# json.cpu.stage2

> A module of json_mlake's API.

## Functions

### `parse_two_pass_tape`

```mojo
def parse_two_pass_tape[force_scalar: Bool = False](var input: String) -> Document
```

End-to-end stage 1 + stage 2 parse that emits a `Document`.

Parameters:

- `force_scalar`: When False (default), use the SIMD stage 1
    implementation (`stage1.parse_structural_simd`); on the
    benchmark corpora SIMD is ~1.2x faster than the scalar
    walker. When True, use the scalar oracle -- useful for
    differential testing and for inputs small enough that the
    SIMD chunk loop never runs (n < 32). Both produce identical
    output (enforced by `tests/test_stage1_equivalence.mojo`);
    this is purely a performance switch.

Args:

- `input`: JSON input. The returned `Document` owns this string,
    so its bytes can back zero-copy string slices on the tape.

### `parse_into_document`

```mojo
def parse_into_document(var input: String, index: StructuralIndex) -> Document
```

Build a `Document` (tape + side pools) by walking the structural index over `input`. The returned document owns `input`.

Args:

- `input`: Original JSON bytes.
- `index`: Output of stage 1. Borrowed immutably -- `positions` is
    read in place, no copy on entry.