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Modules can be used to add new functions to existing Modules and Types. namespace FSharp.Collections module List = let pair item1 item2 = [ item1; item2 ] The new function can then be called as if it was an original member of List. open FSharp.Collections module Testing = le...

[<Measure>] type m // meters [<Measure>] type cm // centimeters // Conversion factor let cmInM = 100<cm/m> let distanceInM = 1<m> let distanceInCM = distanceInM * cmInM // 100<cm> // Conversion function let cmToM (x : int<cm>) = x / 100<cm/m> l...

A component is some sort of user interface element, such as a button or a text field. Creating a Component Creating components is near identical to creating a window. Instead of creating a JFrame however, you create that component. For example, to create a JButton, you do the following. JButton b...

Components have various parameters that can be set for them. They vary from component to component, so a good way to see what parameters can be set for components is to start typing componentName.set, and let your IDE's autocomplete (If you use an IDE) suggest methods. The default shortcut in many I...

DescriptionClassButtonJButtonCheckboxJCheckBoxDrop down menu / Combo boxJComboBoxLabelJLabelListJListMenu barJMenuBarMenu in a menu barJMenuItem in a menuJMenuItemPanelJPanelProgress barJProgressBarRadio buttonJRadioButtonScroll barJScrollBarSliderJSliderSpinner / Number pickerJSpinnerTableJTableTre...

The following examples show 3 main methods for installing Erlang/OTP on FreeBSD. Method 1 - Pre-built Binary Package Use pkg to install the pre-built binary package: $ pkg install erlang Test your new installation: $ erl Erlang/OTP 18 [erts-7.3.1] [source] [64-bit] [smp:2:2] [async-threads:1...

You can build a JSON object tree (a JsValue) manually import play.api.libs.json._ val json = JsObject(Map( "name" -> JsString("Jsony McJsonface"), "age" -> JsNumber(18), "hobbies" -> JsArray(Seq( JsString("Fishing"), ...

Catamorphisms, or folds, model primitive recursion. cata tears down a fixpoint layer by layer, using an algebra function (or folding function) to process each layer. cata requires a Functor instance for the template type f. cata :: Functor f => (f a -> a) -> Fix f -> a cata f = f . fma...

Anamorphisms, or unfolds, model primitive corecursion. ana builds up a fixpoint layer by layer, using a coalgebra function (or unfolding function) to produce each new layer. ana requires a Functor instance for the template type f. ana :: Functor f => (a -> f a) -> a -> Fix f ana f = Fi...

CREATE TABLE table_name ( id INT NOT NULL AUTO_INCREMENT, json_col JSON, PRIMARY KEY(id) );

INSERT INTO table_name (json_col) VALUES ('{"City": "Galle", "Description": "Best damn city in the world"}'); That's simple as it can get but note that because JSON dictionary keys have to be surrounded by double quotes the entire thing should b...

Cryptography is something very hard and after spending a lot of time reading different examples and seeing how easy it is to introduce some form of vulnerability I found an answer originally written by @jbtule that I think is very good. Enjoy reading: "The general best practice for symmetric e...

The List API has eight methods for positional access operations: add(T type) add(int index, T type) remove(Object o) remove(int index) get(int index) set(int index, E element) int indexOf(Object o) int lastIndexOf(Object o) So, if we have a List: List<String> strings = new ArrayL...

#include <iostream> long double operator"" _km(long double val) { return val * 1000.0; } long double operator"" _mi(long double val) { return val * 1609.344; } int main() { std::cout << "3 km = " << 3.0_km << " m...

Batch execution using java.sql.PreparedStatement allows you to execute a single DML statement with multiple sets of values for its parameters. This example demonstrates how to prepare an insert statement and use it to insert multiple rows in a batch. Connection connection = ...; // obtained earl...

Batch execution using java.sql.Statement allows you to execute multiple DML statements (update, insert, delete) at once. This is achieved by creating a single statement object, adding the statements to execute, and then execute the batch as one. Connection connection = ...; // obtained earlier c...

Compare the definition of Free to that of Fix: data Free f a = Return a | Free (f (Free f a)) newtype Fix f = Fix { unFix :: f (Fix f) } In particular, compare the type of the Free constructor with the type of the Fix constructor. Free layers up a functor just like Fix, except ...

options = { "x": ["a", "b"], "y": [10, 20, 30] } Given a dictionary such as the one shown above, where there is a list representing a set of values to explore for the corresponding key. Suppose you want to explore "x"="a" w...

If you use a dictionary as an iterator (e.g. in a for statement), it traverses the keys of the dictionary. For example: d = {'a': 1, 'b': 2, 'c':3} for key in d: print(key, d[key]) # c 3 # b 2 # a 1 The same is true when used in a comprehension print([key for key in d]) # ['c', 'b', '...

Throughout this example it is assumed that the 'root' object that is being serialized to JSON is an instance of the following class : public class MyJson { }   Example 1 : An example of an instance of MyJson, as is: {} i.e. since the class has no fields, only curly brackets are serialized...