pub const STREAM_DEPTH: u32 = 32;Expand description
The derivation depth an endless figure’s stream walks: the grammar is expanded this many times, lazily, and the stream is its leaves in order.
Thirty-two levels of a rule that only doubles its draw steps buy 2^32,
about 4.3 billion of them, which is 6.8 years of growth at 20 steps a
second; a rule that grows faster buys more. The stream’s stack is one frame
per level, so the depth costs 33 frames of memory and nothing per symbol.