cagire-forth

Stack-based Forth VM for the Cagire sequencer. Tokenizes, compiles, and executes step scripts to produce audio and MIDI commands.

Modules

Module	Description
`vm`	Interpreter loop, `Forth::evaluate()` entry point
`compiler`	Tokenization (with source spans) and single-pass compilation to ops
`ops`	`Op` enum (~90 variants)
`types`	`Value`, `StepContext`, shared state types
`words/`	Built-in word definitions: `core`, `sound`, `music`, `midi`, `effects`, `sequencing`, `compile`
`theory/`	Music theory lookups: `scales` (~200 patterns), `chords` (interval arrays)

Forth — VM instance, holds stacks and compilation state
Value — Stack value (int, float, string, list, quotation, ...)
StepContext — Per-step evaluation context (step index, tempo, variables, ...)
Op — Compiled operation; nondeterministic variants carry Option<SourceSpan> for tracing
ExecutionTrace — Records executed/selected spans and resolved values during evaluation