# Building documents

## From scratch

```python
from tomlrt import Document, dumps

doc = Document()
doc["title"] = "example"
print(dumps(doc))
```

```toml
title = "example"
```

## From a `dict`

Pass a mapping to `Document` to populate it recursively:

```python
from tomlrt import Document, dumps

data = {
    "project": {
        "name": "demo",
        "version": "0.1.0",
        "dependencies": ["requests>=2"],
    },
    "tool": {"ruff": {"line-length": 88}},
}

doc = Document(data)
print(dumps(doc))
```

```toml
[project]
name = "demo"
version = "0.1.0"
dependencies = ["requests>=2"]

[tool.ruff]
line-length = 88
```

Nested mappings become `[section]` blocks (not inline tables); lists of mappings become `[[array.of.tables]]` blocks; everything else is an ordinary key-value assignment.

`Document(data)` copies its input; changing `data` afterward does not affect the document.

## Choosing tables and arrays

When assigning individual values, a plain `dict` installs as an inline table; a plain `list` installs as an inline array. Use `Table.section()` or `Table.inline()` to choose the table form, and `AoT` or `Array` to choose the array form:

```python
from tomlrt import AoT, Array, Document, Table, dumps

doc = Document()
doc["tool"] = Table.section({"version": 1})
doc["xy"] = Table.inline({"x": 1, "y": 2})
doc["pkgs"] = AoT([{"a": 1}, {"b": 2}])
doc["tags"] = Array(["a", "b"], multiline=True)
print(dumps(doc))
```

```toml
xy = { x = 1, y = 2 }
tags = [
    "a",
    "b",
]

[tool]
version = 1

[[pkgs]]
a = 1

[[pkgs]]
b = 2
```