Create empty implementation of pattern_matcher package for back-compa…

…bibility with DAS Gate

hyperon_das/pattern_matcher/__init__.py

@@ -0,0 +1 @@
+from .pattern_matcher import *  # noqa

hyperon_das/pattern_matcher/pattern_matcher.py

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+from abc import ABC, abstractmethod
+from typing import Any, Dict, FrozenSet, List, Optional, Set, Union
+
+from hyperon_das_atomdb import WILDCARD, AtomDB
+
+
+class PatternMatchingAnswer:
+
+    def __init__(self):
+        pass
+
+class LogicalExpression(ABC):
+
+    @abstractmethod
+    def matched(
+        self,
+        db: AtomDB,
+        answer: PatternMatchingAnswer,
+        extra_parameters: Optional[Dict[str, Any]] = None,
+    ) -> bool:
+        pass
+
+class Atom(LogicalExpression, ABC):
+
+    def __init__(self, atom_type: str):
+        pass
+
+    @abstractmethod
+    def get_handle(self, db: AtomDB) -> str:
+        pass
+
+
+class Node(Atom):
+
+    def __init__(self, node_type: str, node_name: str):
+        pass
+
+    def get_handle(self, db: AtomDB) -> str:
+        return ""
+
+    def matched(
+        self,
+        db: AtomDB,
+        answer: PatternMatchingAnswer,
+        extra_parameters: Optional[Dict[str, Any]] = None,
+    ) -> bool:
+        return True
+
+
+class Link(Atom):
+
+    def __init__(self, link_type: str, targets: List[Atom], ordered: bool):
+        pass
+
+    def get_handle(self, db: AtomDB) -> str:
+        return ""
+
+    def matched(
+        self,
+        db: AtomDB,
+        answer: PatternMatchingAnswer,
+        extra_parameters: Optional[Dict[str, Any]] = None,
+    ) -> bool:
+        return True
+
+class Variable(Atom):
+    def __init__(self, variable_name: str):
+        pass
+
+    def get_handle(self, db: AtomDB) -> str:
+        return ""
+
+    def matched(
+        self,
+        db: AtomDB,
+        answer: PatternMatchingAnswer,
+        extra_parameters: Optional[Dict[str, Any]] = None,
+    ) -> bool:
+        return True
+
+class Not(LogicalExpression):
+
+    def __init__(self, term: LogicalExpression):
+        pass
+
+    def matched(
+        self,
+        db: AtomDB,
+        answer: PatternMatchingAnswer,
+        extra_parameters: Optional[Dict[str, Any]] = None,
+    ) -> bool:
+        return True
+
+
+class Or(LogicalExpression):
+
+    def __init__(self, terms: List[LogicalExpression]):
+        pass
+
+    def matched(
+        self,
+        db: AtomDB,
+        answer: PatternMatchingAnswer,
+        extra_parameters: Optional[Dict[str, Any]] = None,
+    ) -> bool:
+        return True
+
+
+class And(LogicalExpression):
+
+    def __init__(self, terms: List[LogicalExpression]):
+        pass
+
+    def matched(
+        self,
+        db: AtomDB,
+        answer: PatternMatchingAnswer,
+        extra_parameters: Optional[Dict[str, Any]] = None,
+    ) -> bool:
+        return True