ripple

Incremental computation library for MoonBit, inspired by Rust's salsa.

Changes ripple through the dependency graph, recomputing only what's necessary.

• Automatic dependency tracking - Dependencies recorded during query execution
• Minimal recomputation - Only changed inputs trigger recomputation
• Deep verification - Cached results validated against dependency graph
• Cycle detection - CycleQuery handles recursive dependencies with fallback values
• Value interning - Deduplicate values with stable IDs
• Accumulator - Collect diagnostics/warnings during computation
• Durability levels - Skip verification for rarely-changed inputs

moon add mizchi/ripple

let db = @ripple.Database::new()
let rt = db.runtime()

// Define inputs
let files : @ripple.Input[String, String] = db.input()
files.register(rt)

// Define memoized queries
let parse : @ripple.Query[String, Array[String]] = db.query(fn(rt, path) {
  match files.get(rt, path) {
    Some(content) => extract_imports(content)
    None => []
  }
})
parse.register(rt)

// Set inputs and run queries
files.set(rt, "main.mbt", "import lib") |> ignore
let imports = parse.fetch(rt, "main.mbt")  // ["lib"]

// Change input - only affected queries recompute
files.set(rt, "main.mbt", "import lib, utils") |> ignore
let imports2 = parse.fetch(rt, "main.mbt")  // ["lib", "utils"] - recomputed

See src/usage.mbt.md for detailed usage examples with runnable tests.

• Incremental compilers - Re-parse/type-check only changed files
• Build systems - Recompile only affected targets
• IDE features - Fast re-analysis on code changes
• Reactive systems - Efficient derived state updates

MIT