# context

URL: /patitas/api/linting/context/
Section: linting
Description: LintContext — the single immutable argument passed to every lint rule.

A `LintContext` carries BOTH the parsed `Document`
AND the raw source string, plus two derived values computed eagerly at
construction: the source split into lines and the full document-order sequence
of AST nodes. AST-oriented rules read ``ctx.headings()`` /
``ctx.nodes_of_type(...)``; line-oriented rules read ``ctx.lines``.

Thread Safety:
    ``LintContext`` is a frozen, slotted dataclass. Its derived state
    (``_lines`` and ``_nodes``) is computed once in ``__post_init__`` via
    ``object.__setattr__`` BEFORE the context is ever shared, so the instance
    is fully immutable and race-free thereafter. Safe to share across threads
    within a run.

---

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Module

#
`linting.context`

LintContext — the single immutable argument passed to every lint rule.

A`LintContext` carries BOTH the parsed `Document`
AND the raw source string, plus two derived values computed eagerly at
construction: the source split into lines and the full document-order sequence
of AST nodes. AST-oriented rules read`ctx.headings()`/
`ctx.nodes_of_type(...)`; line-oriented rules read `ctx.lines`.

Thread Safety:

```
``LintContext`` is a frozen, slotted dataclass. Its derived state
(``_lines`` and ``_nodes``) is computed once in ``__post_init__`` via
``object.__setattr__`` BEFORE the context is ever shared, so the instance
is fully immutable and race-free thereafter. Safe to share across threads
within a run.
```

2Classes

## Classes

`_NodeCollector`

2

▼

Collect every node in document order via a single AST walk.

Instantiated fresh per `LintContext` c…

Bases:

`BaseVisitor (/patitas/api/visitor/#BaseVisitor)[None]`

Collect every node in document order via a single AST walk.

Instantiated fresh per `LintContext` (/patitas/api/linting/context/#LintContext) construction (never shared),
honoring the `BaseVisitor` (/patitas/api/visitor/#BaseVisitor) per-call contract. Because
`BaseVisitor.visit` (/patitas/api/visitor/#BaseVisitor) dispatches then walks children, `visit_default`is
invoked for every node in document order.

#### Methods

`visit_default`

1

▼

Append every visited node (catch-all for all node types).

`def visit_default(self, node: Node) -> None`

##### Parameters

Name
Type
Description

`node`
`—`

Internal Methods
1

▼

`__init__`

0

▼

Initialize with an empty accumulator.

`def __init__(self) -> None`

`LintContext`

9

▼

Immutable context handed to each rule's ``check`` method.

Immutable context handed to each rule's`check`method.

#### Attributes

Name
Type
Description

`document`

`Document (/patitas/api/nodes/#Document)`

The parsed AST root.

`source`

`str`

The raw Markdown source (empty string if unavailable).

`source_file`

`str | None`

Optional source file path, propagated into diagnostics.

`_lines`

`tuple[str, ...]`

—

`_nodes`

`tuple[Node (/patitas/api/nodes/#Node), ...]`

—

#### Methods

`lines`

0

`tuple[str, ...]`

▼

Source split on ``"\n"`` (1-indexed line N is ``lines[N - 1]``).

property

`def lines(self) -> tuple[str, ...]`

##### Returns

`tuple[str, ...]`

`nodes_of_type`

1

`tuple[N, ...]`

▼

Return all nodes of ``node_type`` in document order.

Filters the prebuilt docu…

`def nodes_of_type(self, node_type: type[N]) -> tuple[N, ...]`

Return all nodes of`node_type`in document order.

Filters the prebuilt document-order node sequence, so rules never spin
up their own AST walk.

##### Parameters

Name
Type
Description

`node_type`
`—`

The node class to filter for (e.g.`Link`).

##### Returns

`tuple[N, ...]`

A tuple of matching nodes in document order.

`headings`

0

`tuple[Heading (/patitas/api/nodes/#Heading), ...]`

▼

Return all `Heading` nodes in document order.

Sugar for ``nodes_of_type(Headin…

`def headings(self) -> tuple[Heading, ...]`

Return all `Heading` (/patitas/api/nodes/#Heading) nodes in document order.

Sugar for`nodes_of_type(Heading)`.

##### Returns

`tuple[Heading (/patitas/api/nodes/#Heading), ...]`

A tuple of headings in document order.

Internal Methods
1

▼

`__post_init__`

0

▼

Eagerly compute derived line and node sequences.

Uses ``object.__setattr__`` (…

`def __post_init__(self) -> None`

Eagerly compute derived line and node sequences.

Uses`object.__setattr__`(the sanctioned escape hatch for frozen
dataclasses) to populate the private slots. Splitting on`"\n"`—
NOT`str.splitlines()`— keeps synthesized line numbers in lockstep
with the parser, which also counts`"\n"` boundaries (`splitlines`
over-splits on form-feed/vertical-tab/Unicode separators).