This is the presentation from my talk at the Vienna Scala Usergroup on June 8th, 2017. It is about various approaches for error and failure handling in Scala.
The Ring programming language version 1.7 book - Part 40 of 196Mahmoud Samir Fayed
This document summarizes Ring documentation for built-in classes including Tree, Math, DateTime, File, System, Debug, and DataType. It provides examples of using methods from each class, such as setting and printing tree nodes, calculating trigonometric functions with Math, getting date/time with DateTime, reading and writing files with File, and executing system commands with System. Descriptions of each class's methods are included to explain their functions.
This document discusses monads and continuations in functional programming. It provides examples of using monads like Option and List to handle failure in sequences of operations. It also discusses delimited continuations as a low-level control flow primitive that can implement exceptions, concurrency, and suspensions. The document proposes using monads to pass implicit state through programs by wrapping computations in a state transformer (ST) monad.
1. The document discusses using Scala for concurrent application development with Futures and Reactive Extensions (Rx). It provides examples of asynchronous programming using Futures, working with Observables in Rx, composing asynchronous operations, and handling errors.
2. Key concepts covered include Futures, Promises, Try monad, Observables, combining asynchronous operations, error handling, cold vs hot Observables, and concurrency control.
3. Examples demonstrate basic usage of Futures and Observables, composing operations, handling errors, working with Observable sequences, and monitoring file changes reactively.
Lightning Talk on Software Transactional Memory in Scala. The Actors Pattern has gotten a lot of attention in the Scala ecosphere, but STM of often a good first solution for solving concurrency problems. It's odd that it hasn't had as much attention in the Scala world, so this talk aims to show how easy it is to use, and compare it to typical lock-based synchronization by showing how easy it is to make errors with lock-based synchronization
The document contains 10 programs related to sorting and graph algorithms. Program 1-7 implement different sorting algorithms - insertion sort, selection sort, heap sort, quick sort, counting sort, merge sort and radix sort. Program 8 implements the greedy knapsack problem. Program 9 implements the travelling salesman problem. Program 10 implements Kruskal's algorithm to find the minimum spanning tree of a graph.
The document describes exercises on structures and strings in C programming. It defines a structure called _PLAYER to store details of players like name, date of birth, height and weight. It then shows how to define the structure, read and print records of multiple players from an array of _PLAYER structures. Functions are defined to find the tallest player, print names in descending order of height, check character cases, convert case of characters in a string, and compute operations on structures like distance between points.
Description of the Reactive Collections framework for event-driven, reactive and distributed programming, and the real-time game engine use case. See the game demos on YouTube:
http://www.youtube.com/channel/UCoyqnhi_BdpLrBVMvkNIMMw
This document discusses Go programming concepts including concurrency, reflection, interfaces, and generics. It provides examples of using channels for concurrency, reflecting over types, implementing interfaces, and defining generic functions. The examples demonstrate capabilities like mapping and reducing over collections, duplicating values, and applying transformations.
The Ring programming language version 1.7 book - Part 40 of 196Mahmoud Samir Fayed
This document summarizes Ring documentation for built-in classes including Tree, Math, DateTime, File, System, Debug, and DataType. It provides examples of using methods from each class, such as setting and printing tree nodes, calculating trigonometric functions with Math, getting date/time with DateTime, reading and writing files with File, and executing system commands with System. Descriptions of each class's methods are included to explain their functions.
This document discusses monads and continuations in functional programming. It provides examples of using monads like Option and List to handle failure in sequences of operations. It also discusses delimited continuations as a low-level control flow primitive that can implement exceptions, concurrency, and suspensions. The document proposes using monads to pass implicit state through programs by wrapping computations in a state transformer (ST) monad.
1. The document discusses using Scala for concurrent application development with Futures and Reactive Extensions (Rx). It provides examples of asynchronous programming using Futures, working with Observables in Rx, composing asynchronous operations, and handling errors.
2. Key concepts covered include Futures, Promises, Try monad, Observables, combining asynchronous operations, error handling, cold vs hot Observables, and concurrency control.
3. Examples demonstrate basic usage of Futures and Observables, composing operations, handling errors, working with Observable sequences, and monitoring file changes reactively.
Lightning Talk on Software Transactional Memory in Scala. The Actors Pattern has gotten a lot of attention in the Scala ecosphere, but STM of often a good first solution for solving concurrency problems. It's odd that it hasn't had as much attention in the Scala world, so this talk aims to show how easy it is to use, and compare it to typical lock-based synchronization by showing how easy it is to make errors with lock-based synchronization
The document contains 10 programs related to sorting and graph algorithms. Program 1-7 implement different sorting algorithms - insertion sort, selection sort, heap sort, quick sort, counting sort, merge sort and radix sort. Program 8 implements the greedy knapsack problem. Program 9 implements the travelling salesman problem. Program 10 implements Kruskal's algorithm to find the minimum spanning tree of a graph.
The document describes exercises on structures and strings in C programming. It defines a structure called _PLAYER to store details of players like name, date of birth, height and weight. It then shows how to define the structure, read and print records of multiple players from an array of _PLAYER structures. Functions are defined to find the tallest player, print names in descending order of height, check character cases, convert case of characters in a string, and compute operations on structures like distance between points.
Description of the Reactive Collections framework for event-driven, reactive and distributed programming, and the real-time game engine use case. See the game demos on YouTube:
http://www.youtube.com/channel/UCoyqnhi_BdpLrBVMvkNIMMw
This document discusses Go programming concepts including concurrency, reflection, interfaces, and generics. It provides examples of using channels for concurrency, reflecting over types, implementing interfaces, and defining generic functions. The examples demonstrate capabilities like mapping and reducing over collections, duplicating values, and applying transformations.
The Ring programming language version 1.9 book - Part 38 of 210Mahmoud Samir Fayed
The document discusses object-oriented programming concepts in Ring including classes, objects, composition, setter and getter methods, private attributes and methods, operator overloading, and inheritance. It provides examples of defining classes and creating objects that demonstrate accessing object attributes and methods using braces, passing parameters to initialization methods, and overloading operators like + to work with custom classes. The examples show how to define classes with attributes and methods to encapsulate data and behavior into reusable objects.
Scala is a multi-paradigm programming language that supports functional, object-oriented and imperative programming paradigms. The document discusses Scala's support for types, expressions, objects, functions, and provides examples of using Scala for expressions, functions, control structures, patterns, spaces and actors.
1. The document provides a lab manual for computer networks and operating systems labs containing 8 programs to implement various networking and security algorithms.
2. The programs include implementing data link layer framing methods, CRC polynomials, Dijkstra's shortest path algorithm, distance vector routing, DES encryption, breaking the DES code, and RSA encryption/decryption.
3. The document contains instructions for 8 programs to implement computer network and security algorithms as part of a lab course covering topics like data link layer, routing, encryption, and public key cryptography.
design and analysis of algorithm Lab filesNitesh Dubey
This document contains details of experiments conducted as part of a "Design and Analysis of Algorithm Lab" course. It includes 10 experiments covering algorithms like binary search, heap sort, merge sort, selection sort, insertion sort, quick sort, knapsack problem, travelling salesman problem, minimum spanning tree (using Kruskal's algorithm), and N queen problem (using backtracking). For each experiment, it provides the objective, program code implementation, and result. The document is submitted by a student to their professor for the lab session.
This document contains 8 C programming code examples demonstrating various scheduling algorithms:
1. First Come First Serve scheduling
2. Non-preemptive Shortest Job First scheduling
3. Round Robin scheduling
4. Priority scheduling
5. Banker's algorithm for deadlock avoidance
6. Producer-consumer problem synchronization
7. Dekker's algorithm for mutual exclusion
Each program example includes comments explaining the algorithm and includes functions to calculate waiting times, turnaround times, and other metrics.
The Ring programming language version 1.9 book - Part 45 of 210Mahmoud Samir Fayed
The document describes the methods available in the Ring programming language's Math, DateTime, File, System, Debug, and DataType classes. It provides documentation on each method, including its description and example output. It also includes sample code demonstrating how to use each class and its methods.
This document discusses different types of computations in functional programming such as Option, List, Future, State, and IO. It explains how to create computations of these types by wrapping values, and how to use computations by mapping and applying functions to the wrapped values. It also covers applicative functors and how they allow applying functions to multiple arguments wrapped in computations. Some examples of applicative operations on Option, List, Future, State and IO are given. Finally, it briefly discusses traversals, which allow transforming data structures of type F[A] to F[B] by applying a function A => F[B] to each element.
The Ring programming language version 1.8 book - Part 42 of 202Mahmoud Samir Fayed
The document describes the Ring documentation for version 1.8 and provides examples of using various math, date, file, system, and data type classes in the Ring standard library. Some key classes and methods described include the Math class for trigonometric, logarithmic, exponential and other math functions, the DateTime class for getting dates, times and performing date calculations, the File class for reading, writing, renaming and deleting files, and the System class for checking operating system properties and executing system commands. Examples demonstrate using the classes and methods to perform calculations, manipulate dates, read/write files, and get system information.
Rx.js allows for asynchronous programming using Observables that provide a stream of multiple values over time. The document discusses how Observables can be created from events, combined using operators like map, filter, and flatMap, and subscribed to in order to handle the stream of values. A drag and drop example is provided that creates an Observable stream of mouse drag events by combining mouse down, mouse move, and mouse up event streams. This allows treating the sequence of mouse events as a collection that can be transformed before handling the drag behavior.
The Ring programming language version 1.6 book - Part 183 of 189Mahmoud Samir Fayed
Here are the key steps to connect to a dBASE or Harbour database using ODBC in Ring:
1. Install the appropriate ODBC driver for the database you want to connect to (e.g. Microsoft dBase Driver for dBASE files, Visual FoxPro ODBC driver for Visual FoxPro databases).
2. Initialize an ODBC connection handle using odbc_init().
3. Connect to the database using odbc_connect(), passing the connection string with the driver name and data source. For example:
odbc_connect(pODBC, "Driver={Microsoft dBase Driver (*.dbf)};datasource=c:\path\to\database.dbf")
4
The Ring programming language version 1.10 book - Part 101 of 212Mahmoud Samir Fayed
This document provides documentation on using Ring, an open source programming language. It includes examples of loading Ring code files and libraries, calling functions between files, and running a Ring program. The document also answers questions about Ring concepts like using NULL values, printing objects in lists, and creating GUI applications with buttons and windows.
The Ring programming language version 1.2 book - Part 14 of 84Mahmoud Samir Fayed
This document provides documentation on mathematical and file handling functions in the Ring programming language. It describes functions for trigonometric, exponential, logarithmic, power and other common mathematical operations. It also covers functions for reading, writing, opening, closing and manipulating files, including reading/writing specific characters, lines, and binary data. Examples are provided to demonstrate the usage of many of these functions.
Scale Up with Lock-Free Algorithms @ JavaOneRoman Elizarov
This document provides a summary of a presentation on using lock-free algorithms to scale shared mutable state on the JVM. It begins with an introduction to the speaker and discusses why shared mutable state is needed for big data and real-time processing. It then uses a toy problem of implementing a concurrent stack to demonstrate the challenges of synchronization and contention. The presentation introduces the use of atomic references and compare-and-set operations to implement lock-free push and pop operations on the concurrent stack in a non-blocking manner, improving scalability.
The Ring programming language version 1.8 book - Part 35 of 202Mahmoud Samir Fayed
This document discusses object-oriented programming in Ring and provides examples of defining classes and creating objects. It covers defining classes with attributes and methods, creating objects using the New keyword, accessing object attributes and methods using dot notation or braces, passing parameters to initialization methods, and defining private attributes and methods. Inheritance, dynamic attributes, packages, printing objects, and sorting lists of objects are also briefly mentioned.
The Ring programming language version 1.3 book - Part 32 of 88Mahmoud Samir Fayed
This document provides documentation on generating web pages in Ring. It demonstrates how to:
- Create a header and list of number objects to display in a template
- Use functions like boxstart(), text(), html(), and newline() to output HTML elements and code
- Define classes like Header and Number to represent data to display
- Generate a web page that displays hashed values of a form input using functions like MD5(), SHA1(), etc.
- Include random images from a folder on the server using the random() and dir() functions
- Create unordered and ordered lists to display items using ulstart(), listart(), etc.
- Generate an HTML table to display a number and its square using
The Ring programming language version 1.10 book - Part 33 of 212Mahmoud Samir Fayed
This document provides documentation on file handling functions in the Ring programming language. It describes functions for reading and writing files, such as Read(), Write(), Dir(), Rename(), Remove(), fopen(), fclose(), as well as functions for file positioning and input/output such as fseek(), ftell(), rewind(). Examples are provided to demonstrate usage of these functions for reading file contents, writing strings to files, getting directory listings, and copying files. Mathematical functions are also briefly covered, along with functions for random number generation and working with unsigned numbers.
The document discusses implementation of linked lists in C programming language. It includes functions to create, insert, delete and display nodes in a linked list. The functions demonstrated are to insert nodes at the beginning, end or after a particular node. It also includes functions to delete nodes from the beginning, end or anywhere in the list. The main function uses a switch case to call these functions and operate on a linked list based on user input.
Improving Correctness With Type - Goto Con BerlinIain Hull
A talk I gave at Goto Con Berlin in December 2015
http://workday.github.io/scala/2015/12/03
This talk is aimed at Scala developers with a background in object oriented programming who want to learn new ways to use types to improve the correctness of their code. It introduces the topic in a practical fashion, concentrating on the “easy wins” developers can apply to their code today.
Learning Rx does not have to be boring like working your way through theoretical sermons about esoteric concepts like category theory and duality. Life is too short for that kind of abstract nonsense.
So what is a better way to spend a hot summer day with an ice-cold drink, or a cold winter night with a piping hot drink, than to learn Rx by writing an awesome platform game? In this talk, Erik will walk you through many of the features of Rx through programming a friendly bug to run across a lushy grassy meadow and jump for the stars.
The Ring programming language version 1.9 book - Part 38 of 210Mahmoud Samir Fayed
The document discusses object-oriented programming concepts in Ring including classes, objects, composition, setter and getter methods, private attributes and methods, operator overloading, and inheritance. It provides examples of defining classes and creating objects that demonstrate accessing object attributes and methods using braces, passing parameters to initialization methods, and overloading operators like + to work with custom classes. The examples show how to define classes with attributes and methods to encapsulate data and behavior into reusable objects.
Scala is a multi-paradigm programming language that supports functional, object-oriented and imperative programming paradigms. The document discusses Scala's support for types, expressions, objects, functions, and provides examples of using Scala for expressions, functions, control structures, patterns, spaces and actors.
1. The document provides a lab manual for computer networks and operating systems labs containing 8 programs to implement various networking and security algorithms.
2. The programs include implementing data link layer framing methods, CRC polynomials, Dijkstra's shortest path algorithm, distance vector routing, DES encryption, breaking the DES code, and RSA encryption/decryption.
3. The document contains instructions for 8 programs to implement computer network and security algorithms as part of a lab course covering topics like data link layer, routing, encryption, and public key cryptography.
design and analysis of algorithm Lab filesNitesh Dubey
This document contains details of experiments conducted as part of a "Design and Analysis of Algorithm Lab" course. It includes 10 experiments covering algorithms like binary search, heap sort, merge sort, selection sort, insertion sort, quick sort, knapsack problem, travelling salesman problem, minimum spanning tree (using Kruskal's algorithm), and N queen problem (using backtracking). For each experiment, it provides the objective, program code implementation, and result. The document is submitted by a student to their professor for the lab session.
This document contains 8 C programming code examples demonstrating various scheduling algorithms:
1. First Come First Serve scheduling
2. Non-preemptive Shortest Job First scheduling
3. Round Robin scheduling
4. Priority scheduling
5. Banker's algorithm for deadlock avoidance
6. Producer-consumer problem synchronization
7. Dekker's algorithm for mutual exclusion
Each program example includes comments explaining the algorithm and includes functions to calculate waiting times, turnaround times, and other metrics.
The Ring programming language version 1.9 book - Part 45 of 210Mahmoud Samir Fayed
The document describes the methods available in the Ring programming language's Math, DateTime, File, System, Debug, and DataType classes. It provides documentation on each method, including its description and example output. It also includes sample code demonstrating how to use each class and its methods.
This document discusses different types of computations in functional programming such as Option, List, Future, State, and IO. It explains how to create computations of these types by wrapping values, and how to use computations by mapping and applying functions to the wrapped values. It also covers applicative functors and how they allow applying functions to multiple arguments wrapped in computations. Some examples of applicative operations on Option, List, Future, State and IO are given. Finally, it briefly discusses traversals, which allow transforming data structures of type F[A] to F[B] by applying a function A => F[B] to each element.
The Ring programming language version 1.8 book - Part 42 of 202Mahmoud Samir Fayed
The document describes the Ring documentation for version 1.8 and provides examples of using various math, date, file, system, and data type classes in the Ring standard library. Some key classes and methods described include the Math class for trigonometric, logarithmic, exponential and other math functions, the DateTime class for getting dates, times and performing date calculations, the File class for reading, writing, renaming and deleting files, and the System class for checking operating system properties and executing system commands. Examples demonstrate using the classes and methods to perform calculations, manipulate dates, read/write files, and get system information.
Rx.js allows for asynchronous programming using Observables that provide a stream of multiple values over time. The document discusses how Observables can be created from events, combined using operators like map, filter, and flatMap, and subscribed to in order to handle the stream of values. A drag and drop example is provided that creates an Observable stream of mouse drag events by combining mouse down, mouse move, and mouse up event streams. This allows treating the sequence of mouse events as a collection that can be transformed before handling the drag behavior.
The Ring programming language version 1.6 book - Part 183 of 189Mahmoud Samir Fayed
Here are the key steps to connect to a dBASE or Harbour database using ODBC in Ring:
1. Install the appropriate ODBC driver for the database you want to connect to (e.g. Microsoft dBase Driver for dBASE files, Visual FoxPro ODBC driver for Visual FoxPro databases).
2. Initialize an ODBC connection handle using odbc_init().
3. Connect to the database using odbc_connect(), passing the connection string with the driver name and data source. For example:
odbc_connect(pODBC, "Driver={Microsoft dBase Driver (*.dbf)};datasource=c:\path\to\database.dbf")
4
The Ring programming language version 1.10 book - Part 101 of 212Mahmoud Samir Fayed
This document provides documentation on using Ring, an open source programming language. It includes examples of loading Ring code files and libraries, calling functions between files, and running a Ring program. The document also answers questions about Ring concepts like using NULL values, printing objects in lists, and creating GUI applications with buttons and windows.
The Ring programming language version 1.2 book - Part 14 of 84Mahmoud Samir Fayed
This document provides documentation on mathematical and file handling functions in the Ring programming language. It describes functions for trigonometric, exponential, logarithmic, power and other common mathematical operations. It also covers functions for reading, writing, opening, closing and manipulating files, including reading/writing specific characters, lines, and binary data. Examples are provided to demonstrate the usage of many of these functions.
Scale Up with Lock-Free Algorithms @ JavaOneRoman Elizarov
This document provides a summary of a presentation on using lock-free algorithms to scale shared mutable state on the JVM. It begins with an introduction to the speaker and discusses why shared mutable state is needed for big data and real-time processing. It then uses a toy problem of implementing a concurrent stack to demonstrate the challenges of synchronization and contention. The presentation introduces the use of atomic references and compare-and-set operations to implement lock-free push and pop operations on the concurrent stack in a non-blocking manner, improving scalability.
The Ring programming language version 1.8 book - Part 35 of 202Mahmoud Samir Fayed
This document discusses object-oriented programming in Ring and provides examples of defining classes and creating objects. It covers defining classes with attributes and methods, creating objects using the New keyword, accessing object attributes and methods using dot notation or braces, passing parameters to initialization methods, and defining private attributes and methods. Inheritance, dynamic attributes, packages, printing objects, and sorting lists of objects are also briefly mentioned.
The Ring programming language version 1.3 book - Part 32 of 88Mahmoud Samir Fayed
This document provides documentation on generating web pages in Ring. It demonstrates how to:
- Create a header and list of number objects to display in a template
- Use functions like boxstart(), text(), html(), and newline() to output HTML elements and code
- Define classes like Header and Number to represent data to display
- Generate a web page that displays hashed values of a form input using functions like MD5(), SHA1(), etc.
- Include random images from a folder on the server using the random() and dir() functions
- Create unordered and ordered lists to display items using ulstart(), listart(), etc.
- Generate an HTML table to display a number and its square using
The Ring programming language version 1.10 book - Part 33 of 212Mahmoud Samir Fayed
This document provides documentation on file handling functions in the Ring programming language. It describes functions for reading and writing files, such as Read(), Write(), Dir(), Rename(), Remove(), fopen(), fclose(), as well as functions for file positioning and input/output such as fseek(), ftell(), rewind(). Examples are provided to demonstrate usage of these functions for reading file contents, writing strings to files, getting directory listings, and copying files. Mathematical functions are also briefly covered, along with functions for random number generation and working with unsigned numbers.
The document discusses implementation of linked lists in C programming language. It includes functions to create, insert, delete and display nodes in a linked list. The functions demonstrated are to insert nodes at the beginning, end or after a particular node. It also includes functions to delete nodes from the beginning, end or anywhere in the list. The main function uses a switch case to call these functions and operate on a linked list based on user input.
Improving Correctness With Type - Goto Con BerlinIain Hull
A talk I gave at Goto Con Berlin in December 2015
http://workday.github.io/scala/2015/12/03
This talk is aimed at Scala developers with a background in object oriented programming who want to learn new ways to use types to improve the correctness of their code. It introduces the topic in a practical fashion, concentrating on the “easy wins” developers can apply to their code today.
Learning Rx does not have to be boring like working your way through theoretical sermons about esoteric concepts like category theory and duality. Life is too short for that kind of abstract nonsense.
So what is a better way to spend a hot summer day with an ice-cold drink, or a cold winter night with a piping hot drink, than to learn Rx by writing an awesome platform game? In this talk, Erik will walk you through many of the features of Rx through programming a friendly bug to run across a lushy grassy meadow and jump for the stars.
Watch video (in Hebrew): http://parleys.com/play/53f7a9cce4b06208c7b7ca1e
Type classes are a fundamental feature of Scala, which allows you to layer new functionality on top of existing types externally, i.e. without modifying or recompiling existing code. When combined with implicits, this is a truly remarkable tool that enables many of the advanced features offered by the Scala library ecosystem. In this talk we'll go back to basics: how type classes are defined and encoded, and cover several prominent use cases.
A talk given at the Underscore meetup on 19 August, 2014.
The document discusses improving program correctness through the use of types in Scala. It covers techniques like defensive programming, failing fast, design by contract, and using wrapper types to control values and operations. Specific examples include creating algebraic data types to model application data, using tagged types to enforce constraints, and defining wrapper types for currencies and amounts to prevent bugs. The overall message is that types can help catch errors earlier and design programs in a way that is less error-prone.
Why we are submitting this talk? Because Go is cool and we would like to hear more about this language ;-). In this talk we would like to tell you about our experience with development of microservices with Go. Go enables devs to create readable, fast and concise code, this - beyond any doubt is important. Apart from this we would like to leverage our test driven habbits to create bulletproof software. We will also explore other aspects important for adoption of a new language.
This document discusses functional domain-driven design and the use of monads. It begins by stating that functional domain-driven design is still a work in progress. It then provides definitions of monads and functions as they relate to category theory. The document discusses how monads can be used with a functional approach to domain-driven design. It also includes brief biographical information about the software developer who posted this content.
Taming Distribution: Formal Protocols for Akka TypedRoland Kuhn
Cloud computing, reactive systems, microservices: distributed programming has become the norm. But while the shift to loosely coupled message-based systems has manifest benefits in terms of resilience and elasticity, our tools for ensuring correct behavior has not grown at the same pace. Statically typed languages like Java and Scala allow us to exclude large classes of programming errors before the first test is run. Unfortunately, these guarantees are limited to the local behavior within a single process, the compiler cannot tell us that we are sending the wrong JSON structure to a given web service. Therefore distribution comes at the cost of having to write large test suites, with timing-dependent non-determinism.
In this presentation we take a first peek at ways out of this dilemma. The principles are demonstrated on the simplest distributed system: Actors. We show how parameterized ActorRefs à la Akka Typed together with effect tracking similar to HLists can help us define what an Actor can and cannot do during its lifetime—and have the compiler yell at us when we do it wrong.
aming distribution: formal protocols for Akka TypedJ On The Beach
Cloud computing, reactive systems, microservices: distributed programming has become the norm. But while the shift to loosely coupled message-based systems has manifest benefits in terms of resilience and elasticity, our tools for ensuring correct behavior has not grown at the same pace. Statically typed languages like Java and Scala allow us to exclude large classes of programming errors before the first test is run. Unfortunately, these guarantees are limited to the local behavior within a single process, the compiler cannot tell us that we are sending the wrong JSON structure to a given web service. Therefore distribution comes at the cost of having to write large test suites, with timing-dependent non-determinism.
In this presentation we take a first peek at ways out of this dilemma. The principles are demonstrated on the simplest distributed system: Actors. We show how parameterized ActorRefs à la Akka Typed together with effect tracking similar to HLists can help us define what an Actor can and cannot do during its lifetime—and have the compiler yell at us when we do it wrong.
Programs written in functional programming languages, like Scala and Clojure, are less complex than their Java counterpart. They are easier to reason about once you have passed the initial learning curve for the language. Even though functional programming has become syntactically sane with the introduction of lambda, the functional languages still present competitive features such as tail call optimization, lazy evaluation and persistent data structures. These features can be implemented as Java libraries. You will see how they can radically reduce complexity of Java code, today.
JAVA.Q4 Create a Time class. This class will represent a point in.pdfkarymadelaneyrenne19
JAVA.
Q4: Create a Time class. This class will represent a point in time, such as a departure time. It
should contain 2 constructors, 2 instance variables (hour and minute), and 10 methods (see
below). All methods but toString should be in terms of the 24 hour format. [30 points]
default constructor: Creates a Time object for 12:00AM.
overloaded constructor: Creates a Time object at a specific hour and minute.
getHour(): Returns an integer representing the hour of the Time object.
getMinute(): Returns an integer representing the minute of the Time object.
addHours(...): Updates the object by moving it forward a number of hours.
addMinute(...): Updates the object by moving it forward a number of minutes. (Hint: Be careful
that you don\'t allow minutes to be more than 59.)
addTime(...): Updates the object by moving it forward by the hour and minute from another
Time object.
getCopy(...): Returns a new Time object that has the same hour and minute of the existing Time
object.
isEarlierThan(...): Returns true if this Time object is earlier than another Time object.
isSameTime(...): Returns true if this Time object is the same as another Time object.
isLaterThan(...): Returns true if this Time object is later than another Time object.
toString(): Returns a string representing the Time object. Uses 12 hour AM/PM format and pads
minutes to be two digits. See the sample output for an example.
Q5: Create a Flight class that uses the Plane and Time class. This class will represent a flight
between two airports, using a specific Plane, and departing at a specific Time. It should contain a
constructor, 7 instance variables (plane, flight number, cost, departure, duration, source,
destination), and 9 methods (see below). [25 points]
overloaded constructor: Creates a Flight object that is setup up with a Plane, a flight number, a
cost, a departure Time, a duration time, a source Airport, and a destination Airport.
getPlane(): Returns the Plane that operates this flight.
getNumber(): Returns the flight number.
getCost(): Returns the flight cost.
getDestination(): Returns the destination Airport.
getDeparture(): Returns the departure Time.
getArrival(): Returns a Time object with the arrival time (computed from the departure time and
duration).
getSource(): Returns a Airport object for the departure location.
toOverviewString(): Returns a String representing an overview of the flight. Use NumberFormat
to display the price. See the sample output for an example.
toDetailedString(): Returns a String representing the flight\'s detail information. See the sample
output for an example.
Included below is an overall UML diagram that describes the three classes you will be
constructing. It provides a useful summary of all of the methods you are expected to implement,
and their corresponding types and visibility. Notice that one private method is listed here
(formatDigits in Time) that isn\'t mentioned above. This is a method that was in our solution, you
may not need.
Kamil Chmielewski, Jacek Juraszek - "Hadoop. W poszukiwaniu złotego młotka."sjabs
The document discusses Hadoop and its applications. It provides examples of companies like Facebook and their use of Hadoop. It also discusses Hadoop components like HDFS, MapReduce, Pig and HBase. It provides examples of using Hadoop with databases like MongoDB and search engines like Solr. It notes that not every problem requires large-scale solutions and discusses potential use cases for Hadoop including log analysis, indexing documents and building recommendation systems.
Functional programming in Scala. Looking at various examples of defining a program first and executing it at some later stage, separating pure functions from side effects.
Improving Correctness with Types Kats ConfIain Hull
A talk I gave at Functional Kats in September 2015
http://workday.github.io/scala/2015/03/17/scala-days-improving-correctness-with-types/
This talk is aimed at Scala developers with a background in object oriented programming who want to learn new ways to use types to improve the correctness of their code. It introduces the topic in a practical fashion, concentrating on the “easy wins” developers can apply to their code today.
http://functionalkats.com/#nav-speakers
This document provides an introduction to monads through a presentation given by Mikhail Girkin. Some key points:
1. Monads are commonly used in functional programming to represent computations or chaining of operations. They consist of a type, a unit operation, and a bind (flatMap) operation.
2. Many languages like C# and Java already use monads through things like flatMap, they just don't refer to them as monads. Collections like Seq are monads.
3. Option and Try are examples of monads used to handle potential failures gracefully. For-comprehensions provide a cleaner way to write code involving monads compared to nested flatMaps.
4. Other
This document discusses Scala features for parallelism, concurrency, and reactive programming. Some key points include:
- Scala supports parallel collections that can perform operations like map, reduce, and filter in parallel.
- Futures represent asynchronous computations whose results are not yet known. They allow non-blocking operations.
- Actors are units of concurrency that communicate asynchronously by message passing. They encapsulate state and behavior.
- Akka is a toolkit for building highly concurrent, distributed, and fault-tolerant event-driven applications using actors. It implements the actor model in Scala.
The document introduces Scala and provides an overview of Scala basics including variables, functions, objects, classes, traits, pattern matching, for-comprehensions and more. It also discusses Scala's capabilities for generic programming, lazy evaluation, and integration with Java. Examples are provided throughout to demonstrate Scala concepts.
The document discusses several common Java anti-patterns, including:
1) Approving a task by rejecting it in a method called "approve".
2) Avoiding the use of helper libraries to simplify tasks like file name parsing.
3) Using reflection when direct method calls would suffice.
Actors provide a model for building concurrent and distributed applications using message passing between isolated computing entities called actors. Akka is an implementation of the actor model that allows building scalable and fault-tolerant applications on the JVM. Akka provides features like remote deployment of actors, asynchronous message passing, supervision strategies, and dispatchers for configuring how messages are processed.
cats.effect.IO - Scala Vienna Meetup February 2019Daniel Pfeiffer
IO[A] is a datatype in Cats Effect that represents side effects, allowing synchronous or asynchronous execution. It differs from Future[A] in that it maintains referential transparency and is lazily evaluated. IO[A] can represent both synchronous and asynchronous computations, where synchronous execution waits for completion before continuing and asynchronous execution allows continuing without waiting. Cats Effect provides features for concurrency, cancellation, parallelism and resource management using IO[A].
The document discusses the strategy of starting with a monolithic application architecture and then gradually transitioning to microservices. It describes one company's experience starting with a Java/Spring monolith and eventually introducing microservices by first creating an internal read model as a separate service. The process involved distributing event handling across services, using an API gateway, feature toggles, and a "replicate and replace" strategy of introducing new services. Key lessons included investing in continuous deployment pipelines and automation, and that migrating code to services takes more time and effort than initially expected.
This are the slides for my lightning talk at the Vienna Scala Usergroup on September 14th 2017 about running Playframework Applications inside Docker containers.
This is the presentation from my user group talk at the Java Vienna User Group on May 8th, 2017. The presentation is about building an event sourced system using AWS services and the Akka toolkit.
"'Capture all changes to an application state as a sequence of events' is what Martin Fowler said about Event Sourcing in 2005 and what is the starting point into that topic for this talk.
I will demonstrate how you can store events using Akka Persistence and then distribute them via AWS to be consumed by your other services.
An event based architecture has lots of technical and organisational benefits for your development team. It can be a huge gain for your development process, but can also be difficult to implement as there are lots of challenges.
I will discuss the good as well as the bad things and provide solutions to overcome common pitfalls and aforementioned challenges."
Driving Business Innovation: Latest Generative AI Advancements & Success StorySafe Software
Are you ready to revolutionize how you handle data? Join us for a webinar where we’ll bring you up to speed with the latest advancements in Generative AI technology and discover how leveraging FME with tools from giants like Google Gemini, Amazon, and Microsoft OpenAI can supercharge your workflow efficiency.
During the hour, we’ll take you through:
Guest Speaker Segment with Hannah Barrington: Dive into the world of dynamic real estate marketing with Hannah, the Marketing Manager at Workspace Group. Hear firsthand how their team generates engaging descriptions for thousands of office units by integrating diverse data sources—from PDF floorplans to web pages—using FME transformers, like OpenAIVisionConnector and AnthropicVisionConnector. This use case will show you how GenAI can streamline content creation for marketing across the board.
Ollama Use Case: Learn how Scenario Specialist Dmitri Bagh has utilized Ollama within FME to input data, create custom models, and enhance security protocols. This segment will include demos to illustrate the full capabilities of FME in AI-driven processes.
Custom AI Models: Discover how to leverage FME to build personalized AI models using your data. Whether it’s populating a model with local data for added security or integrating public AI tools, find out how FME facilitates a versatile and secure approach to AI.
We’ll wrap up with a live Q&A session where you can engage with our experts on your specific use cases, and learn more about optimizing your data workflows with AI.
This webinar is ideal for professionals seeking to harness the power of AI within their data management systems while ensuring high levels of customization and security. Whether you're a novice or an expert, gain actionable insights and strategies to elevate your data processes. Join us to see how FME and AI can revolutionize how you work with data!
Threats to mobile devices are more prevalent and increasing in scope and complexity. Users of mobile devices desire to take full advantage of the features
available on those devices, but many of the features provide convenience and capability but sacrifice security. This best practices guide outlines steps the users can take to better protect personal devices and information.
How to Get CNIC Information System with Paksim Ga.pptxdanishmna97
Pakdata Cf is a groundbreaking system designed to streamline and facilitate access to CNIC information. This innovative platform leverages advanced technology to provide users with efficient and secure access to their CNIC details.
Ivanti’s Patch Tuesday breakdown goes beyond patching your applications and brings you the intelligence and guidance needed to prioritize where to focus your attention first. Catch early analysis on our Ivanti blog, then join industry expert Chris Goettl for the Patch Tuesday Webinar Event. There we’ll do a deep dive into each of the bulletins and give guidance on the risks associated with the newly-identified vulnerabilities.
Taking AI to the Next Level in Manufacturing.pdfssuserfac0301
Read Taking AI to the Next Level in Manufacturing to gain insights on AI adoption in the manufacturing industry, such as:
1. How quickly AI is being implemented in manufacturing.
2. Which barriers stand in the way of AI adoption.
3. How data quality and governance form the backbone of AI.
4. Organizational processes and structures that may inhibit effective AI adoption.
6. Ideas and approaches to help build your organization's AI strategy.
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/building-and-scaling-ai-applications-with-the-nx-ai-manager-a-presentation-from-network-optix/
Robin van Emden, Senior Director of Data Science at Network Optix, presents the “Building and Scaling AI Applications with the Nx AI Manager,” tutorial at the May 2024 Embedded Vision Summit.
In this presentation, van Emden covers the basics of scaling edge AI solutions using the Nx tool kit. He emphasizes the process of developing AI models and deploying them globally. He also showcases the conversion of AI models and the creation of effective edge AI pipelines, with a focus on pre-processing, model conversion, selecting the appropriate inference engine for the target hardware and post-processing.
van Emden shows how Nx can simplify the developer’s life and facilitate a rapid transition from concept to production-ready applications.He provides valuable insights into developing scalable and efficient edge AI solutions, with a strong focus on practical implementation.
AI 101: An Introduction to the Basics and Impact of Artificial IntelligenceIndexBug
Imagine a world where machines not only perform tasks but also learn, adapt, and make decisions. This is the promise of Artificial Intelligence (AI), a technology that's not just enhancing our lives but revolutionizing entire industries.
Unlock the Future of Search with MongoDB Atlas_ Vector Search Unleashed.pdfMalak Abu Hammad
Discover how MongoDB Atlas and vector search technology can revolutionize your application's search capabilities. This comprehensive presentation covers:
* What is Vector Search?
* Importance and benefits of vector search
* Practical use cases across various industries
* Step-by-step implementation guide
* Live demos with code snippets
* Enhancing LLM capabilities with vector search
* Best practices and optimization strategies
Perfect for developers, AI enthusiasts, and tech leaders. Learn how to leverage MongoDB Atlas to deliver highly relevant, context-aware search results, transforming your data retrieval process. Stay ahead in tech innovation and maximize the potential of your applications.
#MongoDB #VectorSearch #AI #SemanticSearch #TechInnovation #DataScience #LLM #MachineLearning #SearchTechnology
Generating privacy-protected synthetic data using Secludy and MilvusZilliz
During this demo, the founders of Secludy will demonstrate how their system utilizes Milvus to store and manipulate embeddings for generating privacy-protected synthetic data. Their approach not only maintains the confidentiality of the original data but also enhances the utility and scalability of LLMs under privacy constraints. Attendees, including machine learning engineers, data scientists, and data managers, will witness first-hand how Secludy's integration with Milvus empowers organizations to harness the power of LLMs securely and efficiently.
OpenID AuthZEN Interop Read Out - AuthorizationDavid Brossard
During Identiverse 2024 and EIC 2024, members of the OpenID AuthZEN WG got together and demoed their authorization endpoints conforming to the AuthZEN API
Climate Impact of Software Testing at Nordic Testing DaysKari Kakkonen
My slides at Nordic Testing Days 6.6.2024
Climate impact / sustainability of software testing discussed on the talk. ICT and testing must carry their part of global responsibility to help with the climat warming. We can minimize the carbon footprint but we can also have a carbon handprint, a positive impact on the climate. Quality characteristics can be added with sustainability, and then measured continuously. Test environments can be used less, and in smaller scale and on demand. Test techniques can be used in optimizing or minimizing number of tests. Test automation can be used to speed up testing.
Have you ever been confused by the myriad of choices offered by AWS for hosting a website or an API?
Lambda, Elastic Beanstalk, Lightsail, Amplify, S3 (and more!) can each host websites + APIs. But which one should we choose?
Which one is cheapest? Which one is fastest? Which one will scale to meet our needs?
Join me in this session as we dive into each AWS hosting service to determine which one is best for your scenario and explain why!
“An Outlook of the Ongoing and Future Relationship between Blockchain Technologies and Process-aware Information Systems.” Invited talk at the joint workshop on Blockchain for Information Systems (BC4IS) and Blockchain for Trusted Data Sharing (B4TDS), co-located with with the 36th International Conference on Advanced Information Systems Engineering (CAiSE), 3 June 2024, Limassol, Cyprus.
7. THE PROBLEM DOMAIN
sealed trait TimeEntryStatus
case object Open extends TimeEntryStatus
case object Accepted extends TimeEntryStatus
case object Declined extends TimeEntryStatus
case class TimeEntry(
id: UUID,
begin: LocalDateTime,
end: LocalDateTime,
status: TimeEntryStatus
)
8. THE PROBLEM DOMAIN
val timeEntry = TimeEntry(
id = UUID.randomUUID,
begin = LocalDateTime.now.minusHours(1),
end = LocalDateTime.now,
status = Open
)
11. A JAVAISH
SOLUTION
Many of us are used to
develop like this
Failures handling with
exceptions
Better solutions
already exist
12. A JAVAISH SOLUTION
abstract class TimeEntryException(message: String) extends Exception
case class TimeEntryAlreadyExistsException(id: UUID)
extends TimeEntryException(s"Time Entry with id $id already exists.")
case class TimeEntryDoesNotExistException(id: UUID)
extends TimeEntryException(s"Time Entry with id $id does not exist.")
13. A JAVAISH SOLUTION
class TimeEntryService {
def create(t: TimeEntry): Unit = {
if (timeEntries.contains(t.id)) {
throw TimeEntryAlreadyExistsException(t.id)
} else {
timeEntries = timeEntries + (t.id -> t)
}
}
}
19. MY PRECIOUS
sealed trait TimeEntryFailure
case class ValidationFailed(failures: List[String])
extends TimeEntryFailure
case class TimeEntryDoesNotExist(id: UUID)
extends TimeEntryFailure
case class TimeEntryAlreadyExists(id: UUID)
extends TimeEntryFailure
21. ... AND MATCH IT
//type TimeEntryResult[A] = Either[TimeEntryFailure,A]
val result: TimeEntryResult[Unit] = for {
_ <- service.create(entry)
_ <- service.create(entry)
_ <- service.accept(entry.id)
} yield ()
result.fold(
{
case TimeEntryDoesNotExist(id) => println("Sorry, the time entry does not exis
case TimeEntryAlreadyExists(id) => println("Sorry, the time entry already exis
}, { _ =>
println("Yeaaah, success!")
}
)
23. LET'S MAKE THIS A HARD CONSTRAINT
scalacOptions += "-Xfatal-warnings",
[error] /Users/daniel/presentations/2017-06-08_error-handling-in-scala/
code/src/main/scala/com/github/dpfeiffer/errorhandling/either/
ExampleWithEither.scala:60: match may not be exhaustive.
[error] It would fail on the following input: ValidationFailed(_)
[error] {
[error] ^
[error] one error found
26. ... THAT LOOKS LIKE THE TRY
val result = for {
_ <- service.create(timeEntry)
_ <- service.accept(timeEntry.id)
_ <- service.create(timeEntry)
} yield ()
result.onComplete {
case Success(_) => println("Succeeded.")
case Failure(ex) => println(s"Exception occurred. ${ex.getMessage}")
}
33. WRAPPING EVERYTHING IN A NEW
MONAD
type FutureEither = EitherT[Future, String, String]
val a: FutureEither = EitherT(Future(Right("right")))
val b: FutureEither = EitherT(Future(Left("left"))
val c: FutureEither = EitherT.right(Future("right"))
val d: FutureEither = EitherT.left(Future("left"))
val e: FutureEither = EitherT.fromEither(Right("right"))
34. THE USAGE LOOKS GOOD IF...
we only use TimeEntryResult[_]
//type TimeEntryResult[A] = EitherT[Future,TimeEntryFailure,A]
val result: TimeEntryResult[Unit] = for {
_ <- service.create(entry)
_ <- service.create(entry)
_ <- service.accept(entry.id)
} yield ()
result
.fold(handleFailure, _ => println("Success!!!"))
.onComplete {
case Failure(t) => println("Oh noooo!")
case Success(_) =>
}