How to make a fast dynamic language interpreter

#1

Post by pizlonator » Tue, Apr 21, 2026, 12:48 AM UTC

How to make a fast dynamic language interpreter
zef-lang.dev

Re: How to make a fast dynamic language interpreter

#2

Post by grg0 » Tue, Apr 21, 2026, 1:56 AM UTC

Interesting, thanks for sharing. It is a topic I'd like to explore in detail at some point.

I also like how, according to Github, the repo is 99.7% HTML and 0.3% C++. A testament to the interpreter's size, I guess?

Re: How to make a fast dynamic language interpreter

#3

Post by pizlonator » Tue, Apr 21, 2026, 1:59 AM UTC

grg0 wrote: post #2

Interesting, thanks for sharing. It is a topic I'd like to explore in detail at some point. I also like how, according to Github, the repo is 99.7% HTML and 0.3% C++. A testament to the interpreter's size, I guess?

I committed the statically generated site, which is wastefully large because how I generate the code browsers

But yeah the interpreter is very small

Re: How to make a fast dynamic language interpreter

#4

Post by Futurmix » Tue, Apr 21, 2026, 2:27 AM UTC

[flagged]

Re: How to make a fast dynamic language interpreter

#5

Post by boulos » Tue, Apr 21, 2026, 3:17 AM UTC

How's your experience with Fil-C been? Is it materially useful to you in practice?

Re: How to make a fast dynamic language interpreter

#6

Post by pizlonator » Tue, Apr 21, 2026, 3:21 AM UTC

boulos wrote: post #5

How's your experience with Fil-C been? Is it materially useful to you in practice?

I’m biased since I’m the Fil.

It was materially useful in this project.

- Caught multiple memory safety issues in a nice deterministic way, so designing the object model was easier than it would have been otherwise.

- C++ with accurate GC is a really great programming model. I feel like it speeds me up by 1.5x relative to normal C++, and maybe like 1.2x relative to other GC’d languages (because C++’s APIs are so rich and the lambdas/templates and class system is so mature).

But I’m biased in multiple ways

- I made Fil-C++

- I’ve been programming in C++ for like 35ish years now

Re: How to make a fast dynamic language interpreter

#7

Post by tiffanyh » Tue, Apr 21, 2026, 3:41 AM UTC

I see Lua was included, wish LuaJIT was as well.

Re: How to make a fast dynamic language interpreter

#8

Post by pizlonator » Tue, Apr 21, 2026, 3:43 AM UTC

tiffanyh wrote: post #7

I see Lua was included, wish LuaJIT was as well.

I bet LuaJIT crushes Zef! Or rather, I would hope that it does, given how much more engineering went into it

There are many runtimes that I could have included but didn’t.

Also, it’s quite impressive how much faster PUC Lua is than QuickJS and Python

Re: How to make a fast dynamic language interpreter

#9

Post by zephen » Tue, Apr 21, 2026, 4:19 AM UTC

pizlonator wrote: post #8

tiffanyh wrote: post #7

I see Lua was included, wish LuaJIT was as well.

I bet LuaJIT crushes Zef! Or rather, I would hope that it does, given how much more engineering went into it There are many runtimes that I could have included but didn’t. Also, it’s quite impressive how much faster PUC Lua is than QuickJS and Python

> it’s quite impressive how much faster PUC Lua is than QuickJS and Python

Python's execution time is mostly spent looking up stuff. I don't think lua is quite as dynamic.

Re: How to make a fast dynamic language interpreter

#10

Post by pizlonator » Tue, Apr 21, 2026, 4:20 AM UTC

zephen wrote: post #9

pizlonator wrote: post #8

Earlier quoted context omitted.

I bet LuaJIT crushes Zef! Or rather, I would hope that it does, given how much more engineering went into it There are many runtimes that I could have included but didn’t. Also, it’s quite impressive how much faster PUC Lua is than QuickJS and Python

> it’s quite impressive how much faster PUC Lua is than QuickJS and Python Python's execution time is mostly spent looking up stuff. I don't think lua is quite as dynamic.

Lua is way more dynamic