the compilation (lower scores are preferred) 

40 """ 

41 self._passlist = passlist 

42 self._score_func = score_func 

43 if len(self._passlist) < 1: 

44 raise ValueError("passlist needs to contain at least one pass") 

45 

46 def apply(self, circ: Circuit) -> Circuit: 

47 """ 

48 Compiles the given circuit with the best of the given passes. 

49 

50 :param circ: Circuit that should be compiled 

51 :return: compiled circuit 

52 """ 

53 circ_list = [circ.copy() for _ in self._passlist] 

54 

55 self._scores: list[int | None] = [] 

56 

57 for p, c in zip(self._passlist, circ_list): 

58 try: 

59 p.apply(c) 

60 self._scores.append(self._score_func(c)) 

61 except: # noqa: E722 

62 # in case of any error the pass should be ignored 

63 self._scores.append(None) 

64 

65 try: 

66 return circ_list[ 

67 self._scores.index(min(x for x in self._scores if x is not None)) 

68 ] 

69 except ValueError: 

70 raise RuntimeError("No passes have successfully run on this circuit") 

71 

72 def get_scores(self) -> list[int | None]: 

73 """ 

74 :return: scores of the circuit after compiling 

75 for each of the compilations passes 

76 """ 

77 return self._scores