025 nested if in for

✓ Passing This code compiles and runs correctly.

Code

// TEST: Nested ~if inside ~for with outer obligation
// STATUS: IMPLEMENTED
//
// Open file before for-loop, use if inside the loop body,
// close at done. The if branches are non-repeating WITHIN
// each loop iteration, but the loop itself repeats.
//
// Key insight: The if's then/else don't create new scope boundaries
// because they run at most once per iteration. The outer obligation
// flows through the entire loop to done.

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

const condition = true;

~app.fs:open(path: "test.txt")
| opened f |>
    std.control:for(0..3)
    | each _ |>
        std.control:if(condition)
        | then |> _  // Fine - just ends this iteration
        | else |> _  // Fine - just ends this iteration
    | done |>
        app.fs:close(file: f.file)  // Close after loop completes
        | closed |> _

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