notation

Scala - Prefix Unary Operators

由 假如想象 提交于 2019-12-06 19:50:45
问题 I've recently given Scala a second chance, and started with the project I always implement (in functional or pseudo-functional languages): an automated reasoner for propositional logic (and later predicate logic). Now, I've tried to get the notation of propositional logic in the language itself as pretty as possible, and I've gotten this far - with an implicit conversion (String -> Atom): ("A" and "B") implies "C" The functions "and" and "implies" (and "or" and "equivalent") are simple

What is the difference between “std::string const &s” and “const std::string &s”?

由 牧云@^-^@ 提交于 2019-12-06 18:07:44
问题 I was looking for examples on how to do something and saw this two variants: std::string const &s; const std::string &s; in different snippets. thx for your answer :) 回答1: std::string const & is equivalent to const std::string & . const std::string & is the style adopted in Stroustrup's The C++ Programming Language and probably is "the traditional style". std::string const & can be more consistent than the alternative: the const-on-the-right style always puts the const on the right of what it

A productive alternative to UML

由 吃可爱长大的小学妹 提交于 2019-12-06 03:11:12
问题 I find UML hard to create quickly. I'd like to put my ideas more quickly, especially for small open sourced projects. If it was big enough I'd bother with UML but the project is too small for this kind of thing. I don't want yet another tool that will make me think "nehh I'll do it later". Any suggestions? 回答1: You could use a blog (WordPress is quick) or a mind map (here's one free on Sourceforge) 回答2: UML is not a tool, it's a language. If you want a tool that is quick and easy, I'd

Lua: colon notation, 'self' and function definition vs. call

由 我们两清 提交于 2019-12-05 12:47:50
I'm getting terribly confused by the colon notation used when defining/calling Lua functions. I thought I'd got my head round it until I saw this piece of code: function string.PatternSafe( str ) return ( str:gsub( ".", pattern_escape_replacements ) ); end function string.Trim( s, char ) if char then char = char:PatternSafe() else char = "%s" end return string.match( s, "^" .. char .. "*(.-)" .. char .. "*$" ) or s end What's confusing me here is that string.PatternSafe() doesn't reference 'self' anywhere, yet the code seems to work. I've also seen some scripts that use colon notation when

iOS First Application “self.userName = textField.text”. When to use self

由 坚强是说给别人听的谎言 提交于 2019-12-05 10:00:42
问题 Here is a code snippet from Apple's "Your First iOS Application" document. - (IBAction)changeGreeting:(id)sender { self.userName = textField.text; NSString *nameString = self.userName; if ([nameString length] == 0) { nameString = @"World"; } NSString *greeting = [[NSString alloc] initWithFormat:@"Hello, %@!", nameString]; label.text = greeting; [greeting release]; } I understand that self.username calls the synthesized set method (important since it has a copy flag). Why is textField.text and

How to remove scientific notation on a matplotlib log-log plot

由 泄露秘密 提交于 2019-12-05 01:15:37
I know that this question has been asked before, but I tried all the possible solutions and none of them worked for me. So, I have a log-log plot in matplotlib, and I would like to avoid scientific notation on the x-axis. This is my code: from numpy import array, log, pi import matplotlib.pyplot as plt from scipy.optimize import curve_fit import matplotlib.ticker as mticker plt.rc('axes.formatter', useoffset=False) tc = array([7499680.0, 12508380.0, 23858280.0, 34877020.0, 53970660.0, 89248580.0, 161032860.0, 326814160.0, 784460200.0]) theta = array([70, 60, 50, 45, 40, 35, 30, 25, 20]) plt

Muscial notation on the iPhone. Any suggestions for example code? [closed]

由 不打扰是莪最后的温柔 提交于 2019-12-04 20:41:12
问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 11 months ago . I'm writing an iPhone app where I'd like to display some simple musical notation (just a chord or two). This question is a call for suggestions on the quickest way to go about it. For instance: Is there any iphone OR objective-C libraries for doing this that I'm missing? Are

ɵ (Theta-like) symbol in Angular 2+ source code

由 纵饮孤独 提交于 2019-12-04 15:37:20
问题 After a deep dive into an Angular 4.3.* source code I was bumping into ɵ symbol quite often. For example, in async pipe source we see the usage of ɵisPromise(_) and ɵisObservable(_) functions. So now I wonder why Angular team decided to use it? And what does it mean? It seems that Angular devs mark methods/modules with ɵ to emphasize they are some kind of inner entities that should never be imported. But I didn`t find any authoritative proofs. After some deeper research I found another

Syntax for documenting JSON structure

由 怎甘沉沦 提交于 2019-12-04 07:47:32
问题 So I'm trying to document the format of the json returned by an api I am writing against and I'd like to know if there is any popular format for the documentation of json structure. Note I'm not trying to to test or validate anything, I'm just using this for documentation. Also some ways to add comments to non-constants(items always returned w/ the same value) would be nice. This the not totally thought out scheme I'm currently using: Plain names refer to identifiers or types. Some types have

python SyntaxError with dict(1=…), but {1:…} works

由 旧城冷巷雨未停 提交于 2019-12-04 03:05:20
Python seems to have an inconsistency in what kind of keys it will accept for dicts. Or, put another way, it allows certain kinds of keys in one way of defining dicts, but not in others: >>> d = {1:"one",2:2} >>> d[1] 'one' >>> e = dict(1="one",2=2) File "<stdin>", line 1 SyntaxError: keyword can't be an expression Is the {...} notation more fundamental, and dict(...) just syntactic sugar? Is it because there is simply no way for Python to parse dict(1="one") ? I'm curious... This is not a dict issue, but an artifact of Python syntax: keyword arguments must be valid identifiers, and 1 and 2
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