Glossary

Terms used across the manual, with one or two sentences each.

Audio. Signal kind for sound. Float samples in roughly [-1, +1] produced at the host’s sample rate.

Cable. A directed connection from one module’s output port to one module’s input port. Carries one signal stream of one kind.

CLAP plugin. The plugin packaging that lets a DAW host load Patches as an instrument or audio effect. Built from patches-clap, shipped as a single .dylib / .so / .dll bundle. Distinct from native plugin — see below.

Control voltage (CV). Signal kind for modulation and pitch. Pitch follows the V/oct convention: one unit per octave.

CV. See Control voltage.

DSL. The text format Patches files are written in (.patches). Specified in patches-dsl/src/grammar.pest; described in DSL basics and the DSL reference.

Edit-reload cycle. The development loop where saving a .patches file triggers an in-place engine rebuild while audio keeps playing. Covered in The edit-reload cycle.

Engine. The real-time audio component. Owns the execution plan, the module instances, and the cable pool. Sources: patches-core, patches-engine.

Execution plan. The flat, ordered list of module slots and buffer assignments the audio thread runs. Built by the planner from a ModuleGraph.

Fan-in. Multiple cables converging on one input. Not directly allowed — each input takes one cable. Combine signals through a mixer module.

Fan-out. One output driving multiple inputs. Free: draw as many cables from an output as needed, no splitter required.

FlatPatch. The intermediate representation produced by the DSL expander after template inlining and parameter substitution. A flat list of module declarations and connections — the input the interpreter validates.

Fusion. Planner optimisation that routes cross-SCC cables in acyclic (feedback-free) regions through the scratch pool region so consumers read producers’ current-tick output instead of going through the one-sample cable delay. Cycle-bearing cables stay in the cycle region and keep the one-sample delay (which makes feedback well-defined). Removes lag from long signal chains while preserving feedback-loop semantics.

Gate. Signal kind held 1.0 while a note is active, 0.0 when released. Drives an envelope’s hold-and-release behaviour.

Global config. Host-scoped persisted settings (currently: bundle directory list). Stored in a cross-platform settings.toml. Distinct from per-patch sidecar state.

Hot-reload. Same as edit-reload — the engine swaps in a new graph without stopping audio.

LSP. Language server (patches-lsp) backing the VS Code extension’s diagnostics, hover, completions, and SVG rendering. See LSP architecture.

Mono. A cable that carries one sample per audio tick.

Module. A unit of computation with a fixed set of named input and output ports. Examples: Osc, PolyAdsr, StereoMixer, AudioOut. Implementations live in patches-modules or in externally-built native plugin bundles.

Module graph. The validated graph of module instances and typed cables produced by the interpreter. Input to the planner.

Module type. The class of a module instance. Defines the instance’s ports and parameters. An instance has a name (chosen in the patch) and a type (chosen from the registry): module osc : Osc declares an instance named osc of type Osc.

Native plugin. A module bundle built as a separate cdylib and loaded at host startup via the Native plugin ABI. Distinct from CLAP plugin: native plugins add module types to Patches; the CLAP plugin embeds Patches into a DAW.

Patch. A complete .patches file: optional templates, songs, patterns, host controls, then exactly one patch { ... } block declaring modules and their connections.

Per-patch sidecar. Persisted state attached to a specific patch file. In the player, written next to the .patches file as <name>.patches.state (or under $XDG_STATE_HOME); in the CLAP plugin, written via the host’s CLAP-state mechanism. Patch knobs, monitor view toggles. Distinct from global config.

Plan. Shorthand for execution plan.

Planner. The component that turns a ModuleGraph into an ExecutionPlan, reusing module instances across reloads by name/type match. Lives in patches-planner.

Poly. A cable that carries one sample per voice per audio tick. The voice pool is 16 wide in every shipping host.

Polyphony. The ability to play multiple notes simultaneously, each on its own voice slot. Driven by PolyMidiToCv (or a similar poly source) into a poly module chain.

Port. A named input or output on a module. Each port has a kind (mono / poly / stereo) and, for mono and poly, a layout (audio / trigger / transport / midi) that connection-time validation checks.

REPL. The interactive loop the edit-reload cycle creates for patch authoring: save, listen, save again. Patches’ development workflow is REPL-shaped, not compile-run-listen-shaped.

SCC. Strongly connected component of the module graph — maximal subgraph in which every module reaches every other module. Cycle-bearing SCCs retain the one-sample cable delay; acyclic SCCs are fused.

Sidecar. See per-patch sidecar.

Signal kind. The type of signal a port carries: audio, CV, gate, trigger, or stereo. The planner uses kinds to validate connections at compile time. See Signal kinds and cable rules.

Stereo. Signal kind carrying (L, R) audio samples on one cable. A symmetric stereo module uses a single stereo port rather than paired _left/_right mono ports.

Template. A named, parameterised subgraph in a .patches file. Expanded at compile time into concrete module instances. Templates are a DSL abstraction, not a runtime construct. See Templates and abstraction.

Trigger. Signal kind: sub-sample-accurate event marker. On each sample a trigger cable carries 0.0 for “no event” or a value in (0.0, 1.0] giving the event’s fractional position within the sample (used by oscillator hard-sync, BLEP correction, etc.). Tells an envelope when to restart from its attack phase, regardless of whether the gate was already high.

V/oct. The pitch encoding convention: one unit = one octave; one semitone = 1/12 unit. Used by oscillator voct inputs and by the V/oct CV emitted by MIDI-to-CV modules.

Voice. One slot of a poly cable. A PolyAdsr or PolyOsc runs 16 voices in parallel; voice allocation is handled by PolyMidiToCv (or a sequencer with multiple voice outputs).

Voice allocation. Mapping incoming MIDI notes onto voice slots. PolyMidiToCv uses LIFO stealing: when all voices are busy, the most-recently-allocated voice is reused for the next note.

Webview GUI. The CLAP plugin’s UI, an embedded wry webview rendering a small JS app. The engine and controller live in Rust; the webview is a thin shell over the controller’s GuiSnapshot / Intent types.