Initial commit - fix problems & refactor code

core/environment.py

@@ -0,0 +1,54 @@
+from __future__ import annotations
+from typing import Any, Callable, Optional
+from string import whitespace
+
+from core.primitives.symbol import symbolKey, isSymbol
+from core.printer import Representation
+from core.primitives.list import NIL
+
+class Environment:
+    """Environment for variable bindings with lexical scoping."""
+
+    frame: dict[str, Any]
+    parent: Environment | None
+
+    def __init__(self, parent: Environment | None) -> None:
+        self.frame: dict[str, Any] = {}
+        self.parent: Environment | None = parent
+
+    def add(self, symbol_key: Any, value: Any) -> None:
+        """Add a new binding to the current environment frame."""
+        self.frame[symbolKey(symbol_key)] = value
+
+    def set(self, symbol_key: Any, value: Any) -> None:
+        """Set a binding in the environment chain."""
+        key: str = symbolKey(symbol_key)
+        currentEnvironment: Environment = self
+        while currentEnvironment is not None:
+            if key in currentEnvironment.frame:
+                currentEnvironment.frame[key] = value
+                return
+            assert currentEnvironment is Environment
+            currentEnvironment = currentEnvironment.parent
+        raise SyntaxError(f"no such symbol: {key}")
+
+    def get(self, symbol_key: Any) -> Any:
+        """Get a binding from the environment chain."""
+        key: str = symbolKey(symbol_key)
+        currentEnvironment: Environment | None = self
+        while currentEnvironment is not None:
+            if key in currentEnvironment.frame:
+                return currentEnvironment.frame[key]
+            currentEnvironment = currentEnvironment.parent
+        return symbol_key
+
+EVAL_NIL: Callable[[], Any] = lambda: NIL
+ENV: Environment = Environment(None)
+
+MEANINGFUL: str = "\"();'"
+IGNORE: str = whitespace + ","
+
+RepresentateAST: Callable[[Any], str] = lambda value: (
+    value if type(value) is str and not isSymbol(value) else Representation(value)
+)
+TCO: bool = True