{
  "schema": "ailang/v0",
  "name": "str_field_in_adt_heap",
  "imports": [],
  "defs": [
    {
      "kind": "type",
      "name": "Boxed",
      "vars": [],
      "doc": "Iter hs.4 fixture: single-cell ADT around a Str field. Used to pin the drop discipline for ADTs that carry a heap-Str payload — both the ADT cell and the heap-Str inside it must round-trip through the RC walk.",
      "ctors": [
        {
          "name": "Box",
          "fields": [{ "k": "con", "name": "Str" }]
        }
      ]
    },
    {
      "kind": "fn",
      "name": "main",
      "type": {
        "k": "fn",
        "params": [],
        "ret": { "k": "con", "name": "Unit" },
        "effects": ["IO"]
      },
      "params": [],
      "doc": "Iter hs.4: pin that `field_drop_call` for `Str` correctly dispatches to `ailang_rc_dec` when the Str payload is heap-Str. Construct `Box(int_to_str(42))`, bind, pattern-match to read the Str, print it. Under --alloc=rc with AILANG_RC_STATS=1: allocs >= 2 (ADT cell + heap-Str slab), allocs == frees, live == 0. drop.rs's Str-arm comment names the codegen-level elision that protects static-Str from this same path; here the Str is heap-allocated so rc_dec is the right (and only) consumer.",
      "body": {
        "t": "let",
        "name": "b",
        "value": {
          "t": "ctor",
          "type": "Boxed",
          "ctor": "Box",
          "args": [
            {
              "t": "app",
              "fn": { "t": "var", "name": "int_to_str" },
              "args": [{ "t": "lit", "lit": { "kind": "int", "value": 42 } }]
            }
          ]
        },
        "body": {
          "t": "match",
          "scrutinee": { "t": "var", "name": "b" },
          "arms": [
            {
              "pat": {
                "p": "ctor",
                "ctor": "Box",
                "fields": [{ "p": "var", "name": "s" }]
              },
              "body": {
                "t": "do",
                "op": "io/print_str",
                "args": [{ "t": "var", "name": "s" }]
              }
            }
          ]
        }
      }
    }
  ]
}