Tutorial by Examples: r

Import an HTML file that will add a div with "Hello, World!" at the end of the main document's DOM tree. Imported file hello.html: <script> var div = document.createElement( 'div' ) div.innerHTML = 'Hello, World!' document.body.appendChild( div ) </script> Mai...

This example combines Custom Element, Template, Shadow DOM and HTML Import to display a the "Hello, World!" string in HTML. In file hello-world.html: <!-- 1. Define the template --> <template> Hello, World! </template> <script> var template = document....

In lua, the logical operators and and or returns one of the operands as the result instead of a boolean result. As a consequence, this mechanism can be exploited to emulate the behavior of the ternary operator despite lua not having a 'real' ternary operator in the language. Syntax condition and...

NSMutableArray *array = [NSMutableArray arrayWithObjects:@"Ken", @"Tim", @"Chris", @"Steve",@"Charlie",@"Melissa", nil]; NSPredicate *bPredicate = [NSPredicate predicateWithFormat:@"SELF beginswith[c] 'c'"]; NSArray ...

String and character literals provide an escape mechanism that allows express character codes that would otherwise not be allowed in the literal. An escape sequence consists of a backslash character (\) followed by one ore more other characters. The same sequences are valid in both character an st...

Read the documentation in this order to easily learn postscript: Paul Bourke's excellent tutorial: http://paulbourke.net/dataformats/postscript/ Blue Book, first half, the original official tutorial: http://www-cdf.fnal.gov/offline/PostScript/BLUEBOOK.PDF Green Book, how to use posts...

#import <Foundation/Foundation.h> int main() { NSLog(@"File :%s\n", __FILE__ ); NSLog(@"Date :%s\n", __DATE__ ); NSLog(@"Time :%s\n", __TIME__ ); NSLog(@"Line :%d\n", __LINE__ ); NSLog(@"ANSI :%d\n", __STDC__ ); ...

Given data Empty a we have data Free Empty a = Pure a -- the Free constructor is impossible! which is isomorphic to data Identity a = Identity a

Given data Identity a = Identity a we have data Free Identity a = Pure a | Free (Identity (Free Identity a)) which is isomorphic to data Deferred a = Now a | Later (Deferred a) or equivalently (if you promise to evaluate the fst element first) (Nat, a), aka Writer...

Given data Maybe a = Just a | Nothing we have data Free Maybe a = Pure a | Free (Just (Free Maybe a)) | Free Nothing which is equivalent to data Hopes a = Confirmed a | Possible (Hopes a) | Failed or equivalently (if you promise to evalua...

Given data Writer w a = Writer w a we have data Free (Writer w) a = Pure a | Free (Writer w (Free (Writer w) a)) which is isomorphic to data ProgLog w a = Done a | After w (ProgLog w a) or, equivalently, (if you promise to evaluate the log first), Writer [w] a. ...

Given data Const c a = Const c we have data Free (Const c) a = Pure a | Free (Const c) which is isomorphic to data Either c a = Right a | Left c

Given data Reader x a = Reader (x -> a) we have data Free (Reader x) a = Pure a | Free (x -> Free (Reader x) a) which is isomorphic to data Demand x a = Satisfied a | Hungry (x -> Demand x a) or equivalently Stream x -> a with data Stream x = Stream x...

Given data Empty a we have data Cofree Empty a -- = a :< ... not possible!

Given data Const c a = Const c we have data Cofree (Const c) a = a :< Const c which is isomorphic to data Writer c a = Writer c a

Given data Identity a = Identity a we have data Cofree Identity a = a :< Identity (Cofree Identity a) which is isomorphic to data Stream a = Stream a (Stream a)

Given data Maybe a = Just a | Nothing we have data Cofree Maybe a = a :< Just (Cofree Maybe a) | a :< Nothing which is isomorphic to data NonEmpty a = NECons a (NonEmpty a) | NESingle a

Given data Writer w a = Writer w a we have data Cofree (Writer w) a = a :< (w, Cofree (Writer w) a) which is equivalent to data Stream (w,a) = Stream (w,a) (Stream (w,a)) which can properly be written as WriterT w Stream with data WriterT w m a = WriterT (m (w,a))

Given data Either e a = Left e | Right a we have data Cofree (Either e) a = a :< Left e | a :< Right (Cofree (Either e) a) which is isomorphic to data Hospitable e a = Sorry_AllIHaveIsThis_Here'sWhy a e | EatThis a (Hospitable e a) or, if yo...

Given data Reader x a = Reader (x -> a) we have data Cofree (Reader x) a = a :< (x -> Cofree (Reader x) a) which is isomorphic to data Plant x a = Plant a (x -> Plant x a) aka Moore machine.