017 scope label loop

○ Planned This feature is planned but not yet implemented.

Auto-dispose for obligations in @loop branches not implemented

Code

// TEST: #loop/@loop scope behavior
// STATUS: PENDING IMPLEMENTATION
//
// When using #loop/@loop (label-based loops), the branch that leads to
// @loop creates a scope. Obligations created in that branch should be
// auto-discharged before the jump back.
//
// Here: The | next |> branch opens a file and jumps back.
// Each iteration should close the file before @loop.
//
// Expected: Compiles with open/close per iteration

~import "$app/fs"

const std = @import("std");

~event iterate { count: i32 }
| next { count: i32 }
| done {}

~proc iterate {
    if (count < 3) {
        return .{ .next = .{ .count = count + 1 } };
    } else {
        return .{ .done = .{} };
    }
}

~#loop iterate(count: 0)
| next n |>
    app.fs:open(path: "test.txt")
    | opened f |> @loop(count: n.count)  // Auto-close f before @loop
| done |> _

pub fn main() void {}

input.kz

Expected Output

Opening file
Closing file
Opening file
Closing file
Opening file
Closing file

Imported Files

// Library module: fs
// Single disposal event

const std = @import("std");

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\n", .{});
    const f = std.heap.page_allocator.create(File) catch unreachable;
    f.* = File{ .handle = 42 };
    return .{ .opened = .{ .file = f } };
}

// Close - the ONLY consumer of [!opened]
~pub event close { file: *File[!opened] }
| closed {}

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

fs.kz

Test Configuration

MUST_RUN

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