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Factor: an extensible interactive language

Google TechTalks

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  • Recommended by 8 people: 5 on Hacker News, 1 on Lobsters, 1 in engineering communities and 1 curated list.
  • A classic. People kept recommending it from 2014 to 2025.
  • Presented by Slava Pestov, creator of Factor

Intermediate. Assumes working knowledge.

59K views18 years ago8 recommendations

Programming languagesHistory and cultureLanguage design and type systemsFunctional programming

Slava Pestov introduces Factor, a concatenative, extensible programming language influenced by Forth, Lisp, and Smalltalk.

Google Tech Talks October 27, 2008 ABSTRACT Factor is a general-purpose programming language which has been in development for a little over five years and is influenced by Forth, Lisp, and Smalltalk. Factor takes the best ideas from Forth -- simplicity, succinct code, emphasis on interactive testing, meta-programming -- and brings modern high-level language features such as garbage collection, object orientation, and functional programming familiar to users of languages such as Python and JavaScript. Recognizing that no programming language is an island, Factor is portable, ships with a full-featured standard library, deploys stand-alone binaries, and interoperates with C and Objective-C. In this talk, I will give the rationale for Factor's creation, present an overview of the language, and show how Factor can be used to solve real-world problems with a minimum of fuss. At the same time, I will emphasize Factor's extensible syntax, meta-programming and reflection capabilities, and show that these features, which are unheard of in the world of mainstream programming languages, make programs easier to write, more robust, and fun. Speaker: Slava Pestov Slava was born in the former USSR and emigrated to New Zealand at the age of 7. He moved to Ottawa, Canada when he was 18 to study for a Bachelors and Masters degree in Mathematics. He now resides in Minneapolis, Minnesota. An early adopter of Java, Slava wrote the popular jEdit text editor, then went on to design and implement the Factor programming language. At his day job he hacks on web apps, optimizing compilers, garbage collectors, and everything in between.

Why it's here

8 people recommend this

What people say. Highly recommended by engineers as a mind-blowing introduction to concatenative programming and the Factor language.

u/cutculusin r/ProgrammingLanguages • Recommends

Factor: an extensible interactive language Video, 2008

xelxebaron Hacker News • Recommends

On “Concatenative language (2017)”

I just stumbled across this Google Tech Talk on factor0 last night! It absolutely blew my mind. The engineering looks to be top notch, and the video is 9 years old to boot! link to this video Anyway, really want to give Factor a try for some personal projects. Would love to hear anecdotes from people who futz with this stuff. 0: link

fud101on Hacker News • Recommends

On “Ask HN: Why did Python fail to evolve?”

It's funny because 3 dropped in 2008, the same year Slava was demonstrating Factor in google tech talks which was a contemporary language to python3 that completely blew Python out of the water. link to this video

programming-talkscurated list on GitHubRecommends

Under “Factor”

Factor: an extensible interactive language 01:36:39 by **Slava Pestov** (2008)

acon Lobsters • Recommends

Factor: an extensible interactive language (2008)

agumonkeyon Hacker News • Recommends

On “K, by Arthur Whitney (2005)”

I see what you did there. ps: just in case here's a very enjoyable talk, not about, but by Slava link to this video Beautiful and impressive.

benhoyton Hacker News • Recommends

On “Factor: A Practical Stack Languge”

As someone who built Forth compilers back in the day, I really like this language. There's a nice overview of Factor as a paper here: link and a Google tech talk video of Slava Pestov (Factor's creator) showing off the language here: link to this video

johnisgoodon Hacker News • Recommends

On “The V Programming Language”

I agree. I remember his talk on Factor. I wish people gave enough support back then so he could work on it full-time. Here is his talk on Factor: link to this video , back from 2008.

runekson Hacker News • Mentions

On “Pipes and Filters”

I recently came across a language called Factor that works very similar, if not identical, to this. Here's a video about it: link to this video

zoltaron Hacker News • Mentions

On “Thinking Forth: A Language and Philosophy for Solving Problems (2004) [pdf]”

…ambda f, g: lambda *xs, **ys: g(f(*xs, **ys)), fs) inline_board = rcompose( chess.Board, chess.svg.board, SVG, display) Factor's quotations dealing with stack management weirdness is super nice, too. link It still has a bit more stack juggling than I like, though. That could just be a "me" problem. Props to that whole community for their effort. link to this video…

johnisgoodon Hacker News • Mentions

On “Evolving the OCaml Programming Language (2025) [pdf]”

…re not part of the core language, they are in just as library".2 And to compare OCaml's type system to Python's is straight out absurd. 1 Locals are entirely implemented in Factor, too, which is only about ~500 lines of code. It is not part of the core language, and on top of that, there is no performance penalty whatsoever! 2 See more here: link to this video .…