# Command line

The reference below is taken from the program itself. `interpres-decode` is the
toml-test harness adapter, not a general-purpose tool: it takes no flags and no
arguments, reads one TOML document from stdin, and writes the toml-test
tagged-JSON form to stdout.

## Synopsis

```sh
interpres-decode < document.toml
```

Build it with `just build`, which compiles it into `bin/interpres-decode`, or
run it straight from the module directory with `just run`.

## Exit codes

| Code | Meaning |
|---|---|
| `0` | the document parsed, tagged JSON written to stdout |
| `1` | parse error, the document is malformed; the message goes to stderr |
| `2` | reading stdin failed, or a value has no tagged representation |

## Wire format

Tables become JSON objects, arrays become JSON arrays, and every scalar is
wrapped in an object with a `type` and a `value`:

```json
{
  "title": {"type": "string", "value": "hello"},
  "port": {"type": "integer", "value": "9090"},
  "enabled": {"type": "bool", "value": "true"},
  "ratio": {"type": "float", "value": "3.14"}
}
```

| TOML value | Tag | Rendering |
|---|---|---|
| string | `string` | the string verbatim |
| integer | `integer` | decimal |
| float | `float` | decimal, or `inf`, `-inf`, `nan` |
| boolean | `bool` | `true` or `false` |
| offset date-time | `datetime` | RFC 3339 with nanoseconds |
| local date-time | `datetime-local` | `1979-05-27T07:32:00` |
| local date | `date-local` | `1979-05-27` |
| local time | `time-local` | `07:32:00.999999` |

## Examples

Echo a small document through the adapter:

```sh
echo 'title = "hello"
[server]
host = "127.0.0.1"
port = 9090
' | ./bin/interpres-decode
```

The output is the equivalent value tree as one JSON object. Run the official
compliance suite against the binary:

```sh
just toml-test
```

That recipe needs the `toml-test` binary on `PATH`, installed with
`go install github.com/toml-lang/toml-test/cmd/toml-test@v1.6.0`. The full
reference for the library itself is [API.md](API.md).