symbols

It's well known to Rubyist & will call to_proc on a symbol, so [:a, :b, :c].map(&:to_s) is equivalent to [:a, :b, :c].map { |e| e.to_s } # => ["a", "b", "c"] Say I want to call another method right after to_s , these two implementations will work: [:a, :b, :c].map { |e| e.to_s.upcase } [:a, :b, :c].map(&:to_s).map(&:upcase) My question is, is there a way to chain the & Symbol#to_proc call in one parameter? Something like: [:a, :b, :c].map(&:to_s:upcase) Thanks! If you're only doing: %i[a b c].map { |e| e.to_s.upcase } then just use the block and get on with more important things. If you're

How to store symbol for Euro currency in MySQL Database ? Create a column with a character set that supports the Euro character. CREATE TABLE MyTable ( MyEuroColumn VARCHAR(5) CHARACTER SET utf8 COLLATE utf8_general_ci ); If your editor doesn't support Unicde, you can insert it like; select concat('Five ', _ucs2 0x20AC, ' please!') You can also store the Euro symbol in other character sets : UTF-8 0xE282AC UCS-16 0x20AC ISO-8859-15 (latin-9) 0xA4 If the table or the column is set to use utf8 encoding, something like this works fine: insert into test values (1, '€ <- euro'); Also, add this to

When I first started reading about and learning ruby, I read something about the power of ruby symbols over strings: symbols are stored in memory only once, while strings are stored in memory once per string, even if they are the same. For instance: Rails' params Hash in the Controller has a bunch of keys as symbols: params[:id] or params[:title]... But other decently sized projects such as Sinatra and Jekyll don't do that: Jekyll: post.data["title"] or post.data["tags"]... Sinatra: params["id"] or params["title"]... This makes reading new code a little tricky, and makes it hard to transfer

I thought ifndef something #define something body #endif solved this error, so I'm not sure why this is happening. //Library.h #ifndef __LIBRARY__ #define __LIBRARY__ #include <iostream> #include <string> #include <cstring> #include <cmath> #include <cstdio> #include <cstdarg> #include <vector> #include <ctime> #include <cmath> #include <cstdlib> //file includes #include "Globals.h" using namespace std; #endif //__LIBRARY__ -- //globals.h //global variables #ifndef __GLOBAL__ #define __GLOBAL__ #include <vector> #include <iostream> #include <string> //prototypes bool Poglathon(std::vector<std:

I'm in the process of learning Clojure and I can't understand some language design decisions: Why does a language with immutable Strings like Clojure also needs Keywords and Symbols data types? Couldn't strings just have optional namespaces and metadata and all this stuff? For immutable strings comparison could just as well be identity base, no? Or, since interop with Java is a must have for Clojure, at least have the Java String type and a KeywordSymbol data type. I find this String/Keyword/Symbol "trichotomy" especially weird since Clojure seems very focused on "purity" and keeping things

Here is the error message I receive when compiling ... Ld /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Products/Debug-iphonesimulator/MasterDetail.app/MasterDetail normal i386 cd /Users/ilia3546/Проекты/iDecide setenv IPHONEOS_DEPLOYMENT_TARGET 5.0 setenv PATH "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin" /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch i386

Is there a Python equivalent to Ruby symbols? If so then what is it? If not then are we stuck with using strings as our keys in dictionaries only? sepp2k No, python doesn't have a symbol type. However string literals are interned by default and other strings can be interned using the intern function. So using string literals as keys in dictionaries is not less performant than using symbols in ruby. As others have said, there is no symbol in Python, but strings work well. To avoid quoting strings as keys, use the dict() constructor syntax: d = dict( a = 1, b = 2, c = "Hello there", ) Also for

Last week I released the Linux and windows version of an application. And after the release we realized that the symbols were not stripped off, and my manager thinks (and I disagree) that it might allow the user to understand our algorithm. Anyway, now, I will have to clean-up the symbols and re-release the application. My question, What is the best way to strip symbols in Linux? What is the best way to strip symbols in Windows? With Visual C++ (and other Microsoft compilers) on Windows, symbols aren't part of the binaries. Instead, they are stored in separate files called "Program Database"

I am coding a function that solves an arbitrary number of simultaneous equations. The number of equations is set by one of the parameters of the function and each equation is built from a number of symbols - as many symbols as there are equations. This means that I can't simply hardcode the equations, or even the symbols needed to put together the equations; the function needs to be able to handle any number of equations. So, my question is, how do I produce a list of symbols? I have one possible solution, but my gut tells me that it's not going to be very efficient. Please let me know if