After considering the value we place, and the tradeoffs we make, when it comes to knowing anything of significance, I think it becomes much easier to understand why cache invalidation is one of the hard problems in computer science

The non-determinism is why cache invalidation — and that other hard problem, naming things — are uniquely and intractably hard problems in computer science. Computers can perfectly solve deterministic problems. But they can’t predict when to invalidate a cache because, ultimately, we, the humans who design and build computational processes, can’t agree on when a cache needs to be invalidated.

Cache invalidation is hard because: Everything in life we want to know, changes.Those changes are non-deterministic.

Sometimes humorously extended as “cache invalidation, naming things, and off-by-one errors.”

There’s only one hard thing in Computer Science: human communication. The most complex part of cache invalidation is figuring out what the heck people mean with the word cache. Once you get that sorted out, the rest is not that complicated; the tools are out there, and they’re pretty good.

One reason Turbolinks sites seem faster than traditional web apps is because of its cache. However, the cache can be a source of great frustration. Many of the edge cases we're going to discuss involve the cache in some way.

Turbolinks is a Single-Page Application Turbolinks doesn't just give you some of the benefits of a single-page app. Turbolinks is a single page app. Think about it: When someone visits your site, you serve them some HTML and Javascript. The JavaScript takes over and manages all subsequent changes to the DOM. If that's not a single-page app, I don't know what is.

Our app is mostly about displaying pages of static information. We crunch a lot of data to generate a single error report page.

Honeybadger isn't a single page app, and it probably won't ever be. SPAs just don't make sense for our technical requirements.

Flexbox's strength is in its content-driven model. It doesn't need to know the content up-front. You can distribute items based on their content, allow boxes to wrap which is really handy for responsive design, you can even control the distribution of negative space separately to positive space.

Flexbox is for one dimensional layout (row or column). CSS grid is for two dimensional layout.

There is one situation where iframes are (almost) required: when the contents of the iframe is in a different domain, and you have to perform authentication or check cookies that are bound to that domain. It actually prevents security problems instead of creating them. For example, if you're writing a kind of plugin that can be used on any website, but the plugin has to authenticate on another domain, you could create a seamless iframe that runs and authenticates on the external domain.

I normally try to figure out if that's a good solution for the problem before resorting to iframes. Sometimes, however, an iframe just does the job better. It maintains its own browser history, helps you segregate CSS styles if that's an issue with the content you're loading in.

Usually, if you can do it without an iframe, that is a better option. I'm sure others here may have more information or more specific examples, it all comes down to the problem you are trying to solve.

Slackmojis is made by some random dude in Brooklyn. He doesn't work for Slack, isn't paid by Slack, he just thinks Slack is pretty cool. Super Official Lawyer Talk: Slackmojis is not created by, affiliated with, or supported by Slack Technologies, Inc.

The code is far simpler and easier to understand/verify

Ubuntu also supports ‘snap’ packages which are more suited for third-party applications and tools which evolve at their own speed, independently of Ubuntu. If you want to install a high-profile app like Skype or a toolchain like the latest version of Golang, you probably want the snap because it will give you fresher versions and more control of the specific major versions you want to track.

if it's not broken, fix it until it is.

If components gain the slot attribute, then it would be possible to implement the proposed behavior of <svelte:fragment /> by creating a component that has a default slot with out any wrappers. However, I think it's still a good idea to add <svelte:fragment /> so everyone who encounters this common use case doesn't have to come up with their own slightly different solutions.

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.

Think first: why do you want to use it in the browser? Remember, servers must never trust browsers. You can't sanitize HTML for saving on the server anywhere else but on the server.

When there are imperfections, we rely on users and our active community to tell us how the software is not working correctly, so we can fix it. The way we do that, and have done for 15 years now, is via bug reports. Discussion is great, but detailed bug reports are better for letting developers know what’s wrong.

They may skim books for what they’ll “need to know.” They’re less likely to wonder, say, “How can we be sure that’s true?” than to ask “Is this going to be on the test?”

Nodes A wave function node occurs at points where the wave function is zero and changes signs. The electron has zero probability of being located at a node.

You’re in good companyTrusted by leaders at some of the world’s most inspired organizations

Maybe something more neutral just meaning a virtual element / no-element container would better express the intention? And regarding the syntax, maybe it would also feel less repetitive / boilerplaty than <svelte:slot slot="name" />... Maybe something like <svelte:fragment slot="name"> or <svelte:virtual slot="name">?

more leading edge than bleeding

Is using bleeding edge tech risky and foolish? How much blood are we talking about? My experience tells me Svelte is a safe choice, more leading edge than bleeding.

Magnetic materials are always made of metal, but not all metals are magnetic

If only Santa Anna had not repealed the Constitution of 1824. If only Santa Anna had not dissolved the legislatures. If only Santa Anna had not killed every Texan prisoner. If only Santa Anna had not gone to sleep without posting a guard at San Jacinto. If only Santa Anna had done any of these things Texas would probably still be a Mexican state; however, Santa Anna did none of these things. In fact it was his failure to do any of these things that caused Texas to become an independent republic.

At first Santa Anna's policy of execution carried the desired effect; all the Texans ran toward the American border (see map). However, his policy backfired. All the weak hearted Texan soldiers quit the army leaving only the hard core men.

These are sequential because build:ssr imports the public/index.html that build:dom produces.

I wouldn't use Flutter for web, mobile is good though.

It's super promising for web apps, just maybe not for web pages. I went from React to Svelte to Flutter for my current app project, and every step felt like a major upgrade.Flutter provides the best developer experience bar none, and I think it also has the potential to provide the best user experience. But probably only for PWAs, which users are likely to install anyway. Or other self-contained experiences, like Facebook games. It does have some Flash vibes, but is far more suitable for proper app development than Flash ever was while still feeling more like a normal website to the average user. It won't be the right choice for everything, but I believe it will be for a lot of things.

Fallback values aren't used to fix the browser compatibility. If the browser doesn't support CSS custom Properties, the fallback value won't help.

Secondary buttons are the ‘go back’ to the primary button’s ‘next’, or the ‘cancel’ button to the ‘submit’ button

I hope @hperrin you're still alive to discuss about this and eventually for a pull request.

After i've stabilized the library i can start to discuss about adding new components and features!

@monkeythedev can your work be used already? I would suggest not yet, i'm still doing core changes every day

@monkeythedev I am curious how do you "organize" your work - You forked https://github.com/hperrin/svelte-material-ui and https://github.com/hperrin/svelte-material-ui is not very active. Do you plan an independent project ? I hope the original author would return at some times, if not, i'll see

Maybe @hperrin would be able to make an appearance and select a few additional maintainers to help out.

passive: true instructs chrome that no body will call e.preventDefault() so chrome can optimized scrolling just because no body will call e.preventDefault and so there is no need to wait listeners...

Who’s Using Snowpack?

If everyone did this, the repair shops would be out of business.

Used by folks at

This module should not be used in other npm modules since it modifies the default require behavior! It is designed to be used for development of final projects i.e. web-sites, applications etc.

Alexanderproposeshomesandofficesbedesignedandbuiltbytheireventualoccupants.Thesepeople,hereasons,knowbesttheirrequirementsforaparticularstructure.Weagree,andmakethesameargumentforcomputerprograms.Computerusersshouldwritetheirownprograms.KentBeck&WardCunningham,1987 [7]

Connected to this are Andy Matuschak’s comments about contextual backlinks bootstrapping new concepts before explicit definitions come into play.

Easily updated pages: don’t worry about precisely naming something at first. Let the meaning emerge over time and easily change it (propagating through all references).

Cognitive Overhead (aka Cognitive Load): often the task of specifying formalism is extraneous to the primary task, or is just plain annoying to do.

The basic intuition is described well by the Shipman & Marshall paper: users enter information in a mostly informal fashion, and then formalize only later in the task when appropriate formalisms become clear and also (more) immediately useful.

It’s important to notice something about these examples of synthesis representations: they go quite a bit further than simply grouping or associating things (though that is an important start). They have some kind of formal semantic structure (otherwise known as formality) that specifies what entities exist, and what kinds of relations exist between the entities. This formal structure isn’t just for show: it’s what enables the kind of synthesis that really powers significant knowledge work! Formal structures unlock powerful forms of reasoning like conceptual combination, analogy, and causal reasoning.

Systems which display backlinks to a node permit a new behavior: you can define a new node extensionally (rather than intensionally) by simply linking to it from many other nodes—even before it has any content.

This is the real issue here, and it's a bug with chrome devtools, fixed in Chrome 46.

I think it would be much better to whitelist registries

The meaning of the word "modularity" can vary somewhat based on context. The following are contextual examples of modularity across several fields of science, technology, industry, and culture:

In Rust, we use the "No New Rationale" rule, which says that the decision to merge (or not merge) an RFC is based only on rationale that was presented and debated in public. This avoids accidents where the community feels blindsided by a decision.

I'd like to go with an RFC-based governance model (similar to Rust, Ember or Swift) that looks something like this: new features go through a public RFC that describes the motivation for the change, a detailed implementation description, a description on how to document or teach the change (for kpm, that would roughly be focused around how it affected the usual workflows), any drawbacks or alternatives, and any open questions that should be addressed before merging. the change is discussed until all of the relevant arguments have been debated and the arguments are starting to become repetitive (they "reach a steady state") the RFC goes into "final comment period", allowing people who weren't paying close attention to every proposal to have a chance to weigh in with new arguments. assuming no new arguments are presented, the RFC is merged by consensus of the core team and the feature is implemented. All changes, regardless of their source, go through this process, giving active community members who aren't on the core team an opportunity to participate directly in the future direction of the project. (both because of proposals they submit and ones from the core team that they contribute to)

If nobody objects or can come up with improvements, I'll approve.

And the App will be responsible for display a list of users adding/removing users of said list

e annotations are visible to everyone both in the document itself and our public stream. Privat

Tell you why tree-shaking fails, if it does.

What it doesn't do

We expect a certain pattern when validate devtool name, pay attention and dont mix up the sequence of devtool string. The pattern is: [inline-|hidden-|eval-][nosources-][cheap-[module-]]source-map.

I've only done components that need to/can be Svelte-ified. For some things, like RTL and layout grid, you can just use the MDC packages.

will only apply up the chain

Maybe it's also a bug because every warning should be ignorable? Not sure.

This is linux. Ouput first, formatting second. systemctl --no-pager -l should be the default.

Over 4 million people trust CloudApp

Retagging the HTML/CSS questions to use html-heading seems the right thing to do. For the other uses, I don't have enough grounding in the geographic area to know whether the direction and bearing are replacements for heading. But the tag information for heading should be created and should firmly point at the other tags — at least until it is expunged.

We could broadcast a warning if we find the variable to be set in the environment, but that is more likely than not to annoy people who intentionally set it.

If you have a better/simpler/"more official" solution, I'd still love to see it!

You may want to execute validations in a given specific order (this can be tricky especially when you have got asynchronous validations).

This is a philosophical issue, I think. People (and presumably form libraries) have different definitions of what "dirty" means. Yours: "The field has ever been edited" Mine: "The value of the field is different from the initial value"

We could potentially have another flag that was your definition of dirty, but then we run into the hard problem in computer science: naming things.

If that one somehow ends up being deemed an intended behavior rather than a bug, then it should definitely get explained in the docs too.

I'm not sure yet how much of this is a bug.

This isn't a bug. Svelte's reactivity is triggered by assignment, so it won't re-render on mutations like array pushing.

We want arr.push(foo); arr = arr; to work, and this is a bug.

Especially when rollup is configured with multiple outputs, I find this particular onwarn to be helpful in reducing warning clutter. It just displays each circular reference once and doesn't repeat the warning for each output:

I think my personal preference would be to see them all at once. Or maybe limit it to up to 10 messages and then list the count of how many more messages were not displayed. Pick your reaction

Another thing we could do to limit output would be to only every show the first circular dependency warning. I think we already do this for other types of warnings. Then you would need to tackle the warnings one-by-one, though.

Yeah I see what you're saying. In my case, I had a group of classes that relied on each other but they were all part of one conceptual "module" so I made a new file that imports and exposes all of them. In that new file I put the imports in the right order and made sure no code accesses the classes except through the new interface.

Doing so also means adding empty import statements to guarantee correct order of evaluation of modules (in ES modules, evaluation order is determined statically by the order of import declarations, whereas in CommonJS – and environments that simulate CommonJS by shipping a module loader, i.e. Browserify and Webpack – evaluation order is determined at runtime by the order in which require statements are encountered).

Specifically, since Root, Rule and AtRule all extend Container, it's essential that Container is evaluated (and therefore, in the context of a Rollup bundle, included) first. In order to do this, input.js (which is the 'gateway' to all the PostCSS stuff) must import root.js, root.js must import rule.js before it imports container.js, and rule.js must import at-rule.js before it imports container.js. Having those imports ensures that container.js doesn't then try to place Root, Rule or AtRule ahead of itself in the bundle.

Replaced nested `require` statements with `import` declarations for the sake of a leaner bundle. This entails adding empty imports to three files to guarantee correct ordering – see https://github.com/styled-components/styled-components/pull/100

Modules from the following layer can require anything from all the previous layers, but not vice versa.

Note that these are not hyperlinks; these URIs are used for identification. This is a machine-readable way to say “this is HTML”. In particular, software does not usually need to fetch these resources, and certainly does not need to fetch the same one over and over!

When communicating, being more specific is usually better, and a “URL” is a specific type of URI that provides an access method/location.

Every URL is a URI; Every URN is a URI; URI and URL are NOT interchangeable – a URL is a URI, but a URI is not always a URL; URLs always contain an access mechanism.

Note that the <WarningEngine/> component must be at the bottom of the form to guarantee that all the fields have registered.

Anyone who’s ever worked with me knows that I place a very high value on what ends up checked-in to a source code repository.

Of all the compile-to-languages, the one that strikes me as having the least merit is JSX. It's basically a ton of added complexity for the sake of what boils down to syntax. There are no real gains in terms of language semantics in JSX.

Yet it can be deceivingly difficult to properly encode (user) input

Encoding is dependent on the type of output - which means that for example a string, which will be used in a JavaScript variable, should be treated (encoded) differently than a string which will be used in plain HTML.

Escaping is a subset of encoding, where not all characters need to be encoded. Only some characters are encoded (by using an escape character).

Encoding is transforming data from one format into another format.

code is read much more often than it is written.

A style guide is about consistency. Consistency with this style guide is important. Consistency within a project is more important. Consistency within one module or function is the most important.

But the vast majority of things that our apps are doing are just conditional and list rendering.

More in-depth examples definitely sound like a good idea. I've seen cookbooks quite a few times already and they are always helpful.

When using TypeScript, cast the type of file.contents on your side.

object orientation

Disclaimer: I’m new to Svelte so this isn’t so much a recommendation as it is a “I guess this is a way to do it 🤷‍♂️”

JSX is an XML-like syntax extension to EcmaScript (https://facebook.github.io/jsx/). It is not a language or runtime.

helped me carve a niche for what would become SolidJS. I still see that space today, so I'm glad that I did.

There's one downside to Reacts reactivity model - the hooks (useState and useEffect) have to always be called in the same order and you can't put them inside an if block.

createState and createSignal are improvements over React's useState as it doesn't depend on the order of calls.

(Note sure if this is a feature request or a bug...)

Because I haven't worked with React Native, and so I'm not a specialist in it, and developing a React Native version of this package would better be done by someone being an expert in React Native.

perhaps, imo this would make more sense. but it would slow down Parcel significantly as packages who don't have a browserslist or something similar will all get compiled (and most packages actually do target commonjs, which makes this prob not such a good idea). Which unfortunately is way too many packages. It would be great if tools like babel actually enforced a similar pattern to Parcel and use browserlist file or package.json instead of allowing defining target env in babel. Or at least not encourage it.

Whilst

Ontologically

But we face our own hostile environment: underpowered devices, poor network connections, and the complexity inherent in front-end engineering.

I took the same approach with _layout.svelte and not just for the svelte-apollo client. Except I put all of that setup into another module (setup.js) and imported from _layout. I just couldn't stomach having all that code actually in my _layout file. It's for layout, supposedly, but it's the only component that is a parent to the whole app.

let:hovering={active}

let:active={hovering}

Getting the JS infrastructure upgraded can take hours of Googling.

But this is only a halfway decent way to clarify that this is an external dependency, because the only way to resolve a peer dependency warning is to install react from npm—there's no way to notify npm that you resolve the dependency to a browser global. So peer dependencies should be avoided in favor of external declarations. Then Rollup will take care of warning about "unresolved dependencies", even if external declarations can't express a particular version range with which your library is compatible like peer dependencies can.

If you've followed React's guide, you've installed react from npm. You can teach Rollup how to find this package within your project's node_modules directory using the rollup-plugin-node-resolve plugin. Since React exports a CommonJS module, you'll also need to convert that into an ES6 module using the rollup-plugin-commonjs plugin.

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.