Implemented factory pattern for trace transformers

src/testcrush/grammars/transformers.py

@@ -2,8 +2,9 @@
 # SPDX-License-Identifier: MIT
 
 import lark
+import pathlib
 
-from typing import Literal, Any, Iterable
+from typing import Literal, Any, Iterable, Union
 from testcrush.zoix import Fault
 from testcrush.utils import get_logger
 
@@ -312,3 +313,20 @@ def reg_and_mem(self, *reg_val_pairs: str) -> str:
         """
         reg_and_mem = f"\"{', '.join([ str(pair).strip() for pair in reg_val_pairs])}\""
         return reg_and_mem
+
+
+class TraceTransformerFactory:
+    """
+    Factory pattern for trace transformers and the corresponding grammars.
+
+    To be used as ``transformer, grammar = TraceTransformerFactory("ProcessorString")``
+    """
+    _transformers = {
+        "CV32E40P": (TraceTransformerCV32E40P, pathlib.Path("trace_cv32e40p.lark").resolve())
+    }
+
+    def __call__(self, processor_type: str) -> Union[tuple[TraceTransformerCV32E40P, pathlib.Path]]:
+        transformer, grammar = self._transformers.get(processor_type, default=(None, None))
+        if not transformer:
+            raise KeyError(f"Transformer for {processor_type} not found")
+        return transformer(), grammar