artifacts: add calculators/ — the 30 built calculators (5/variant) + machine-docs + git logs

calculators/builder-adversary-stateless/run-03/calc/evaluator.py

@@ -0,0 +1,34 @@
+"""Evaluator: walks the AST produced by calc.parser and returns a numeric result."""
+
+from __future__ import annotations
+from .parser import Num, BinOp, Unary
+
+
+class EvalError(Exception):
+    pass
+
+
+def evaluate(node) -> int | float:
+    """Recursively evaluate an AST node and return int or float."""
+    if isinstance(node, Num):
+        return node.value
+    if isinstance(node, Unary):
+        operand = evaluate(node.operand)
+        if node.op == "-":
+            return -operand
+        raise EvalError(f"unknown unary op: {node.op!r}")
+    if isinstance(node, BinOp):
+        left = evaluate(node.left)
+        right = evaluate(node.right)
+        if node.op == "+":
+            return left + right
+        if node.op == "-":
+            return left - right
+        if node.op == "*":
+            return left * right
+        if node.op == "/":
+            if right == 0:
+                raise EvalError("division by zero")
+            return left / right
+        raise EvalError(f"unknown binary op: {node.op!r}")
+    raise EvalError(f"unknown node type: {type(node).__name__!r}")