another save

lab4/gp/primitive.py

@@ -0,0 +1,35 @@
+from dataclasses import dataclass
+from typing import Callable, Sequence
+
+from .types import Context, Value
+
+type OperationFn = Callable[[Sequence[Value]], Value]
+
+
+@dataclass(frozen=True)
+class Primitive:
+    name: str
+    arity: int
+    operation_fn: OperationFn | None
+
+    def eval(self, args: Sequence[Value], context: Context) -> Value:
+        if self.operation_fn is None:
+            return context[self]
+
+        return self.operation_fn(args)
+
+    def __post_init__(self) -> None:
+        if self.arity != 0 and self.operation_fn is None:
+            raise ValueError("Operation is required for primitive with non-zero arity")
+
+
+def Var(name: str) -> Primitive:
+    return Primitive(name=name, arity=0, operation_fn=None)
+
+
+def Const(name: str, val: Value) -> Primitive:
+    return Primitive(name=name, arity=0, operation_fn=lambda _args: val)
+
+
+def Operation(name: str, arity: int, operation_fn: OperationFn) -> Primitive:
+    return Primitive(name=name, arity=arity, operation_fn=operation_fn)