unify terminal representations

Author: bygu4

pyformlang/cfg/cfg_variable_converter.py

@@ -2,55 +2,56 @@
 
 from typing import Dict, List, AbstractSet, Tuple, Optional, Hashable
 
-from ..objects.cfg_objects import Variable, CFGObjectConvertible
+from ..objects.formal_object import FormalObject
+from ..objects.cfg_objects import Variable
 
 
 class CFGVariableConverter:
     """A CFG Variable Converter"""
 
     def __init__(self,
-                 states: AbstractSet[CFGObjectConvertible],
-                 stack_symbols: AbstractSet[CFGObjectConvertible]) -> None:
+                 states: AbstractSet[FormalObject],
+                 stack_symbols: AbstractSet[FormalObject]) -> None:
         self._counter = 0
-        self._inverse_states_d: Dict[CFGObjectConvertible, int] = {}
+        self._inverse_states_d: Dict[FormalObject, int] = {}
         self._counter_state = 0
         for self._counter_state, state in enumerate(states):
             self._inverse_states_d[state] = self._counter_state
-            state.index_cfg_converter = self._counter_state
+            state.index = self._counter_state
         self._counter_state += 1
-        self._inverse_stack_symbol_d: Dict[CFGObjectConvertible, int] = {}
+        self._inverse_stack_symbol_d: Dict[FormalObject, int] = {}
         self._counter_symbol = 0
         for self._counter_symbol, symbol in enumerate(stack_symbols):
             self._inverse_stack_symbol_d[symbol] = self._counter_symbol
-            symbol.index_cfg_converter = self._counter_symbol
+            symbol.index = self._counter_symbol
         self._counter_symbol += 1
         self._conversions: List[List[List[Tuple[bool, Optional[Variable]]]]] \
             = [[[(False, None) for _ in range(len(states))]
                 for _ in range(len(stack_symbols))] for _ in
                range(len(states))]
 
-    def _get_state_index(self, state: CFGObjectConvertible) -> int:
+    def _get_state_index(self, state: FormalObject) -> int:
         """Get the state index"""
-        if state.index_cfg_converter is None:
+        if state.index is None:
             if state not in self._inverse_states_d:
                 self._inverse_states_d[state] = self._counter_state
                 self._counter_state += 1
-            state.index_cfg_converter = self._inverse_states_d[state]
-        return state.index_cfg_converter
+            state.index = self._inverse_states_d[state]
+        return state.index
 
-    def _get_symbol_index(self, symbol: CFGObjectConvertible) -> int:
+    def _get_symbol_index(self, symbol: FormalObject) -> int:
         """Get the symbol index"""
-        if symbol.index_cfg_converter is None:
+        if symbol.index is None:
             if symbol not in self._inverse_stack_symbol_d:
                 self._inverse_stack_symbol_d[symbol] = self._counter_symbol
                 self._counter_symbol += 1
-            symbol.index_cfg_converter = self._inverse_stack_symbol_d[symbol]
-        return symbol.index_cfg_converter
+            symbol.index = self._inverse_stack_symbol_d[symbol]
+        return symbol.index
 
     def to_cfg_combined_variable(self,
-                                 state0: CFGObjectConvertible,
-                                 stack_symbol: CFGObjectConvertible,
-                                 state1: CFGObjectConvertible) -> Variable:
+                                 state0: FormalObject,
+                                 stack_symbol: FormalObject,
+                                 state1: FormalObject) -> Variable:
         """ Conversion used in the to_pda method """
         i_stack_symbol, i_state0, i_state1 = self._get_indexes(
             stack_symbol, state0, state1)
@@ -74,19 +75,19 @@ def _create_new_variable(self,
         return temp
 
     def set_valid(self,
-                  state0: CFGObjectConvertible,
-                  stack_symbol: CFGObjectConvertible,
-                  state1: CFGObjectConvertible) -> None:
+                  state0: FormalObject,
+                  stack_symbol: FormalObject,
+                  state1: FormalObject) -> None:
         """Set valid"""
         i_stack_symbol, i_state0, i_state1 = self._get_indexes(
             stack_symbol, state0, state1)
         prev = self._conversions[i_state0][i_stack_symbol][i_state1]
         self._conversions[i_state0][i_stack_symbol][i_state1] = (True, prev[1])
 
     def is_valid_and_get(self,
-                         state0: CFGObjectConvertible,
-                         stack_symbol: CFGObjectConvertible,
-                         state1: CFGObjectConvertible) -> Optional[Variable]:
+                         state0: FormalObject,
+                         stack_symbol: FormalObject,
+                         state1: FormalObject) -> Optional[Variable]:
         """Check if valid and get"""
         i_state0 = self._get_state_index(state0)
         i_stack_symbol = self._get_symbol_index(stack_symbol)
@@ -102,9 +103,9 @@ def is_valid_and_get(self,
         return current[1]
 
     def _get_indexes(self,
-                     stack_symbol: CFGObjectConvertible,
-                     state0: CFGObjectConvertible,
-                     state1: CFGObjectConvertible) \
+                     stack_symbol: FormalObject,
+                     state0: FormalObject,
+                     state1: FormalObject) \
             -> Tuple[int, int, int]:
         i_state0 = self._get_state_index(state0)
         i_stack_symbol = self._get_symbol_index(stack_symbol)

pyformlang/cfg/tests/test_terminal.py

@@ -34,5 +34,5 @@ def test_eq(self):
         assert "A" == Terminal("A")
         assert Variable(1) == 1
         assert Epsilon() == FAEpsilon()
-        assert Terminal("ABC") != Symbol("ABC")
+        assert Terminal("ABC") == Symbol("ABC")
         assert State("S") != Variable("S")

pyformlang/objects/base_epsilon.py

@@ -3,11 +3,12 @@
 from typing import Any
 
 from .formal_object import FormalObject
+from .base_terminal import BaseTerminal
 
 EPSILON_SYMBOLS = ["epsilon", "ɛ"]
 
 
-class BaseEpsilon(FormalObject):
+class BaseEpsilon(BaseTerminal):
     """ An epsilon transition
 
     Examples

pyformlang/objects/base_terminal.py

@@ -0,0 +1,24 @@
+""" General terminal representation """
+
+from typing import Any
+from abc import abstractmethod
+
+from .formal_object import FormalObject
+
+
+class BaseTerminal(FormalObject):
+    """ General terminal representation """
+
+    def __eq__(self, other: Any) -> bool:
+        if isinstance(other, BaseTerminal):
+            return self.value == other.value
+        if isinstance(other, FormalObject):
+            return False
+        return self.value == other
+
+    def __hash__(self) -> int:
+        return super().__hash__()
+
+    @abstractmethod
+    def __repr__(self):
+        raise NotImplementedError

pyformlang/objects/cfg_objects/__init__.py

@@ -5,12 +5,10 @@
 from .terminal import Terminal
 from .epsilon import Epsilon
 from .production import Production
-from .cfg_object_convertible import CFGObjectConvertible
 
 
 __all__ = ["CFGObject",
            "Variable",
            "Terminal",
            "Epsilon",
-           "Production",
-           "CFGObjectConvertible"]
+           "Production"]

pyformlang/objects/cfg_objects/cfg_object.py

@@ -2,10 +2,10 @@
 
 from abc import abstractmethod
 
-from .cfg_object_convertible import CFGObjectConvertible
+from ..formal_object import FormalObject
 
 
-class CFGObject(CFGObjectConvertible):
+class CFGObject(FormalObject):
     """ An object in a CFG
 
     Parameters

pyformlang/objects/cfg_objects/cfg_object_convertible.py

@@ -1,24 +1,12 @@
 """ A terminal in a CFG """
 
-from typing import Any
-
 from .cfg_object import CFGObject
-from ..formal_object import FormalObject
+from ..base_terminal import BaseTerminal
 
 
-class Terminal(CFGObject):
+class Terminal(BaseTerminal, CFGObject):
     """ A terminal in a CFG """
 
-    def __eq__(self, other: Any) -> bool:
-        if isinstance(other, Terminal):
-            return self.value == other.value
-        if isinstance(other, FormalObject):
-            return False
-        return self.value == other
-
-    def __hash__(self) -> int:
-        return super().__hash__()
-
     def __repr__(self) -> str:
         return f"Terminal({self})"
 

pyformlang/objects/cfg_objects/terminal.py

@@ -5,11 +5,10 @@
 from typing import Any
 
 from .finite_automaton_object import FiniteAutomatonObject
-from ..cfg_objects import CFGObjectConvertible
 from ..formal_object import FormalObject
 
 
-class State(CFGObjectConvertible, FiniteAutomatonObject):
+class State(FiniteAutomatonObject):
     """ A state in a finite automaton
 
     Parameters

pyformlang/objects/finite_automaton_objects/state.py

@@ -2,13 +2,11 @@
 This module describe a symbol in a finite automaton.
 """
 
-from typing import Any
-
 from .finite_automaton_object import FiniteAutomatonObject
-from ..formal_object import FormalObject
+from ..base_terminal import BaseTerminal
 
 
-class Symbol(FiniteAutomatonObject):
+class Symbol(BaseTerminal, FiniteAutomatonObject):
     """ A symbol in a finite automaton
 
     Parameters
@@ -23,15 +21,5 @@ class Symbol(FiniteAutomatonObject):
     A
     """
 
-    def __eq__(self, other: Any) -> bool:
-        if isinstance(other, Symbol):
-            return self.value == other.value
-        if isinstance(other, FormalObject):
-            return False
-        return self.value == other
-
-    def __hash__(self) -> int:
-        return super().__hash__()
-
     def __repr__(self) -> str:
         return f"Symbol({self})"