Depending on what other component libraries you’ve used, you may be used to handling events by passing callback functions to component properties, or using a special event syntax – Svelte supports both, though one is usually more appropriate than the other depending on your situation. This post explains both ways.

You should default to the most permissive option imo and there really is no reason to check anything until you really need to If it were left to me I'd just use optional chaining, as it also eliminates the need for no-ops

ensure the relevance, accuracy and effective communication of its interpretation and education programs (see above for A.O.D.A. requirements) by: establishing clearly defined and measurable learning objectives and outcomes, and undertaking a process of program evaluation using appropriate expertise – including staff, volunteers, community groups, or consultants carrying out research ensure all staff involved in the development and delivery of interpretation and education programs, have the appropriate skills and training

have a volunteer program to encourage community participation in its activities, which should include: identification and development of volunteer opportunities procedures for recruitment of volunteers matching the needs and interests of volunteers to those of the museum provision of appropriate training and supervision for volunteers provision of a safe and secure working environment for volunteers volunteer evaluation public and private recognition of volunteers' contributions

ensure the relevance, accuracy and effective communication of each exhibit by: establishing clearly defined objectives and evaluating exhibits against their objectives using appropriate expertise, including staff, volunteers, community groups, or consultants carrying out sufficient research ensure that all staff (including volunteers) involved in the planning, preparation and installation of exhibits have the necessary skills and training

formulating written policy governing operations and defining programs securing funding necessary to carry out the museum's programs preparing or approving an annual budget and monitoring it to ensure public accountability ensuring that the purposes for which the museum exists are being fulfilled

stored instructions a program and the act of writing these instructions down and getting the instructions to be correct programming.

{ item1: "hello", item2: "world" }

pic (a drawing language)

Note: The examples in Listings 10-17, 10-18, and 10-24 declare variables without giving them an initial value, so the variable name exists in the outer scope. At first glance, this might appear to be in conflict with Rust’s having no null values. However, if we try to use a variable before giving it a value, we’ll get a compile-time error, which shows that Rust indeed does not allow null values.

To the brain, reading computer code is not the same as reading language Neuroscientists find that interpreting code activates a general-purpose brain network, but not language-processing centers.

Original objects are never modified, but transparently wrapped by observable proxies.

Proxy = observable(object) Creates and returns a proxied observable object, which behaves just like the originally passed object. The original object is not modified.

Strings generated by devalue can be safely deserialized with eval or new Function

Svelte is its own language, not plain HTML+CSS+JS

My frustration is mainly from Svelte's choices that are very un-JavaScript-like. It doesn't have to be "like React/Vue". React is React because it doesn't restrict what you can do with JavaScript for the most part. It's just common FP practice to fold/map.

Review your own code first Write a clear changelist description Automate the easy stuff Answer questions with the code itself Narrowly scope changes Separate functional and non-functional changes Break up large changelists Respond graciously to critiques Be patient when your reviewer is wrong Communicate your responses explicitly Artfully solicit missing information Award all ties to your reviewer Minimize lag between rounds of review

It was great for three things: motivation (people used what I built!)feedback (they sent me the bugs they encountered)accountability (from the moment I tweeted about this publicly, I really felt like that I’d have to finish this project… otherwise, it would be embarrassing)

Turning my Jupyter-compatible Python code into Flask-compatible Python code took dozens of hours. I ran into small bugs and errors

I had a proof-of-concept. It was great, because when you do a project, there’s always that small uncertainty that your idea is stupid and it can’t be done at all. But when you have a working prototype, all that insecurity is gone and it becomes much easier to go on.

The point is: the initial idea should be simple—because even that will turn out to be pretty complex.

The problem with hobby projects is that they don’t pay very well. At least, compared to real-life projects. But hobby projects have a lot of cool advantages that we tend to forget.

The user has a starting stack: 10,000 units of play money.In each round, she gets a deal. Something like “You have an x% probability to win y amount of money.”She can decide how much of her play money she wants to risk.And the goal is to win as much as she can in 50 rounds.

This pattern can be neater syntactically because declaring a variable in a try block with let scopes the variable to the try block.

delete myObject.regex; // or, delete myObject['regex']; // or, var prop = "regex"; delete myObject[prop];

How about renaming this to something more meaningful:

Svelte's advantage here is that it indicates the need for an update at the place where the associated data is updated, instead of at each place the data is used. Then each template expression of reactive statement is able to check very quickly if it needs to rerender or not.

can you not also use a .babelrc?

Frontend frameworks are a positive sum game! Svelte has no monopoly on the compiler paradigm either. Just like I think React is worth learning for the mental model it imparts, where UI is a (pure) function of state, I think the frontend framework-as-compiler paradigm is worth understanding. We're going to see a lot more of it because the tradeoffs are fantastic, to where it'll be a boring talking point before we know it.

This conflicts in very basic ways with what other engineering disciplines expect. Toyota's stylists might be able to sell their renderings in art galleries, but you can't drive to work in one. In software, you can.

{...{ foo: null }} was getting serialized as foo="null" because spread() was checking for strict equality with undefined. It's now checking for loose equality with null.

When you’re implementing a bad plan yourself, instead of having a mentor bail you out by fixing it, a few really useful things happen:You learn many more details about why it was a bad idea. If someone else tells you your plan is bad, they’ll probably list the top two or three reasons. By actually following through, you’ll also get to learn reasons 4–1,217.You spend about 100x more time thinking about how you’ll avoid ever making that type of mistake again, i.e., digesting what you’ve learned and integrating it into your overall decision-making.By watching my mistakes and successes play out well or badly over the course of months, I was able to build much more detailed, precise models about what does and doesn’t matter for long-term codebase health. Eventually, that let me make architectural decisions with much more conviction.

being a programmer you should always make sure that you learn by yourself and create things by yourself

Thanks for posting this helpful, well written article. Learning programming, or any other thing one takes up, requires you to sit at one place have a plan of action for your study.

The challenges are very difficult and require great thinking ability to complete. If you are a beginner then it’s gonna be really tough for you.

Project Euler

It’s powered by a large set of problems to work with, and you can also gain access to the source codes that others used to solve the given coding challenges.

Conclusions Draw your own. No? Fine. Good Enough: JSON? Protobuf Cap’n Proto Flatbuffers CBOR msgpack Avoid: YAML XML Thrift? BSON

There’s a story about an art teacher that split their class in half. They told one half of the students that they’d be graded based on a single piece of work, and the other half that they would be graded on the quantity of work produced. The half that was being graded on quantity ended up producing higher quality pieces. By iterating and learning from their mistakes they actually ended up producing better work than the students that only had to produce one piece. Quantity leads to quality. Share your work Sharing work helps you to think and develop. The feedback you get feeds into the next iteration.

All containers without a --network specified, are attached to the default bridge network. This can be a risk, as unrelated stacks/services/containers are then able to communicate.

In terms of Docker, a bridge network uses a software bridge which allows containers connected to the same bridge network to communicate, while providing isolation from containers which are not connected to that bridge network. The Docker bridge driver automatically installs rules in the host machine so that containers on different bridge networks cannot communicate directly with each other.

In practice, functional programming is all about hiding for loops, which are abstracted away by the mapper functions that automate the iteration.

Declarative programming is an enabler of abstraction. Imperative programming is an inhibitor of abstraction. Declarative programming allows you to say “I want this and I don’t care how I get it” while imperative programming requires you to define each and every step.

Your weekly reminder that1. You should not have your development process on a centralized platform, at least not if you're doing anything that smells of copyright issues2. If you do host on a centralized platform, have regular, decentralized backups of code and issue tracking.3. Also, avoid US-centric hosting for this kind of thing. But really, refer to 1.

The reason that this solves our problem is: we now have full control over the module loading order. Whatever the import order in internal.js is, will be our module loading order.

Informative data about objects that are considered prototypes for the role. Base concept is similar to type, but without inheritance of limitations and properties. Base concepts are designed as a substitute for inheritance for external concepts. A base concept is like a related concept except that the base concept is almost identical to the role definition.

Longstanding controversy surrounds the meaning of the term "hacker". In this controversy, computer programmers reclaim the term hacker, arguing that it refers simply to someone with an advanced understanding of computers and computer networks[5] and that cracker is the more appropriate term for those who break into computers, whether computer criminals (black hats) or computer security experts (white hats).

The lodash/fp module promotes a more functional programming (FP) friendly style by exporting an instance of lodash with its methods wrapped to produce immutable auto-curried iteratee-first data-last methods.

If you define a variable outside of your form, you can then set the value of that variable to the handleSubmit function that 🏁 React Final Form gives you, and then you can call that function from outside of the form.

JavaScript is, of course, a dynamic language that allows you to add and remove objects and their members at any point in time. For many, this is precisely why they enjoy the language: there are very few constraints imposed by the language.

We rarely, if ever, start with a completely blank file and start writing code. More often that not we start by copying an existing file and then modifying it to get our result.

All validators can be used independently. Inspried by functional programming paradigm, all built in validators are just functions.

FormValidation.validators.creditCard().validate({

FormValidation.formValidation(formElement

One of the primary tasks of engineers is to minimize complexity. JSX changes such a fundamental part (syntax and semantics of the language) that the complexity bubbles up to everything it touches. Pretty much every pipeline tool I've had to work with has become far more complex than necessary because of JSX. It affects AST parsers, it affects linters, it affects code coverage, it affects build systems. That tons and tons of additional code that I now need to wade through and mentally parse and ignore whenever I need to debug or want to contribute to a library that adds JSX support.

Furthermore, JSX encourages bad non-dry code. Having seen a lot of JSX over the past few months, its encourages copypasta coding.

However, as a developer that uses JSX, I find it too useful/concise to give up in the name of syntax purity, especially when I know that what it translates to is still very isolated and computationally pure.

The problem is that not all tooling supports adding new dependencies from a transform. The first step is figuring out how this can be done idiomatically in the current ecosystem.

By using HTML as the uniform interface, we can separate the interface from the engine.

interfaces

Event itself contains the properties and methods which are common to all events.

An onevent event handler property serves as a placeholder of sorts, to which a single event handler can be assigned. In order to allow multiple handlers to be installed for the same event on a given object, you can call its addEventListener() method, which manages a list of handlers for the given event on the object.

Interface specifications can be reused through inheritance but implementation need not be.

The existing interface is closed to modifications and new implementations must, at a minimum, implement that interface.

"Objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program." See also design by contract.

functional-dominant hybrid style of programming

express one's model of Existence

create patterns & metaphor

that does not mean that I am advocating the other extreme–i.e., a templating language that allows a lot of logic. I find such templating languages, especially those that allow the host programming languages to be used inside the template, to be hard to read, hard to maintain, and simply a bad choice.

An alternative (maybe not good) would be to restrict {@const} to certain blocks like {#each} and {#if}. In both cases, it significantly reduces the "multiple ways to do the same thing" problem and avoids ergonomic and performance overhead of our current situation.

it also allows for more divergence in how people write there code and where they put their logic, making different svelte codebases potentially even more different due to fewer constraints. This last point is actually something I really value, I read a lot of Svelte code by a lot of different people and broadly speaking things look the same and are in the same places.

some programming languages that provide lexical closures view encapsulation as a feature of the language orthogonal to object orientation.

use code to parameterize calls:

python -c "
from mymodule import set_dragon_feeding_schedule, Creatures, Date
set_dragon_feeding_schedule(
    feeding_times=['10:00', '14:00', '18:00'],
    dishes={Creatures.Tiger: 2, Creatures.Human: 1},
    start_day=Date('1020-03-01'),
)
"

python -m mymodule \
    set_dragon_feeding_schedule \
    --feeding-times ['10:00','14:00','18:00'] # hopefully this way it gets recognized \
    # how will you define parsing a dict with enum to integer mapping? 
    --dishes=Creatures.Tiger:2 \
    --dishes=Creatures.Human:1 \
    --start-day=1020-03-21 # BTW bash allows no comments in multiline calls

That’s it. Types are parsed, checked and converted. Defaults and description are picked from function itself. Even provides bash completions you can install. You wrote no code for that!

import typer
from pathlib import Path

app = typer.Typer()

@app.command()
def find_dragon(name: str, path: Path, min_age_years: int = 200):
    <implementation goes here>

@app.command()
def feed_dragon(dragon_name: str, n_humans: int = 3):
    <implementation goes here>

if __name__ == "__main__":
    app()

python example.py find_dragon 'Drake' --path /on/my/planet

NestedText is a file format for holding data that is to be entered, edited, or viewed by people. It allows data to be organized into a nested collection of dictionaries, lists, and strings. In this way it is similar to JSON, YAML and TOML, but without the complexity and risk of YAML and without the syntactic clutter of JSON and TOML.

Pointing someone to a README.md does not lead to learning.

Solid supports templating in 3 forms JSX, Tagged Template Literals, and Solid's HyperScript variant.

Although I also work with solid in my day job at inrupt, I wrote this guide in my spare time.

I saw object proxies being the solution to doing diffing so that this approach could compete in any scenario that a VDOM could

So how do we declare the variable y to be the value of x plus 5? That's where reactive programming comes in. Reactive programming is a way of programming that makes it possible solve this problem

Here's a proxy store I wrote to derive the value of a store nested within other stores, it plays nice with typescript and can go infinitely deep

What is an iterable object in JavaScript? It’s an object that supports the iterable protocol.

no gradient tapes, no graph definitions requires

Today we begin the Early Access Program for Code With Me, a tool for remote collaborative development and pair programming that you have long been waiting for.

Indeed, this simple contract is very close to that of an ob­serv­able, such as those provided by Rxjs. set is basically equiv­a­lent to next in the ob­serv­able world.

The $ contract for auto-sub­scrib­ing is lovely in its sim­plic­ity and flex­i­bil­ity. You can adapt your own preferred state-man­age­ment pattern or library, with or without Svelte stores as helpers. Svelte does not fuss about how you want to manage your state.

However, IMO, having the conditional in the detach function is necessary, because there are other manifestations of this error. For example, if the DOM element in a component is removed from software outside of svelte, detach will have the same error.

IMO, the conditional needs to be added to detach to fix all manifestations of this error.

detach, as an api, should be declarative (ensure the node is detached) instead of imperative (detach the node), allowing it to be called multiple times by performing a noop if the node is already detached. This way, it won't matter if the node is removed from the DOM from outside of svelte.

Spending more time looking for a solution rather than thinking about it.

The benefit of this approach is that rather than having these defaults and fighting against them, it’s fully up to you to decide how to handle everything.

Then, the projects that use these libraries get to process these import statements how they like when they are bundled. For the ones that wish to load jQuery from a global, we again mark 'jquery' as an external—since we still don't want Rollup to bundle jQuery—and as a global.

I wrote hundreds of Rect components and what I learned is that Componets should be able to be styled by developer who is using it.

feel like there needs to be an easy way to style sub-components without their cooperation

The idea of a web browser being something we can comprehend, of a web page being something that more people can make, feels exciting to me.

There is a good amount of properties that should mostly be applied from a parent's point of view. We're talking stuff like grid-area in grid layouts, margin and flex in flex layouts. Even properties like position and and the top/right/left/bottom following it in some cases.

The main reason using classes isn't a great solution is that it completely breaks encapsulation in a confusing way, the paren't shouldn't be dictating anything, the component itself should. The parent can pass things and the child can choose to use them or not but that is different: control is still in the hands of the component itself, not an arbitrary parent.

The RFC is more appropriate because it does not allow a parent to abritrarily control anything below it, that responsibility still relies on the component itself. Just because people have been passing classes round and overriding child styles for years doesn't mean it is a good choice and isn't something we wnat to encourage.

For my point of view, and I've been annoyingly consistent in this for as long as people have been asking for this feature or something like it, style encapsulation is one of the core principles of Svelte's component model and this feature fundamentally breaks that. It would be too easy for people to use this feature and it would definitely get abused removing the style safety that Svelte previously provided.

Ideally: Only let a parent control those specific CSS properties, and never let a child use them on the root element.

margin, flex, position, left, right, top, bottom, width, height, align-self, justify-self among other is CSS properties that should never be modified by the child itself. The parent should always have control of those properties, which is the whole reason I'm asking for this.

I think Svelte's approach where it replaces component instances with the component markup is vastly superior to Angular and the other frameworks. It gives the developer more control over what the DOM structure looks like at runtime—which means better performance and fewer CSS headaches, and also allows the developer to create very powerful recursive components.

Lets not extend the framework with yet another syntax

Yup.ref('value')

Often, allowing the parents to compose elements to be passed into components can offer the flexibility needed to solve this problem. If a component wants to have direct control over every aspect of a component, then it should probably own the markup as well, not just the styles. Svelte's slot API makes this possible. You can still get the benefits of abstracting certain logic, markup, and styles into a component, but, the parent can take responsibility for some of that markup, including the styling, and pass it through. This is possible today.

As you can see, this would mean that a change in a component is potentially no longer isolated to that component, and the entire codebase should be checked to see if anybody has been overriding the default styles.

One of the main reasons to work with components is re-usability and portability, but also a delegation of responsibilities. Adding a component should be as easy as simply adding the component without having to know the inner workings (or markup) of this component. A consumer should only be aware of the properties, methods and events of a component. In order to style a child component one has to be aware of the markup as well, which violates this 'delegation of responsibility'-principle.

Your styles are scoped to the component. No more leakage, no more unpredictable cascade.

It's fashionable to dislike CSS. There are lots of reasons why that's the case, but it boils down to this: CSS is unpredictable. If you've never had the experience of tweaking a style rule and accidentally breaking some layout that you thought was completely unrelated — usually when you're trying to ship — then you're either new at this or you're a much better programmer than the rest of us.

Svelte, on the other hand, is a compiler. In a way, Svelte is more like a programming language than a library.

A paradigm is a model or pattern. In JavaScript, there are a number of popular paradigms including object-oriented programming (OOP) and functional programming (FP). Paradigms are more important than is sometimes recognized. They help form mental models for solving problems. Becoming well-versed in the principles of a given paradigm can help accelerate development by providing mental shortcuts for solving the challenges that arise while building applications. They can also help produce higher quality software.

we need to step back and make a closer look at the DRY principle. As I mentioned earlier, it stands for "Don’t Repeat Yourself" and requires that any piece of domain knowledge has a single representation in your code base. The words domain knowledge are key here. DRY is not about duplicating code. It is specifically about duplicating domain knowledge

We wanted a library designed specifically for a functional programming style, one that makes it easy to create functional pipelines, one that never mutates user data.