024 if hybrid manual auto

✓ Passing This code compiles and runs correctly.

Code

// TEST: Auto-discharge fills in missing disposal in else branch
// STATUS: IMPLEMENTED
//
// When an obligation is created BEFORE an ~if, and only the then
// branch manually disposes, auto-discharge inserts cleanup at the
// else branch's terminal.
//
// Even though we use explicit binding (f), the terminal _ in else
// triggers auto-discharge which sees the unsatisfied obligation.

~import "$std/control"
~import "$app/fs"

const condition = true;

~app.fs:open(path: "test.txt")
| opened f |>
    std.control:if(condition)
    | then |>
        app.fs:close(file: f.file)
        | closed |> _
    | else |> _  // ERROR? Obligation not satisfied here!

pub fn main() void {}
input.kz

Imported Files

// Library module: fs
// Defines filesystem operations with cleanup obligations

const std = @import("std");

// File type with phantom states
const File = struct {
    handle: i32,
};

// Open a file - returns opened! state (requires cleanup)
~pub event open { path: []const u8 }
| opened { file: *File[opened!] }

~proc open {
    std.debug.print("Opening file: {s}\n", .{path});
    const allocator = std.heap.page_allocator;
    const f = allocator.create(File) catch unreachable;
    f.* = File{ .handle = 42 };
    return .{ .opened = .{ .file = f } };
}

// Close a file - CONSUMES opened! state (disposes the resource)
~pub event close { file: *File[!opened] }
| closed {}

~proc close {
    std.debug.print("Closing file\n", .{});
    return .{ .closed = .{} };
}
fs.kz