136 effect arms never nest effects

✓ Passing Passing: the compiler rejects this program as expected.

Code

// "Never nest `!`": an indented `!` under an effect branch is not a resume
// arm and not legal anywhere — effect composition lives in the flat `|` arm
// list, never in nested effects. Sibling of the accept pins 210_092/093.
~pub tor request { payload: i32 }
! ask i32
    ! nested i32
    | timeout
| done i32

~proc request|zig {
    const r = ask(payload);
    return .{ .done = r };
}

input.kz

Actual compiler output

error[PARSE003]: effect branches never nest - composition lives in the '|' resume arms
  --> tests/regression/200_COMPILER_FEATURES/210_PARSER/210_136_effect_arms_never_nest_effects/input.kz:6:1
    |
  6 |     ! nested i32
    | ^

Frontend must reject with:

CONTAINS effect branches never nest

Test Configuration

MUST_ERROR

← 135 effect arms exclusive with resume type 137 effect unit payload spelled by omission →