dummyscheme

DummyScheme is a lightweight, embeddable Scheme interpreter built on a register-based bytecode virtual machine — now available as a mobile REPL. Type Scheme expressions and get answers instantly. Everything runs locally on your device: no account, no ads, no permissions, no internet required.

Use it anywhere — for SICP exercises, quick list-processing experiments, or exploring functional programming. Multi-line forms, command history and clear VM diagnostics make it feel like a real terminal session. The Android app is powered by the exact same portable C++ VM that runs on desktop and in the browser (via WebAssembly), so behavior is consistent across platforms.

- Full Scheme interpreter on a register-based bytecode VM (R5RS)

- Tail-call optimization — recursion without stack growth

- First-class continuations (call/cc)

- Bignum number tower — exact arithmetic, integers never overflow

- Hygienic macros (syntax-rules)

- Number tower, bignum is supported too

- Line-level debug info with source location tracking

- Lua-like embeddability and portability: platform-independent, easy to integrate into C/C++ host applications

- Full tests passed with r4rstest (pass SCHEME_STD_R4RS=1) and r5rs-tests

- dynamic-wind support, netsted with call/cc, jump to(out) dynamic-wind's thunk/body, allow to jump out dynamic-wind's before and after, but jumping into is not forbidden

- values+call-with-values

- hash-table (inspired by lua)

```

(make-hash-table)

(hash-table-ref table key)

(hash-table-set! table key val)

(hash-table-for-each (lambda (key val) xxx) table)

```