Tutorial by Examples: re

proc myproc {alpha beta} { ... set foo $alpha set beta $bar ;# note: possibly useless invocation } myproc 12 34 ;# alpha will be 12, beta will be 34 If the argument list consists of words, those will be the names of local variables in the procedure, and their initi...

### Definition proc myproc {alpha {beta {}} {gamma green}} { puts [list $alpha $beta $gamma] } ### Use myproc A # => A {} green myproc A B # => A B green myproc A B C # => A B C This procedure accepts one, two, or three arguments: those parameters whose names are the fi...

proc myproc args { ... } proc myproc {args} { ... } ;# equivalent If the special parameter name args is the last item in the argument list, it receives a list of all arguments at that point in the command line. If there are none, the list is empty. There can be arguments, including optional one...

proc myproc {varName alpha beta} { upvar 1 $varName var set var [expr {$var * $alpha + $beta}] } set foo 1 myproc foo 10 5 puts $foo # => 15 In this particular case, the procedure is given the name of a variable in the current scope. Inside a Tcl procedure, such variables aren't...

# application.rb config.time_zone = 'Eastern Time (US & Canada)'

# application.rb config.time_zone = 'Eastern Time (US & Canada)' config.active_record.default_timezone = :local

N-bit deep shift register with asynchronous reset. module shift_register #( parameter REG_DEPTH = 16 )( input clk, //clock signal input ena, //enable signal input rst, //reset signal input data_in, //input bit output data_out //output bit ); reg [REG_DE...

If you are optimizing all images manually, disable APT Cruncher for a smaller APK file size. android { aaptOptions { cruncherEnabled = false } }

The GetParentFolderName method returns the parent folder for any path. While this can also be used with folders, it is arguably more useful for extracting the path from an absolute file path: Dim fso As New Scripting.FileSystemObject Debug.Print fso.GetParentFolderName("C:\Users\Me\My Docume...

In some cases it is necessary to calculate a variable amount of values on separate Futures. Assume to have a List[Future[Int]], but instead a List[Int] needs to be processed. Then the question is how to turn this instance of List[Future[Int]] into a Future[List[Int]]. For this purpose there is the s...

Keeping a GUI responsive while running a lengthy process requires either some very elaborate "callbacks" to allow the GUI to process its message queue, or the use of (background) (worker) threads. Kicking off any number of threads to do some work usually isn't a problem. The fun starts wh...

Following example shows steps involved in initializing a view from XIB. This is not a complex operation but exact steps need to be followed in order to do it right way first time, avoiding exceptions. How does loadNibNamed Works Main steps are: Create XIB Create class .h and .m Define outlet...

The appcache will cause some confusion in your development workflow, because it hides Meteor's auto-updating features. When you turn off the server component of your app, the client portion in your browser will continue working. This is a good thing! But, you don't get the immediate feedback that ...

If you're running a replica set or have a need to shard your database, you'll want an upstart script that looks something like this: # /etc/init/myapp.conf description "myapp.mydomain.com" author "[email protected]" # used to be: start on startup # until we found som...

You'll need to add debugger statements to your code: Meteor.methods({ doSomethingUself: function(){ debugger; niftyFunction(); } });

Ensure that you install the correct npm dependencies (babel decided to split itself into a bunch of packages, something to do with "peer dependencies"): npm install webpack webpack-node-externals babel-core babel-loader babel-preset-react babel-preset-latest --save webpack.config.js: mo...

This is very common, you memorize a path to a file or folder, you open up Vim and try to write what you've just memorized, but you are not 100% sure it's correct, so you close the editor and start over. When you want the path completion feature, and you have a file /home/ubuntu/my_folder/my_file a...

To delete some lines of text when you don't know exact number of lines to delete, you try 10dd , 5dd , 3dd until you remove all the lines. Relative line numbers solves this problem, suppose we have a file containing : sometimes, you see a block of text. You want to remove it but you cannot d...

In the following command the range starts 6 lines above the current line and ends 3 lines below: :-6,+3command

:s/foo/bar Replace the first instance of foo with bar on the current line. :s/foo/bar/g Replace every instance of foo with bar on the current line. :%s/foo/bar/g Replace foo with bar throughout the entire file.