The latest lesson in the Python course is about functions that produce simple never-ending iterators. The ability to represent concepts like “counting upward from one” and “repeating an item indefinitely” is a big part of what distinguishes iterators from lists in Python. In Haskell we describe things like Python iterators as “lazy” because elements are not evaluated until they are needed. Python lists, in contrast, we describe as “strict”.
We just started a new section of the site called “Featured functions” which will house quick overviews of functions that we think deserve some extra love and attention. The first two featured functions are mapMaybe and intercalate.
Web Servers lesson 12 is about connection persistence – reusing the same socket for multiple HTTP requests. We write two versions of the server, one using lazy I/O and the other using strict
We have new lessons in two of our ongoing courses. In the fourth installment of the Timepieces course, Julie examines how the hierarchy of
fltkhs is meant to mirror that of FLTK. The latest lesson in the Web Servers course is about parsing message bodies. And we’ve added to our documentation of GHC language extensions with an article on
This week we’re excited to bring you a new lesson in the native GUI course. In this lesson, Chris uses gtk3, Pango, and TVars to transform the blank application window into a clock. And the latest lesson in the Functortown course, in which Julie introduces the laws of the Bifunctor class and goes into more detail about how ranges and shrinkage work when you’re property testing with hedgehog.
Everyone who has an active Type Classes subscription as of today can get the book for free on Leanpub; check your account page under the section entitled “Leanpub coupons”. The link can be used twice, so you can give a copy to a Haskell-curious friend.
We’ve released Web Servers lesson 9, Parsing requests, which continues our study of HTTP and gives a practical introduction to Attoparsec. We also continue to show how to ask GHCi for help with guides for using the beloved typed holes feature, all the uses of underscores, and warnings related to unused values.
This week we made some billing changes: There’s now an annual billing option in addition to monthly, and we now offer region-based discounts. We also took some time to publish a lot of the code that we use to work the Stripe API. You can find the code in the typeclasses/stripe repository on GitHub.
Our first Template Haskell article focuses on one narrow use case: Compile-time evaluation of constant expressions. Because we care dearly about avoiding sources of runtime errors wherever possible.
Julie presented a workshop on maximizing the useful information you can get from GHCi. It wasn’t recorded, but we’re working on getting all that information onto the site for our subscribers.
Check out our new Haskell tip, entitled Strict, lazy, and builder – It covers the various string types in the
Julie gave the keynote at C∘mp∘se :: Melbourne and we launched our new career as Haskell pamphleteers!
We’ve started releasing the web servers course, which will explain a lot about HTTP and how to write network applications in Haskell.
I chose the “Validation” course to be our flagship course on Type Classes because it’s material I’ve tested with meetup groups. Taking the same starting point as one of my more popular blog posts, it successively refactors relatively simple code until we’ve learned about several of Haskell’s most important features.
We’ve added additional video formats, so videos should now be working on most devices. This post includes some details on how the HTML
<video> tag supports multiple formats and how we generate DASH and HLS encoded versions of our videos.
Haskell Summer School has wrapped up, and we are back to work. Recordings of our classes are available.
“A monoid is a pipeline of functions”? Be careful not to get lost in a particular example for a typeclass.
Since our initial Type Classes announcement, we’ve been asked a number of questions about payments and planned content. Find out what’s available now, when we’ll start taking payments, and what you can expect as a subscriber.
On February 24, 1988, Philip Wadler introduced the idea of type “classes” for Haskell, as a solution to the problem of overloading. Thirty years later, we present Type Classes: a series of focused video courses on Haskell, Nix, and related subjects.