Tutorial by Examples: t

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...

The size of the content will be the same as that of its ScrollPane container. import javafx.scene.control.ScrollPane; //Import the ScrollPane import javafx.scene.control.ScrollPane.ScrollBarPolicy; //Import the ScrollBarPolicy import javafx.scene.layout.Pane; ScrollPane scrollpane; Pane con...

The size of the content will change depending on the added elements that exceed the content limits in both axes (horizontal and vertical) that can be seen by moving through the view. import javafx.scene.control.ScrollPane; //Import the ScrollPane import javafx.scene.control.ScrollPane.ScrollBar...

The appearance of the ScrollPane can be easily changed, by having some notions of "CSS" and respecting some control "properties" and of course having some "imagination". A) The elements that make up ScrollPane : B) CSS properties : .scroll-bar:vertical .track{} ...

Xcode have ability to run any script with hotkey. Here is example how to assign hotkey ⌘+⌥+⌃+⇧+T to open Terminal app in current project folder. Create bash script and save it in some folder #!/bin/bash # Project Name: $XcodeProject # Project Dir: $XcodeProjectPath # Workspace Dir: $X...

Data is usually perceived as something static that is entered into a database and later queried. But in many environments, data is actually more similar to a product in an assembly line, moving from one environment to another and undergoing transformations along the way. ■ OLTP: online transactio...

While developing, inserting the following line to your code: assert False, value will cause django to raise an AssertionError with the value supplied as an error message when this line is executed. If this occurs in a view, or in any code called from a view, and DEBUG=True is set, a full and de...

Debugging takes time and effort. Instead of chasing bugs with a debugger, consider spending more time on making your code better by: Write and run Tests. Python and Django have great builtin testing frameworks - that can be used to test your code much faster than manually with a debugger. Writ...

To display current version, we can use VERSION from @angular/core package. import { Component, VERSION } from '@angular/core'; @Component({ selector: 'my-app', template: `<h1>Hello {{name}}</h1> <h2>Current Version: {{ver}}</h2> `, }) export class AppCompone...

Binary Literals: The integral types (byte, short, int, and long) can also be expressed using the binary number system. To specify a binary literal, add the prefix 0b or 0B to the number. Strings in switch Statements: You can use a String object in the expression of a switch statement The try-wit...