iter 23.3.3: prelude — class Ord a extends Eq + Ord Int/Bool/Str instances

2026-05-10 23:13:02 +02:00
parent 119632812d
commit 12d9130567
2 changed files with 139 additions and 0 deletions
@@ -118,6 +118,106 @@
          }
        }
      ]
+    },
+    {
+      "kind": "class",
+      "name": "Ord",
+      "param": "a",
+      "superclass": { "class": "Eq", "type": "a" },
+      "doc": "Total ordering. Ships in milestone 23 alongside Eq. `compare x y` returns LT, EQ, or GT (the three-ctor Ordering ADT also in the prelude). Decision 11's single-superclass closure requires `instance Eq T` for every `instance Ord T` — the three Ord instances below pair with the three Eq instances shipped in iter 23.2.3.",
+      "methods": [
+        {
+          "name": "compare",
+          "type": {
+            "k": "fn",
+            "params": [
+              { "k": "var", "name": "a" },
+              { "k": "var", "name": "a" }
+            ],
+            "param_modes": ["borrow", "borrow"],
+            "ret": { "k": "con", "name": "Ordering" },
+            "effects": []
+          }
+        }
+      ]
+    },
+    {
+      "kind": "instance",
+      "class": "Ord",
+      "type": { "k": "con", "name": "Int" },
+      "doc": "Ord Int. The lambda body shape is a placeholder for round-trip stability; the codegen intercept `try_emit_primitive_instance_body::\"compare__Int\"` emits a three-way `icmp slt` / `icmp eq` branch ladder constructing LT / EQ / GT.",
+      "methods": [
+        {
+          "name": "compare",
+          "body": {
+            "t": "lam",
+            "params": ["x", "y"],
+            "paramTypes": [
+              { "k": "var", "name": "a" },
+              { "k": "var", "name": "a" }
+            ],
+            "retType": { "k": "con", "name": "Ordering" },
+            "body": {
+              "t": "ctor",
+              "type": "Ordering",
+              "ctor": "EQ",
+              "args": []
+            }
+          }
+        }
+      ]
+    },
+    {
+      "kind": "instance",
+      "class": "Ord",
+      "type": { "k": "con", "name": "Bool" },
+      "doc": "Ord Bool. Body lowered via `try_emit_primitive_instance_body::\"compare__Bool\"` — `icmp ult i1` LT-test, `icmp eq i1` EQ-test, GT default.",
+      "methods": [
+        {
+          "name": "compare",
+          "body": {
+            "t": "lam",
+            "params": ["x", "y"],
+            "paramTypes": [
+              { "k": "var", "name": "a" },
+              { "k": "var", "name": "a" }
+            ],
+            "retType": { "k": "con", "name": "Ordering" },
+            "body": {
+              "t": "ctor",
+              "type": "Ordering",
+              "ctor": "EQ",
+              "args": []
+            }
+          }
+        }
+      ]
+    },
+    {
+      "kind": "instance",
+      "class": "Ord",
+      "type": { "k": "con", "name": "Str" },
+      "doc": "Ord Str. Body lowered via `try_emit_primitive_instance_body::\"compare__Str\"` — `call i32 @ail_str_compare(ptr, ptr)` then branch on slt-0 / eq-0 against the normalised {-1, 0, +1} return.",
+      "methods": [
+        {
+          "name": "compare",
+          "body": {
+            "t": "lam",
+            "params": ["x", "y"],
+            "paramTypes": [
+              { "k": "var", "name": "a" },
+              { "k": "var", "name": "a" }
+            ],
+            "retType": { "k": "con", "name": "Ordering" },
+            "body": {
+              "t": "ctor",
+              "type": "Ordering",
+              "ctor": "EQ",
+              "args": []
+            }
+          }
+        }
+      ]
    }
  ]
 }