steverichey · May 4, 2020 15:22 · May 4, 2020
diff --git a/LittleTyper.swift b/LittleTyper.swift
@@ -0,0 +1,39 @@
+import Cocoa
+import Foundation
+
+protocol AtomType {}
+struct Atom: AtomType {}
+
+func == <Atom1, Atom2> (lhs: Atom1, rhs: Atom2) -> Bool where Atom1: AtomType, Atom2: AtomType {
+    return type(of: lhs) == type(of: rhs) // maybe
+}
+
+func == (lhs: (Atom, Atom), rhs: (Atom, Atom)) -> Bool {
+    return true // ??
+}
+
+func cons<CarType, CdrType>(_ car: CarType, _ cdr: CdrType) -> (CarType, CdrType) {
+    return (car, cdr)
+}
+
+func car<CarType, CdrType>(_ pair: (CarType, CdrType)) -> CarType {
+    return pair.0
+}
+
+func cdr<CarType, CdrType>(_ pair: (CarType, CdrType)) -> CdrType {
+    return pair.1
+}
+
+let ratatouille = Atom()
+let garlic = Atom()
+let meal = cons(ratatouille, garlic)
+
+let tomato = Atom()
+let egg = Atom()
+let omelette = cons(tomato, egg)
+
+print(ratatouille == garlic)
+print(meal == meal)
+print(ratatouille == car(meal))
+print(garlic == cdr(meal))
+print(tomato == garlic)