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

calculators/builder-adversary-min/run-01/calc/evaluator.py

@@ -0,0 +1,43 @@
+"""Evaluator for the calc AST.
+
+Result type rule: if the result is a whole number, return int; otherwise return float.
+Division is always true division. Division by zero raises EvalError.
+"""
+
+from calc.parser import Num, BinOp, Unary
+
+
+class EvalError(Exception):
+    pass
+
+
+def evaluate(node) -> int | float:
+    if isinstance(node, Num):
+        return node.value
+    if isinstance(node, Unary):
+        val = evaluate(node.operand)
+        if node.op == '-':
+            return _coerce(-val)
+        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 _coerce(left + right)
+        if node.op == '-':
+            return _coerce(left - right)
+        if node.op == '*':
+            return _coerce(left * right)
+        if node.op == '/':
+            if right == 0:
+                raise EvalError("Division by zero")
+            return _coerce(left / right)
+        raise EvalError(f"Unknown binary op: {node.op!r}")
+    raise EvalError(f"Unknown node type: {type(node)!r}")
+
+
+def _coerce(val: int | float) -> int | float:
+    """Return int if val is whole-valued, otherwise float."""
+    if isinstance(val, float) and val.is_integer():
+        return int(val)
+    return val