A NackClass is the same as NilClass except for any method it does not recognize, it return the instance of itself. nack.nack.nack.nack #=> nack Note I used to call this NullClass, but "nack" seems a little more fitting a term.

To be just a bit polemic, your first instinct was not to do that. And you probably wouldn't think of that in your unit tests either (the holy grail of dynamic langs). So someday it would blow up at runtime, and THEN you'd add that safeguard.

You can just leave your website at that address (it'll give you some serious street cred in the developer world), but if you have a custom domain you would like to use, it is very simple to make GitHub redirect your page. Log in to your domain registrar and find where to change your host records. If you don't know, you can usually Google "(domain registrar) change host records", and your registrar will have an explainer telling you how to do it. Change your domain's A Record to 204.232.175.78. This is GitHub's IP address, which allows GitHub to resolve your URL and serve the correct files. In your website's directory folder on your computer, create a file called "CNAME". On the first line, type your domain name. Save the file. In your GitHub application, you should see the file in the left column. Make sure it is checked and enter your commit message. Have it say something like "Adding CNAME file." Click "Sync branches." It can take as long as 48 hours for your domain to resolve to your GitHub page. However, it is usually pretty quick, so check back in an hour or so.

Underneath that awkward Java-esque patina, JavaScript has always had a gorgeous heart.

Nix is a purely functional package manager. This means that it treats packages like values in purely functional programming languages such as Haskell — they are built by functions that don’t have side-effects, and they never change after they have been built.

Optimize imports

Larry Wall famously said he was driven to create Perl by how difficult it was to solve a problem while coding, as well as by an abundance of 'laziness, impatience and hubris'

the impetus may have been more the challenge of creating a language of his own.

To an outsider, creating your own programming language might seem akin to saying 'I'll build my own airplane

Environment variables are 'exported by default', making it easy to do silly things like sending database passwords to Airbrake.

This naming convention helps developers understand the component’s contract

Reason is not a new language; it's a new syntax and toolchain powered by the battle-tested language, OCaml.

We might have some dirty mutable objects for performance - but our high-level API should be purely functional. You should be able to follow the React model of modelling your UI as a pure function of application state -> UI.

the abstraction I wished to have was a sort of a pure functional Vim, completely decoupled from terminal UI - where 'vim' is a function of (editor state, input) => (new editor state)

enquo() uses some dark magic to look at the argument, see what the user typed, and return that value as a quosure

If you love Ruby, you'll enjoy CoffeeScript as it makes the JavaScript more like the Ruby.

In 2017, I rewrote it again as a ClojureScript application, and it was only 500 lines of code! Holy cow!!!

For example the following pattern: (let [x true y true z true] (match [x y z] [_ false true] 1 [false true _ ] 2 [_ _ false] 3 [_ _ true] 4)) ;=> 4 expands into something similar to the following: (cond (= y false) (cond (= z false) (let [] 3) (= z true) (let [] 1) :else (throw (java.lang.Exception. "No match found."))) (= y true) (cond (= x false) (let [] 2) :else (cond (= z false) 3 (= z true) 4 :else (throw (java.lang.Exception. "No match found.")))) :else (cond (= z false) (let [] 3) (= z true) (let [] 4) :else (throw (java.lang.Exception. "No match found.")))) Note that y gets tested first. Lazy pattern matching consistently gives compact decision trees. This means faster pattern matching. You can find out more in the top paper cited below.

reactions bridge reactive and imperative programming

The problem with the annotation notion is that it's the first time that we consider a piece of data which is not merely a projection of data already present in the message store: it is out-of-band data that needs to be stored somewhere.

many of the searches we want to do could be accomplished with a database that was nothing but a glorified set of hash tables

There are objects, sets of objects, and presentation tools. There is a presentation tool for each kind of object; and one for each kind of object set.

That said, most Clojure programs begin life as text files, and it is the task of the reader to parse the text and produce the data structure the compiler will see

Good general theory does not search for the maximum generality, but for the right generality.

I was so fed up of the mega amounts of boilerplate with Redux and the recommendation of keeping your data loading at view level. It seems to me that things like this, with components being responsible for their own data, is the way to go in the future.

Null Coalescing Operator

Entities are the applications, services, and files in the ARGON worldview

In 1947, a high-flying moth bumped into Harvard’s Mark II Aiken Relay Calculator, was removed by computer operator William Burke, and then taped to the computer log - popularizing the existing term “debugging.”Figure 4: debugging

Go Programming Language publicly in 2009 they were also looking to solve certain challenges of the existing Computer languages. Of the many features that it demonstrated (we will get to those soon enough) it was also helpful in addressing the strange dilemma of hardware and software that was emerging.

we process millions of transactions per day here and we really need someone with more relevant experience who can handle these things without ramping up

I want to stop putting comments in my code. I want it to be first-class for my code to be in the left pane and my comments to be in the right pane, always binded together with anchors but always separate so my comments don't have to adhere to the limitations of the code's text area.

(if (instance? Throwable ret)

:ok

(fn [system] (throw (ex-info "initializer not set, did you call `set-init`?" {}))))

The Women Who Contributed to Science but Were Buried in Footnotes

for example, comments and identifiers

If one object is part of another object, then we use a diamond at the start of the arrow (next to the containing object), and a normal arrow at the end.

Grid devices can be nested or layered along with other devices and your plug-ins,

after the terminal operation of the stream pipeline commences.

Full disclosure: I’m a co-maintainer of clj-time and I’m pretty vocal about encouraging people not to use clj-time when starting a new project: use Java Time instead. Conversion from an existing, clj-time-heavy project is another matter tho’, unfortunately.

Meditation can not only provide a welcome counterweight to this work with abstractions, it also cultives 10 qualities of character (Pali: paramis) that are useful during the practice of programming.

One thing Component taught me was to think of the entire system like an Object. Specifically, there is state that needs to be managed. So I suggest you think about -main as initializing your system state. Your system needs an http client, so initialize it before you do anything else

For the sweet spot you're looking for, I suggest being clear about if you're designing or developing. If you're designing and at the REPL, force yourself to step away with pen and paper after you've gotten some fast feedback.

Re-open libraries for exploration I use in-ns to jump into library namespaces and re-define their vars. I insert bits of println statements to help understand how data flows through a library. These monkey-patches only exist in the running REPL. I usually put them inside a comment form. On a REPL restart, the library is back at its pristine state. In this example below, I re-open clj-http.headers to add tracing before the header transformation logic: [source] ;; set us up for re-opening libraries (require 'clj-http.headers) (in-ns 'clj-http.headers) (defn- header-map-request [req] (let [req-headers (:headers req)] (if req-headers (do (println "HEADERS: " req-headers) ;; <-- this is my added print (-> req (assoc :headers (into (header-map) req-headers) :use-header-maps-in-response? true))) req))) ;; Go back to to the user namespace to test the change (in-ns 'user) (require '[clj-http.client :as http]) (http/get "http://www.example.com") ;; This is printed in the REPL: ;; HEADERS: {accept-encoding gzip, deflate} An astute observer will notice this workflow is no different from the regular clojure workflow. Clojure gets out of your way and allows you to shape & experiment in the code in the REPL. You can use this technique to explore clojure.core too!

Unmap namespaces during experimentation I use ns-unmap and ns-unalias to remove definitions from my namespace. These are the complementary functions of require and def. While exploring, you namespace will accrue failed experiments, especially around naming. Instead of using a giant hammer [tools.namespace], you can opt for finer-grained tools like these. Example: (require '[clojure.string :as thing]) (ns-unalias *ns* 'thing) ; *ns* refers to the current namespace

That is using a specific tool for a specific use case. You don’t actually have a table view of your data. Once it’s in a table, man, you’re good. That is the modeling. A sequel database table, you have this amazing high-level language for doing all sorts of cool operations with it.To turn this into some class hierarchy, it’s almost criminal. There, I said it. It’s like you’re throwing away the power that you have.

A lot of this would be a non issue if we had end user programming. The problem today is that 'configurability' is itself something the programmer needs to implement

Configuration knowledge is anti-knowledge -- learning how to conform to the inessential quirks of a system somebody else made up

1 reply 1 retweet 5 likes Reply 1 Retweet 1 Retweeted 1 Like 5 Liked 5 Direct message Omar Rizwan‏ @rsnous Feb 16 More Copy link to Tweet Embed Tweet Mute @rsnous Unmute @rsnous Block @rsnous Unblock @rsnous Report Tweet Add to other Moment Add to new Moment Replying to @rsnous @disquiet07 files are a weak lowest-common-denominator interface between programs in different languages (C, Python, Ruby, Swift, VB, bash, etc) in ecosystems with one language (iOS, JS, Lisp, Smalltalk), you often don't see files: you just persist the rich native structures of the language 4 replies 2 retweets 16 likes Reply 4 Retweet 2 Retweeted 2 Like 16 Liked 16 Direct message Gordon Brander‏ @gordonbrander 3h3 hours ago More Copy link to Tweet Embed Tweet Mute @gordonbrander Unmute @gordonbrander Block @gordonbrander Unblock @gordonbrander Report Tweet Add to other Moment Add to new Moment Replying to @rsnous @disquiet07 OTOH — lowest common denominator interfaces allow for emergent behavior. They focus all the constraints in one place, leaving the rest of the system definition open-ended. Like defining the LEGO dot, but not what shape pieces may take. 1 reply 0 retweets 3 likes Reply 1 Retweet Retweeted Like 3 Liked 3 Direct message Omar Rizwan‏ @rsnous 2h2 hours ago More Copy link to Tweet Embed Tweet Mute @rsnous Unmute @rsnous Block @rsnous Unblock @rsnous Report Tweet Add to other Moment Add to new Moment Replying to @gordonbrander @disquiet07 With files, imo the lack of structure 1. forces duplication of functions at the app level (de/serialization, cross-links, …) and 2. prevents coordination for higher-level behavior #1 here seems different from LEGO, but I can't quite articulate it in terms of your analogy 1 reply 0 retweets 2 likes Reply 1 Retweet Retweeted Like 2 Liked 2 Direct message Gordon Brander‏ @gordonbrander 2h2 hours ago Follow Follow @gordonbrander Following Following @gordonbrander Unfollow Unfollow @gordonbrander Blocked Blocked @gordonbrander Unblock Unblock @gordonbrander Pending Pending follow request from @gordonbrander Cancel Cancel your follow request to @gordonbrander More Copy link to Tweet Embed Tweet Mute @gordonbrander Unmute @gordonbrander Mute this conversation Unmute this conversation Block @gordonbrander Unblock @gordonbrander Report Tweet Add to other Moment Add to new Moment Replying to @rsnous @disquiet07 I agree. Low-level interop has a high floor, high ceiling. Higher-level interop (like Smalltalk) has lower floors, because deeper system integration. However, that deeper integration often means you end up more entangled with the system’s strengths and weaknesses.

Rob Pike has described Plan 9 as "an argument" for simplicity and clarity, while others have described it as "UNIX, only moreso."

In computer science and logic, a dependent type is a type whose definition depends on a value. A "pair of integers" is a type. A "pair of integers where the second is greater than the first" is a dependent type because of the dependence on the value.

On the flip side, it can go further than mere types, including emulating dependent types and programming-by-contract.

Perhaps part of the confusion - and you say this in a different way in your little memo - is that the C/C++ folks see OO as a liberation from a world that has nothing resembling a first-class functions, while Lisp folks see OO as a prison since it limits their use of functions/objects to the style of (9.). In that case, the only way OO can be defended is in the same manner as any other game or discipline -- by arguing that by giving something up (e.g. the freedom to throw eggs at your neighbor's house) you gain something that you want (assurance that your neighbor won't put you in jail).

Sum-of-product-of-function pattern - objects are (in effect) restricted to be functions that take as first argument a distinguished method key argument that is drawn from a finite set of simple names.

All you can do is send a message (AYCDISAM) = Actors model - there is no direct manipulation of objects, only communication with (or invocation of) them. The presence of fields in Java violates this.

Parametric polymorphism - functions and data structures that parameterize over arbitrary values (e.g. list of anything). ML and Lisp both have this. Java doesn't quite because of its non-Object types.

Ad hoc polymorphism - functions and data structures with parameters that can take on values of many different types.

Encapsulation - the ability to syntactically hide the implementation of a type. E.g. in C or Pascal you always know whether something is a struct or an array, but in CLU and Java you can hide the difference.

Following Christopher Strachey,[2] parametric polymorphism may be contrasted with ad hoc polymorphism, in which a single polymorphic function can have a number of distinct and potentially heterogeneous implementations depending on the type of argument(s) to which it is applied. Thus, ad hoc polymorphism can generally only support a limited number of such distinct types, since a separate implementation has to be provided for each type.

In programming languages and type theory, parametric polymorphism is a way to make a language more expressive, while still maintaining full static type-safety. Using parametric polymorphism, a function or a data type can be written generically so that it can handle values identically without depending on their type.[1] Such functions and data types are called generic functions and generic datatypes respectively and form the basis of generic programming.

One is the linked list of lines you mention. I believe this is intended to solve a display problem that TECO (the original language in which Emacs was implemented) had solved differently using the "gap" data structure. The fundamental issue was that if you have a buffer represented as a single block of contiguous text, then insertion on a character-by-character basis can be O(n2), each time you insert a character, you have to copy the entire subsequent buffer over one space.

Lisp macros were also useful for the definition of new control structures, as well as new data structures. In ZWEI, we created a new iterative control structure called charmap, which iterates over characters in an interval. Intervals are stored as doubly-linked lists of arrays, and the starting point might be in the middle of one array and the ending point might be in the middle of another array. The code to perform this iteration was not trivial, and someone reading it might easily not understand the function it was performing, even though that function was the conceptually simple one of iterating over characters. So we created a macro called charmap that expands into the double-loop code to iterate over the characters. It is simple and obvious, and is used in many places, greatly reducing the size of the code and making the functionality obvious at a glance.

It became policy to avoid abbreviations in most cases. In ZWEI, we made a list of several words that were used extremely often, and established 'official' abbreviations for them, and always used only those abbreviations. ... Words not on this list were always spelled out in full.

Some paragraphs are devoted to what must have been a novel concept at the time for such a system: that the Lisp Machine was a personal system, not time-shared, and this gave rise to features not viable on time-sharing systems, due to the fact that the user was not contending with other users for resources.

Wehler et al38 reported that homeless and low-income mothers who experienced sexual assault in childhood were over 4 times more likely to have household level food insecurity than women who had not been abused

Use React for ephemeral state that doesn't matter to the app globally and doesn't mutate in complex ways. For example, a toggle in some UI element, a form input state. Use Redux for state that matters globally or is mutated in complex ways. For example, cached users, or a post draft. Sometimes you'll want to move from Redux state to React state (when storing something in Redux gets awkward) or the other way around (when more components need to have access to some state that used to be local).

Raccomandazione 3.6g - Definire un modello di governance del dato e progettare automatismi organizzativi e tecnologici

onDragStart

This behavior also argues for following the convention of placing an opening curly brace at the end of a line in JavaScript, rather than on the beginning of a new line. As shown here, this becomes more than just a stylistic preference in JavaScript.

(== 10)

Lucius Gregory Meredith, Mike Stay, and Sophia Drossopoulou. Policy as types. CoRR, 2013. URL: http://arxiv.org/abs/1307.7766.

type-safe enum pattern

a mutator method is a method used to control changes to a variable. They are also widely known as setter methods

class MyClassDef {

    public void setProperty(String propertyVal) { .. }

}