Presentation

Presentation is separate from the value an expression returns. A presenter is a terminal stage: it produces a renderable result rather than transforming the value semantically, and nothing pipes out of it.

Presenter	Result
table	rows and columns
json	structured data
graph	a graph view
markdown	document text
tree	nested structure
text	plain text
value	the value's own rendering
empty	nothing rendered

cards
| typed RelationCard
| table

A cell without a presenter

A cell that ends without a presenter uses a host default chosen by the result type. Knowledge is excluded from that default, because its views are equally valid and picking one silently would make a presentation choice look like a property of the knowledge.

Rendering belongs to the host. Printing or saving is an explicit effect, and constructing an updated Card does not itself persist a document.

graph is doing two jobs

graph appears both as the projection from knowledge to a graph and as a view of one. The projection is a function over values; the view is a presenter. They are currently the same name, and separating them — or deciding they are one thing — is unresolved. expand is traversal and stays distinct from both; see hql/semantic-search.

Open

• Presenter naming, and whether one opaque Presentation type or named subtypes.
• Whether graph is the projection or the view.
• Presenter arguments — columns for table, depth for tree — and whether a presenter may be parameterized at all.
• Conversion between presentations, and what HmdGraph is as a value.

See pipes for the execution direction and hql/knowledge for the projection this separates itself from.