render prysm chunks

A rune program renders UI by evaluating to a chunk-noun, which rune-prysm decodes into tape::Chunks — the wire format prysm draws to wgpu, ansi, or html. rune eval shows the decoded chunks.

All commands run from rs/.

constructors

a single chunk

cargo run --bin rune -- eval 'text("hello")'

(# t) hello

several chunks in a column

cargo run --bin rune -- eval 'col(text("first"), text("second"))'

(# t) first
(# t) second

col yields one chunk per element, in order.

emitting versus returning

A chunk can be the program's value (as above) or it can be emitted as the program runs, through the emit act:

cargo run --bin rune -- eval 'emit(text("a"))'

Emitted chunks appear first, then the final value's chunks. Both feed the same prysm::dispatch. The difference matters once a program emits many chunks over time — see acts and the ward.

non-UI values

A program whose value is not a chunk-noun — plain arithmetic, say — prints as a noun instead:

cargo run --bin rune -- eval '6 * 7'

42