Module doc 

The document model.

A Doc is a flat list of Blocks with an indent level, not a nested tree. That is Notion’s model rather than CommonMark’s, and it is the decision the rest of this crate hangs off: editing a flat list means Enter splits, Backspace merges, and Tab indents — all list operations. On a nested tree “the previous block” is a traversal and every edit is a restructure.

The trade is that arbitrarily nested CommonMark does not survive a round trip: a list inside a quote inside a list flattens. Notion has the same limitation. What is guaranteed is [crate::serialize]’s fixed point — parse, serialize, parse again, and the document is unchanged — so an edit/save cycle never drifts.

Structs

Block

One block, and how deeply it is nested.

Doc

A markdown document: blocks in document order.

MarkSpan

Text

Inline content: a string, plus marks over byte ranges of it.

Enums

Align

GFM column alignment.

BlockKind

The block vocabulary. Closed by design — a consumer that needs a block of its own is a reason to widen this enum rather than to grow an extension system.

Form

How a Mark::Mention was written down, which is also how it paints.

Mark

Part

Which of a block’s texts a caret sits in.

QuoteKind

A GFM alert’s kind — the [!NOTE] marker a blockquote opens with.