082 ecology custom transform

// ECOLOGY TEST: User-defined [transform] events should work like stdlib ones
//
// ISSUE: The transform mechanism shouldn't require magic. A user should be
// able to define their own [transform] event and have it work exactly like
// ~for, ~if, ~capture from $std/control.
//
// This test captures the intention that transforms are NOT special-cased
// for stdlib - they're a general mechanism.

~import "$std/io"

// User-defined transform event - should work just like stdlib transforms
~[keyword|comptime|transform]
pub event repeat {
    times: i32,
    invocation: *const Invocation,
    item: *const Item,
    program: *const Program,
}
| done { * }

// The transform proc - generates a simple loop
~proc repeat {
    // For now, just return unchanged - the INTENTION is that this should
    // be able to generate code like ~for does
    return .{ .done = .{ .program = program } };
}

// Use our custom transform
~repeat(3)
| done |> std.io:println(text: "Custom transform executed")