# json.cpu.stage1_scalar

> A module of json_mlake's API.

## Structs

### `StructuralIndex`

```mojo
struct StructuralIndex
```

Sorted list of structural-character offsets in the input.

`positions[i]` is the byte offset of the i-th structural character.
The list is strictly increasing.

Stage 2 traverses the positions in order; each position points at a
char in `{ } [ ] : , "` outside of any string literal (with both
opening and closing quotes recorded).

Implements: `Copyable`, `Movable`

Fields:

- `positions: List[UInt32]`

#### `__init__`

```mojo
def __init__(out self, capacity: Int = Int(0))
```

#### `copy`

```mojo
def copy(self) -> Self
```

#### `size`

```mojo
def size(self) -> Int
```

## Functions

### `parse_structural_scalar`

```mojo
def parse_structural_scalar(input: String) -> StructuralIndex
```

Build a structural index by walking the input byte-by-byte.

Always succeeds: even malformed JSON produces *some* index, since
stage 1 only tracks string state. Errors surface in stage 2 when
the index is walked.

Args:

- `input`: Raw JSON bytes.