« BackThe Little Typer (2018)thelittletyper.comSubmitted by aarestad 13 hours ago
  • ProllyInfamous 9 hours ago

    As a retired electrician attempting hobby-level "learn to code" (i.e. I don't know anything about modern programming and did not even understand anything from OP's link), this Amazon review helped me understand OP's link:

    >..I’ve been (slowly) working my way through The Little Typer. It’s a deep dive on dependent types, starting with the very basics and building up a toy language one step at a time. I can feel it gradually changing how I think about programming (heck, how I think about thinking).

    >..It’s really, really enjoyable. The format is very approachable, even fun. Rigorous and demanding, yet doesn’t take itself too seriously. Some lisp experience is helpful, but probably (maybe?) not necessary. But do yourself a favor and learn lisp anyway ;-)

    Maybe some day I'll motivate myself to even figure out how to first install Racket/Pie (first, I have to figure out what even these are).

    Thanks for the motivation/educational resource, OP.

    • rgrmrts 9 hours ago

      I’d recommend the earlier book in the series, The Little Schemer, for what it’s worth! It’s more aimed towards beginners. Similar format to this book.

      • ProllyInfamous 9 hours ago

        >The Little Schemer

        Inially wasn't sure if your comment was "a joke," but thanks for the real introduction:

        amazon.com/Little-Schemer-Daniel-P-Friedman/dp/0262560992/ [link to book]

        • Jtsummers 8 hours ago

          https://mitpress.mit.edu/author/daniel-p-friedman-4089/ - one of the authors on all the books in the series.

          The Little Schemer and The Seasoned Schemer are both beginner books using Scheme. The Reasoned Schemer uses Scheme + Minikanren, an extension of Scheme that allows for logical/relational programming (look up Prolog and Datalog as languages in the same vein). The Little Typer is the linked book covering type systems and, specifically, dependent typing. The Little Learner covers machine learning. The Little Prover uses the same format and has you develop proofs.

          Little, Seasoned, and Reasoned are, IMO, the better books in the series to start with. I found the later ones to be good but very dense and not always as clear, had to step back a lot more and reread sections. That's mostly due to the material being much harder and more technical than the earlier books, not a quality issue with the writing itself.

          My recommend reading order for someone with no Racket, Scheme, or Lisp experience wanting to tackle the series would be: Little -> Seasoned -> [Optional: Reasoned] -> {Any order: Prover, Typer, Learner}. I think Prover may be better before Typer, but it's been a while since I looked at either, so a soft recommendation of Prover -> Typer.

          If you have some Racket, Scheme, or Lisp experience, I'd suggest to either skim the first couple books to get used to the format or skip them entirely and use Reasoned as your first book in the series.

          http://minikanren.org

          • nextos 4 hours ago

            With no Scheme or programming background, I'd study HtDP (https://htdp.org) as an interlude, after The Little Schemer. Pace is gentle, and explanations about program design are long and very lucid. After those two, I'd try The Little MLer. The other books are quite advanced, better to build solid foundations first.

          • jfoutz 7 hours ago

            Friedman's books are all great. All of them. But they don't work for everybody.

            If you can be relaxed and think of the interaction as play, they're very good. If you're feeling more of a "serious business" mindset, it can be hard to get in the groove of his style.

            There are a lot of jokes about food and encouragement to take breaks. If you can get into the learning as play mindset, I'd strongly encourage taking the recommended breaks. maybe grab a snack, but spend some time noodling around with the ideas in each section. I think that's the real point, food is a good excuse to pause and get your hands off the keyboard.

            Racket should be easy to install. Big download button for a ton of platforms here - https://racket-lang.org

            I believe HN still runs on the racket runtime. it may appear to be a toy, but thoughtful design can take you a long long way. it's well supported and a great way to get started.

            If Friedman doesn't work out for you, the racket docs link to how to design programs - https://htdp.org/2024-8-20/Book/index.html Which is also pretty darn good.

            The other classic is the wizard book - https://sarabander.github.io/sicp/html/index.xhtml the structure and interpretation of computer programs. This'll walk you up to and somewhat through compilation.

            There are a ton of programming languages all with amazing assortments of features.

            Scheme is much more "there's nothing left to take away". I think it's very much the undisputed champion in that regard. While still being able to ship software. Scheme may not be the optimal choice for all people in all situations (obviously). It's a spectacular place to start though. It may not turn out to be the language for you. That's totally fine! But it'll get you deep enough to figure out what you like and don't like. And, when it comes down to it, you can shape it into pretty much anything.

            Yeah, I hope you enjoy the little schemer.

        • bmitc 8 hours ago

          Check this course out:

          https://www.edx.org/learn/coding/university-of-british-colum...

          I think you'll really like it. It uses Racket and is based upon the How to Design Programs book. It is absolutely perfect for someone new to coding.

        • kevindamm 11 hours ago

          I liked the dialogue-driven format of this and the others in the series (I've read Schemer and Learner too), at least once I got used to the split-mind feel of it, but I feel it would be better as an interactive media instead of the books.

          There's an expectation that you're following along and typing nearly every line into the appropriate REPL. I found this difficult to do while juggling the hardcopies and not any easier on an ebook reader -- I could stop worrying about cracking the spine but the digital copies I sampled or purchased always completely ruined the typesetting. All the REPL interactions are transcribed as images, and the constant focus-and-pinch-zoom disrupts the engagement.

          I ended up just reading through and hoping to catch enough of the gist of things then doing my usual side-project-as-learning instrument thing. I hope somebody tries to build an interactive playground for this book or the Little Learner, complete with guiding dialog.

          The typesetting in the hardcopies is really unique and impressive.

          • emmanueloga_ 4 hours ago

            For those looking for a more straightforward approach to type systems, here are two resources I like:

            1: Terence Parr's chapter "Enforcing Static Typing Rules" from Language Design Patterns.

            2: Eli Bendersky's Python implementation of Hindley-Milner type inference.

            --

            1: https://pragprog.com/titles/tpdsl/language-implementation-pa...

            2: https://eli.thegreenplace.net/2018/type-inference/

            • kccqzy 11 hours ago

              I bought this book when it first came out. Unfortunately this book required a time commitment greater than what I had available at that time and I didn't finish. It's thoroughly enjoyable (at least the first few chapters) but it requires a level of thinking that might not be available if you just finished a day of work.

              • Jtsummers 11 hours ago

                Three past discussions with discussion:

                https://news.ycombinator.com/item?id=18046745 - Sept 22, 2018 (132 comments)

                https://news.ycombinator.com/item?id=31465368 - May 22, 2022 (23 comments)

                https://news.ycombinator.com/item?id=33162971 - Oct 11, 2022 (96 comments)

                • ahelwer 11 hours ago

                  I worked through this a few years ago and it is wonderful, but I found chapter 9 on the replace function totally impenetrable, so I wrote a blog post in the same dialogue style intended as a gentler prelude to it. A few people have emailed me saying they found it and it helped them. https://ahelwer.ca/post/2022-10-13-little-typer-ch9/

                  • crdrost 11 hours ago

                    This is great for me for a completely auxiliary reason, which is that I wanted to know whether this was just gonna be a book about programming Fibonacci numbers into types or some ish... and in some ways it's kinda worse, at chapter 9 you are still proving that different takes on x→x+1 are the same. (But using rewrite rules seems kinda interesting in the abstract I guess.)

                    • ahelwer 8 hours ago

                      This series of books has always been aimed at people who want to implement the underlying systems. If you’re more interested in the application side of dependent types you might like the book Functional Programming in Lean by the same author, which is freely available online!

                  • RedNifre 10 hours ago

                    Is there an online community for this where you can ask questions? E.g. a discord server or an IRC channel?

                    • nextos 10 hours ago

                      I don't think there's a centralized community for the Little Series. I think this is unfortunate. With a community, some great titles like The Little MLer (typed FP) and A Little Java, a Few Patterns (OOP) would be much better known.

                      I found those two outstanding. I think A Little Java has been reprinted. But last time I checked, The Little MLer was bloody expensive. Standard ML, OCaml and F# need a lot more exposure. They are simple and practical. The Little MLer does a great job introducing the basics.

                      To close the circle, the Little Series is missing a book about concurrent and distributed paradigms à la Erlang. They already have functional programming, typed functional programming, declarative programming, dependent types, theorem proving, object-oriented programming and machine learning.

                      • soegaard 10 hours ago

                        You are welcome in the Racket Discord.

                        https://discord.com/invite/racket-571040468092321801

                        • RedNifre 9 hours ago

                          Thank you! I joined, but don't see a place for Pie, so I just asked about it in the beginner channel instead.

                        • ysangkok 5 hours ago

                          The Gay Haskell discord server has a channel for dependent types. There is also a discord server for Type Theory Forall, a podcast.

                        • philip-b 6 hours ago

                          I read it 2 years ago while I was sick with COVID. It was a lot of fun, it was pretty easy, but also very interesting. It was not a big time commitment. I learned a lot about dependent types. I recommend it.

                          • ducktective 10 hours ago

                            What modern scheme is best to use for these "the little x'er" book series? Some of them suggest their dialect (like learner suggests Racket I think), but what about others? In short, what scheme is the most practical and useful nowadays?

                            Here is the result of my research so far, in order of preference according to the above requirements:

                            Guile: most active community, GNU glue language, Guix

                            Chicken: most pragmatic one with a package manager but older

                            Chez: most performant one, less active community and libraries

                            • sporkl 2 hours ago

                              Racket! This is the language that the common author (Dr. Daniel Friedman) uses, and many of the Little books use custom DSLs implemented in Racket.

                              Racket now runs on Chez under the hood (inheriting the performance), and has a pretty decent ecosystem as far as schemes go.

                              (I TA for Dr. Friedman’s programming languages course)

                              • RedNifre 10 hours ago

                                This one comes with its own language, "Pie", which you can use in DrRacket with #lang pie

                                • nextos 10 hours ago

                                  Guile is great, but I think outside Guix it's pretty niche.

                                  Racket is probably the most frequent choice. But I really like some aspects of Chicken, Gambit and Bigloo.

                                  Even Clojure or CL could also be used, with a bit of friction of course.

                                  • wk_end 9 hours ago

                                    A book like this doesn’t need to be “practical” and “useful” - I don’t think, say, the shortage of libraries for Chez Scheme is going to hamstring you in anyway.

                                    • 4ad 10 hours ago

                                      I don't know what is the best Scheme implementation, but this book has little to do with Scheme though. Pie uses S-expressions for syntax, and happens to be implemented in Racket, but you don't interact with Racket directly.

                                      • matrix12 6 hours ago

                                        Gerbil scheme works great with the Schemer series of books.

                                      • davexunit 9 hours ago

                                        Guile is my Scheme of choice.