semantics

Specification for a Functional Reactive Programming language

由 为君一笑 提交于 2019-11-26 18:42:30
问题 I am looking at messing around with creating a functional reactive framework at some point. I have read quite a lot about it and seen a few examples but I wanted to get a clear idea of what this framework would HAVE to do to be considered an FRP extension/dsl. I'm not really concerned with implementation problems or specifics etc but more as to what would be desired in a perfect world situation. What would be the key operations and qualities of an ideal functional reactive programming

How to properly use h1 in HTML5

由 和自甴很熟 提交于 2019-11-26 17:58:19
问题 Which of the following is the correct way to structure a page: 1) h1 only in header <header> <h1>Site title</h1> <nav>...</nav> </header> <section> <h2>Page title</h2> </section> If I use h1 exclusively inside header as the site's title, every page will have the same content for the h1 tag. That doesn't seem very informative. 2) h1 in header and section , for both site and page title <header> <h1>Site title</h1> <nav>...</nav> </header> <section> <h1>Page title</h1> </section> I've also seen

Why would R use the “L” suffix to denote an integer?

由 半世苍凉 提交于 2019-11-26 17:49:48
问题 In R we all know it is convenient for those times we want to ensure we are dealing with an integer to specify it using the "L" suffix like this: 1L # [1] 1 If we don't explicitly tell R we want an integer it will assume we meant to use a numeric data type... str( 1 * 1 ) # num 1 str( 1L * 1L ) # int 1 Why is "L" the preferred suffix, why not "I" for instance? Is there a historical reason? In addition, why does R allow me to do (with warnings): str(1.0L) # int 1 # Warning message: # integer

boost spirit semantic action parameters

由 只愿长相守 提交于 2019-11-26 17:15:46
in this article about boost spirit semantic actions it is mentioned that There are actually 2 more arguments being passed: the parser context and a reference to a boolean ‘hit’ parameter. The parser context is meaningful only if the semantic action is attached somewhere to the right hand side of a rule. We will see more information about this shortly. The boolean value can be set to false inside the semantic action invalidates the match in retrospective, making the parser fail. All fine, but i've been trying to find an example passing a function object as semantic action that uses the other

HTML5 nested sections and heading tags

由 こ雲淡風輕ζ 提交于 2019-11-26 16:44:00
I have section tags nested underneath another section tag. Is it okay to have start the headings from 1 again? For example: <section> <h1>Page Title</h1> <section> <h1>Section Title</h1> <h2>Section Sub Title</h2> <p>Sub section text</p> </section> <section> <h1>Section Title</h1> <h2>Section Sub Title</h2> <p>Sub section text</p> </section> </section> Thanks, Mark unor Yes, it’s valid. However, HTML5 encourages to use […] headings of the appropriate rank for the section's nesting level. But it’s not a requirement, so you are free to choose. Using h1 everywhere allows for moving sections

When is a language considered a scripting language? [closed]

由 徘徊边缘 提交于 2019-11-26 14:51:28
What makes a language a scripting language? I've heard some people say "when it gets interpreted instead of compiled". That would make PHP (for example) a scripting language. Is that the only criterion? Or are there other criteria? See also: What’s the difference between a “script” and an “application”? A scripting language is a language that "scripts" other things to do stuff. The primary focus isn't primarily building your own apps so much as getting an existing app to act the way you want, e.g. JavaScript for browsers, VBA for MS Office. Martin Beckett Simple. When I use it, it's a modern

GET vs POST in Ajax

由 牧云@^-^@ 提交于 2019-11-26 12:44:13
What is the difference between GET and POST for Ajax requests? I don't see any difference between those two, except that when I use GET , the parameters are send in URL, which for me don't really make any difference, since all requests are made on background and user doesn't find any difference. edit: What are PUT and DELETE methods used for? crb GET is designed for getting data from the server. POST (and lesser-known friends PUT and DELETE) are designed for modifying data on the server. A GET request should never cause data to be removed from an application. If you have a link you can click

Semantically, which is more correct: a in h2, or h2 in a?

由 我的梦境 提交于 2019-11-26 12:43:42
问题 I\'m stuck deciding which to use as both seem to work. Should I be placing links <a> inside of <h2> elements? Or the other way around? What is the correct standard? 回答1: You can only place <h2> elements within <a> elements if you're working with HTML5, which allows any other elements within <a> elements. Previous specifications (or current ones however you want to look at them) never allowed this. The usual way of doing this is to place <a> within <h2> . This works, has always worked, and has

Finding the id of a parent div using Jquery

由 你。 提交于 2019-11-26 12:35:59
问题 I have some html like this: <div id=\"1\"> <p> Volume = <input type=\"text\" /> <button rel=\"3.93e-6\" class=\"1\" type=\"button\">Check answer</button> </p> <div></div> </div> and some JS like this: $(\"button\").click(function () { var buttonNo = $(this).attr(\'class\'); var correct = Number($(this).attr(\'rel\')); validate (Number($(\"#\"+buttonNo+\" input\").val()),correct); $(\"#\"+buttonNo+\" div\").html(feedback); }); What I\'d really like is if I didn\'t have to have the class=\"1\"

boolean in an if statement

由 此生再无相见时 提交于 2019-11-26 10:07:55
问题 Today I\'ve gotten a remark about code considering the way I check whether a variable is true or false in a school assignment. The code which I had written was something like this: var booleanValue = true; function someFunction(){ if(booleanValue === true){ return \"something\"; } } They said it was better/neater to write it like this: var booleanValue = true; function someFunction(){ if(booleanValue){ return \"something\"; } } The remark which I have gotten about the \"=== true\" part was
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