The expression language

Each parameter value is a tiny arithmetic expression, compiled once when the preset loads and evaluated every frame. It is deliberately small: pure, allocation-free, and total (evaluation never panics), so it is safe to run per parameter per frame during a live show.

In this section

• Grammar
• Variables
• Constants
• Functions
• bin(x) — reaching the spectrum
• hash(x) and noise(x) — seeded randomness
• index — one binding, evaluated once per element
• [per_vertex] — one binding, evaluated once per mesh vertex
• Comparisons and branching
• Decibels
• Idioms (patterns from the curated set)
• What an expression cannot do: shape a value over time
• The [latch] table — arm on one thing, fire on another
• The [hold] table — re-sample on a musical edge, hold in between