Rookiepig @rookiepig - Tumblr Blog

Do not treat Vim as an IDE

One sentence from :help design-not

Vim is not a shell or an Operating System. You will not be able to run a shell inside Vim or use it to control a debugger. This should work the other way around: Use Vim as a component from a shell or in an IDE.

#vim linux

Rapid Environment Editor -- good software

Check environment vars are painful on windows. REE seems the best solution for this problem.

#software

Scholarpedia -- an interesting website

Scholarpedia is a website similar to wiki but more professional and instructive. However, its content is too little.

#memo

《一九八四》

乔治奥威尔

#novel

Vundle not Pathogen -- package manager for Vim

Both Vundle and Pathogen are meant to organise vim packages more elegantly. No need to manually maintain different plugins in the same vimfiles/ or .vim/ folder.

Though, most online tutorials for configuring vim plugins adopt Pathogen, I think Vundle is better. If you have tried Package Control for Sublime Text 2&3, you will find Vundle more friendly.

To use it across Windows and Linux, you need to slightly modify Vundle settings:

" set the runtime path to include Vundle and initialize " alternatively, pass a path where Vundle should install plugins " call vundle#begin('~/some/path/here') if (has('win16') || has('win32') || has('win64')) " Vundle for Windows set rtp+=$VIM/vimfiles/bundle/Vundle.vim let path='$VIM/vimfiles/bundle' call vundle#begin(path) elseif (has('unix') && !has('macunix') && !has('win32unix')) " Vundle for Unix set rtp+=~/.vim/bundle/Vundle.vim call vundle#begin() endif

#vim

About vimrc

Don't put anything in your .vimrc you don't understand!

-- Doug Black

Aha, a joke heard from another guy's blog

If Richard Stallman, the original author of Emacs, is hit by a bus, Emacs will be almost completely unaffected. Other people have the source code and will continue updating Emacs. If Jon Skinner, the author of Sublime Text, is hit by a bus, all development on Sublime Text may stop.

:)

#sublime text #emacs

gflags on windows

See below code from gflags.cc

PathMatchSpec(glob.c_str(), ProgramInvocationName()) ...

Thus, on windows, gflags use function PathMatchSpec, which needs to link Shiwapi.lib.

#technique #gflags

Python -- Multidimensional array and "for" loop

Multidimensional array and Comprehensions

List stores ordered data and it is heterogenous (different datatypes in one list). So python does not support explicitly multidimensional array but you can nest list to get multidimensional array. For example:

a = [[1, 2], [3,4]] a = [[[1, 2] [3, 4]], [[5, 6], [7, 8]]

To store data in a list, one possible method is to use the append() method of list object:

someList = [] for i in range(10) : someList.append(i)

However, this will become more complicated when handling multidimensional array. Can we use some compact method to initialise a multidimensional array such as int a[10][10] in C/C++? The answer is yes by using Comprehensions.

Comprehension can be thought as a compact for loop. A list comprehension goes like:

[expression for variable in list]

To create a list, we can write:

someList = [0 for i in range(10)]

more powerful usage is:

someList = [i * i for i in range(10)]

Then, for multidimensional array, it goes like:

someList = [[i + j for j in range(n)] for i in range(m)]

which is an m * n matrix and can be accesed by:

someList[m - 1][n - 1]

For loop

Unlike C/C++, python's for loop just iterates over the items of any sequence (strings, Unicode strings, lists, tuples, bytearrays, buffers, and xrange objects.). A simple example:

animals = ['cat', 'dog', 'bird'] for a in animals : print a

In python, for can be used with else:

for x in range(5) : print x else : print 'Final x = %d' % (x)

Note that statements in else block will not excute if the for loop exists by break statement.

Ref

Arrarys in Python

Python Doc for statements

Python Wiki for loops

#technique #python

New Features of C++

Recently, learn some new features of C++. I have to say: WOW! I think most of them come from C++ 11:

auto -- let the compiler infer the type:

auto a = 1; auto b = 1.0; cout << "a type: " << typeid(a).name() << endl; cout <, "b type: " << typeid(b).name() << endl;

retrailing return type -- useful for templates:

template<class Type1 class Type2> auto add( Type1 a, Type2, b ) -> decltype(a+b) { return a + b; }

another nightmare example come from here:

template <class T> class tmp { public: int i; }; tmp<int> (*(*foo())())() { return 0; }

can be much more readable as:

template <class T> class tmp { public: int i; }; auto foo()->auto(*)()->tmp<int>(*)() { return 0; }

lambda function -- functional programming:

auto lambda = [] () { cout << "hello\n"; };

move constructor -- STL vector seems too slow, thus if you do not know the implementation of STL, be careful when using them.

MSDN move constructor example

rvalue reference declarator -- move constructor benefits from this:

// one example class A: void func( A&& a ) { ... }; func( A() ); // another example int f_lvalue_ref( int& a ) { ... }; int f_rvalue_ref( int&& a ) { ... }; f_lvalue_ref( 1 ); // error! f_rvalue_ref( 1 ); // OK

#technique #cpp