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Jun 2025 (v0.6.1)

Mochi v0.6.1 adds file I/O for datasets, a minimal foreign function interface and optional DuckDB execution for queries.

Load and Save​

Use load to read CSV or JSONL data into a typed list and save to export results. Paths are optional for piping via standard input and output.

let people = load "people.csv" as Person
let adults = from p in people where p.age >= 18 select p
save adults to "adults.jsonl" with { format: "jsonl" }

Foreign Function Interface​

The new runtime/ffi package exposes Go, TypeScript and Python runtimes. Programs declare extern fun and extern object bindings which resolve to registered host implementations.

DuckDB Query Engine​

Dataset queries can execute through DuckDB for larger data sets. Builds without CGO fall back to the in-memory engine.

Other Changes​

  • --wasm-toolchain flag selects the Go or TinyGo compiler
  • Improved type inference across compilers
  • Fixed DuckDB optional build and updated golden tests