Jiahao XU NobodyXu

Semantics:
- assignment:
  - When assigning a variable to another name, eg, a = b, a new object is created. However, no data is copied due to the [copy-on-modify][ref1]
- In order to xor booleans, use xor(a, b).
- reminder and quotient
  - %% for reminder and %/% for quotient.
- For accessing list inside list, [[index]] must be used.
- For returning a vector from a data.frame or data.table, df[[one_list_index]] must be used.
- slicing:
Slicing happens when you [] a container (vector, list, etc) using more than one index, generated by seq or : or c(). The index used can be integers or charaters.

tree: Display directory and its child dir (can be controlled via -L level) in tree.

cygwin/x

First, install cygwin/x. If no mirror are found, google 'cygwin/x mirrors' and you shall find many. Make sure xorg is always installed. Then, open "XWin server" file location from start menu, add -- -listen tcp to the end of target.

WSL

Install cygwin/x

See here

Putty

Install putty, and then enter your virtual machine's IP, then go to Connection->ssh->X11, click Enable X11 forwarding and give the Xauthority file C:\Cygwin64\C:\cygwin64\home\${YOUR_USERNAME_HERE}\.Xauthority. Save the session with your favorite name to reuse the session.

Setup multiple git identities & git user informations

/!\ Be very carrefull in your setup : any misconfiguration make all the git config to fail silently ! Go trought this guide step by step and it should be fine 😉

Setup multiple git ssh identities for git

Generate your SSH keys as per your git provider documentation.
Add each public SSH keys to your git providers acounts.
In your ~/.ssh/config, set each ssh key for each repository as in this exemple:

	#!/usr/bin/env python3

	import sys

	# rowList is a list who the first and last element is 0(which will not be printed)
	def print_pascal_triangle_row(row):
	print(" ".join([str(each) for each in row[1 : -1]]))

	# @parm n denotes how many rows should it print
	def print_pascal_triangle(n):

	#!/usr/bin/env perl

	# This short script queries the icecream scheduler to discover what machines are connected,
	# and sums the maximum job counts for all x86-64 machines.
	# It can be used in your mozconfig as follows:
	# mk_add_options MOZ_MAKE_FLAGS="-j$(icecc-jobs)"
	# if this script is on your PATH, and named icecc-jobs

	use List::Util qw(sum0);

	use core::ffi::c_void;
	use core::mem::transmute;
	use core::ptr::null_mut;
	use core::marker::PhantomData;

	/// ErasedFnPointer can either points to a free function or associated one that
	/// `&mut self`
	struct ErasedFnPointer<'a, T, Ret> {
	struct_pointer: *mut c_void,
	fp: *const (),

	ssize_t read(int fd, void *buf, size_t count);

	ssize_t write(int fd, const void *buf, size_t count);