# wastrel milestone: full hoot support, with generational gc as a treat

DevFeed: [wastrel milestone: full hoot support, with generational gc as a treat](<https://devfeed.tech/articles/wastrel-milestone-full-hoot-support-with-generational-gc-as-a-treat-35036.md>)

Original publisher: [Read original article](<https://wingolog.org/archives/2026/04/09/wastrel-milestone-full-hoot-support-with-generational-gc-as-a-treat>)

Author: Andy Wingo

Published: 2026-04-09T13:48:04Z

Content type: article

Language: en

Sources: [wingolog](<https://devfeed.tech/sources/wingolog.md>)

Topics: [WebAssembly](<https://devfeed.tech/topics/web-assembly.md>), [scheme](<https://devfeed.tech/topics/scheme.md>), [toolchain](<https://devfeed.tech/topics/toolchain.md>), [gcc](<https://devfeed.tech/topics/gcc.md>)

Tags: [binaries](<https://devfeed.tech/tags/binaries.md>), [garbage-collection](<https://devfeed.tech/tags/garbage-collection.md>), [gc](<https://devfeed.tech/tags/gc.md>), [gcc](<https://devfeed.tech/tags/gcc.md>), [hoot](<https://devfeed.tech/tags/hoot.md>), [optimization](<https://devfeed.tech/tags/optimization.md>), [repl](<https://devfeed.tech/tags/repl.md>), [scheme](<https://devfeed.tech/tags/scheme.md>), [spidermonkey](<https://devfeed.tech/tags/spidermonkey.md>), [toolchain](<https://devfeed.tech/tags/toolchain.md>), [treats](<https://devfeed.tech/tags/treats.md>), [v8](<https://devfeed.tech/tags/v8.md>), [wasm](<https://devfeed.tech/tags/wasm.md>), [wastrel](<https://devfeed.tech/tags/wastrel.md>), [web](<https://devfeed.tech/tags/web.md>), [webassembly](<https://devfeed.tech/tags/webassembly.md>)

## AI overview

The article describes a Wastrel milestone: compiling WebAssembly files produced by the Hoot Scheme toolchain into native binaries, including a console-based read-eval-print loop. It covers the build process, runtime modules, binary size, dependencies, and initial performance observations.

## Source excerpt

Hear ye, hear ye: Wastrel and Hoot means REPL! Which is to say, Wastrel can now make native binaries out of WebAssembly files as produced by the Hoot Scheme toolchain, up to and including a full read-eval-print loop. Like the REPL on the Hoot web page, but instead of requiring a browser, you can just run it on your console. Amazing stuff! try it at home First, we need the latest Hoot. Build it from source, then compile a simple REPL: echo '(import (hoot repl)) (spawn-repl)' > repl.scm ./pre-inst-env hoot compile -fruntime-modules -o repl.wasm repl.scm This takes about a minute. The resulting wasm file has a pretty full standard library including a full macro expander and evaluator. Normally Hoot would do some aggressive tree-shaking to discard any definitions not used by the program, but with a REPL we don't know what we might need. So, we pass -fruntime-modules to instruct Hoot to record all modules and their bindings in a central registry, so they can be looked up at run-time. This results in a 6.6 MB Wasm file; with tree-shaking we would have been at 1.2 MB. Next, build Wastrel from source, and compile our new repl.wasm: wastrel compile -o repl repl.wasm This takes about 5 minutes on my machine: about 3 minutes to generate all the C, about 6.6MLOC all in all, split into a couple hundred files of about 30KLOC each, and then 2 minutes to compile with GCC and link-time optimization (parallelised over 32 cores in my case). I have some ideas to golf the first part down a bit, but the the GCC side will resist improvements. Finally, the moment of truth: $ ./repl Hoot 0.8.0 Enter `,help' for help. (hoot user)> "hello, world!" => "hello, world!" (hoot user)> statics When I first got the REPL working last week, I gasped out loud: it's alive, it's alive!!! Now that some days have passed, I am finally able to look a bit more dispassionately at where we're at. Firstly, let's look at the compiled binary itself. By default, Wastrel passes the -g flag to GCC, which results in bi