@spec find_node_at_offset(children(), non_neg_integer()) ::
  {children(), any_node() | nil, children(), non_neg_integer()}

Find the node at a given offset.

Returns {before_nodes, target_node, after_nodes, offset_in_node}.

Examples

iex> children = [
...>   {:text, %{text: "Hello", marks: []}, []},
...>   {:text, %{text: " world", marks: []}, []}
...> ]
iex> {before, target, after_nodes, offset_in_node} = Quillon.Transform.Split.find_node_at_offset(children, 7)
iex> before
[{:text, %{text: "Hello", marks: []}, []}]
iex> target
{:text, %{text: " world", marks: []}, []}
iex> after_nodes
[]
iex> offset_in_node
2

@spec split_at_offset(children(), non_neg_integer()) :: children()

Split text nodes at a given offset within the children list.

Returns unchanged list if offset falls on a node boundary. Preserves marks when splitting a node.

Only text nodes split. An offset landing inside a node of another type is clamped rather than split - the list comes back unchanged - because splitting such a node would need a schema the library does not have.

Examples

iex> children = [{:text, %{text: "Hello world", marks: []}, []}]
iex> Quillon.Transform.Split.split_at_offset(children, 5)
[
  {:text, %{text: "Hello", marks: []}, []},
  {:text, %{text: " world", marks: []}, []}
]

iex> children = [{:text, %{text: "Hello world", marks: [:bold]}, []}]
iex> Quillon.Transform.Split.split_at_offset(children, 5)
[
  {:text, %{text: "Hello", marks: [:bold]}, []},
  {:text, %{text: " world", marks: [:bold]}, []}
]

iex> children = [{:text, %{text: "Hello", marks: []}, []}]
iex> Quillon.Transform.Split.split_at_offset(children, 0)
[{:text, %{text: "Hello", marks: []}, []}]

iex> children = [{:text, %{text: "Hello", marks: []}, []}]
iex> Quillon.Transform.Split.split_at_offset(children, 5)
[{:text, %{text: "Hello", marks: []}, []}]

@spec split_range(children(), non_neg_integer(), non_neg_integer()) :: children()

Split text nodes at both start and end offsets for a range.

Splits at END first, then START to preserve start offset position. This is crucial for correct mark application.

Examples

iex> children = [{:text, %{text: "Hello world", marks: []}, []}]
iex> Quillon.Transform.Split.split_range(children, 2, 7)
[
  {:text, %{text: "He", marks: []}, []},
  {:text, %{text: "llo w", marks: []}, []},
  {:text, %{text: "orld", marks: []}, []}
]

iex> children = [{:text, %{text: "Hello", marks: []}, []}]
iex> Quillon.Transform.Split.split_range(children, 0, 5)
[{:text, %{text: "Hello", marks: []}, []}]