It is a more powerful version of the switch statement in java and it can likewise be used in place of a series of ifelse statements. There are a few interactive resources for trying out scala, to get a look and feel of the language. A successful match can also deconstruct a value into its constituent parts. Pechkinpechkinsynchronizedutil at master gmannypechkin. Ive been working with scala quite a bit lately, and in an effort to get it all to stick in my brain, ive created a scala cheat sheet in pdf format, which you can download below this pdf is very different from my earlier scala cheat sheet in html format, as i tried to create something that works much better in a print format. When you see forall, you can read it as, for all possible elements of the type shown, run the block of code that follows. Rendering html into pdf using wkhtmltopdf industrial. There are a few different ways that this problem can be solved.
Scala is a statically typed language support for generics. I would suggest that you create a webpage that displays what you want printed and place it at a known location in your web app. The following set of sections provides a quick tutorial on the scala language. In the past weve set this up for clients wanting a save to pdf version of a page. Guide for data science professionals 2017 by pascal bugnion, arun manivannan, patrick r. Is that normal that on some html page, few images always the same are not converted. Scala has been created by martin odersky and he released the first version in 2003. There currently isnt much in the way of good scala lift framework documentation, particularly for creating web forms, but i thought id share whatever good links i can find currently there are only two good links about creating lift forms, and both of those are on the official website. Learning concurrent programming in scala second edition 2017 by aleksandar prokopec.
This pdf is very different from my earlier scala cheat sheet in html format, as i tried to create something that works much better in a print format. Fetching latest commit cannot retrieve the latest commit at this time. Pechkinpechkinreference at master gmannypechkin github. If it stumbles across a list that makes the property false, scalacheck will test the property with smaller and smaller variants of that list, as long as the property still fails. Sep 16, 20 with pechkin you can create a pdf file by passing to the library a string containing html markup. The contents is based on the moocs functional programming principles in scala and functional program design in scala.
I first tried to get it all in one page, but short of using a one. Introduction to scala and spark sei digital library. For example, we could extend our readme example by filtering the lines in the file that contain a word, such as python, as shown in example 24 for python and example 25 for scala. In contrast to scala collections breeze data structures do support negative indexes, for example to obtain the last value in a vector. Scala does not require semicolons at the end of state. The programming language scala has many characteristics that make it popular for data science use cases among other languages like r and python. Its a great way to get a brief introduction to scala while testing your knowledge along the way. This tells you that forall is a case class or function that takes a block of code as an input value what you have no way of knowing at this time is that forall is an important ingredient in the scalacheck recipe. Scala high performance programming 2016 by vincent theron, michael diamant. After releasing this library i quickly realized that supporting it for others would be more about understanding the quirks of wkhtmltopdf itself than adding features and fixes on top of it. Htmltopdfdocument extracted from open source projects. The canonical example of this is function composition.
Mar 06, 2016 another one would be element wise manipulation, of which weve already seen an example with the splat operator. As mentioned previously, pechkin generates a pdf and return the data as a byte array, that means that you will need to write that data somehow by yourself. Simple html to pdf example using tuespechkin github. Just replace with the html page you want you can use local files as well. Building a recommendation engine with scala 2016 by saleem ansari. Scala smoothly integrates the features of objectoriented and functional languages. Data visualization is an integral part of data science. Create new file find file history pechkin pechkinsynchronized util latest commit. Predef import anywhere inside the client scala file, not just at the top of the file, for scoped relevance, see example in package section. Int implements orderedmyclass all the variables and functions have types that are defined at compile time the compiler will find many unintended programming errors. Or try something like the untested code below your true code will be more complicated, this is just a demopoc.
Instances of option are either an instance of scala. The functional implementation makes it look like scala is a language thats specialized for functional operations on arrays. First, in regards to language purity, allowing for them would have meant adding a special rule to the language, and the language designers wanted to. Immutable data structures and functional constructs are some of the features that make it so attractive to data scientists. If you can i would suggest using the exe i think its simpler. The combination of play 2, scala, squeryl, json, coffeescript, jquery, and scalatest provides a very efficient way to build and test modern web applications. The top differences between java, scala, groovy, clojure. I first tried to get it all in one page, but short of using a onepoint font, that wasnt going to happen. Dec 10, 2008 there is a formal specification of the scala language, but the language specification tries for precision at the expense of readability.
Scala and java fully compatible with java java code can be used from scala, and vice versa compiles to. Scala span example the span method lets you split a stream into two parts, by providing a function that detects the dividing line where you want the split to occur. A little more complete, because you can set the margins of page create global configuration object globalconfig gc new globalconfig. Hi, if i convert pdf from local html file, images are omited. Sep 18, 2012 hey gman and thank you for this great wrapper. Mar 05, 2016 recently, i had to work on a task where we needed to create a pdf version of a silverlight page. User guide html pdf example analysis reports from the getting started chapter. Heres the download link for my scala cheat sheet file. With the original pechkin library the dlls used for rendering the pdf. Getting specific values from a vector can be achieved by using an index. With filestream you can read from, write to, open, and close files on a file. The contents is based on the moocs functional programming principles in scala and functional program design in scala the target audience is people who already have some experience of programming and who are familiar with the jvm elements of programming. This is of particular importance to scala, as its grammar has a high degree of overlap.
With pechkin you can create a pdf file by passing to the library a string containing html markup. You can follow along to build a simple databasedriven web application, test the application, and deploy it on the cloud. Although this book doesnt cover every detail of scala, it is quite comprehensive and should serve as an approachable language reference as you become more adept at programming in scala. Familiar higherorder functions are implemented as methods of. For example, if you run the site using the visual studio builtin web server and. Scala source code is intended to be compiled to java bytecode, so that the resulting executable code runs on a java virtual machine. Then use the url version of the tuespechkin routines the ones i use to supply a path to your print page. You can rate examples to help us improve the quality of examples. We will write the pdf into a file using the filestream class included in the assembly system. Use nuget to get pechkin into your project then use the following code. Trusted for over 23 years, our modern delphi is the preferred choice of object pascal developers for creating cool apps across devices.
There is a formal specification of the scala language, but the language specification tries for precision at the expense of readability. For example, if a property takes a list of integers as its parameter, then scalacheck will first generate many different integer lists and feed them to the property. Scala can be used to concisely express pipelines of operations map, flatmap, filter, groupby, operate on entire collections with one element in the functions scope at a time. Nov 03, 2019 trusted for over 23 years, our modern delphi is the preferred choice of object pascal developers for creating cool apps across devices. The answer to this question actually depends on your situation. Pattern matching tour of scala scala documentation.
Scala is a functional language, in the sense that every function is a value. A match expression has a value, the match keyword, and at least. Composition lets revisit what we mean by composition. There currently isnt much in the way of good scala lift framework documentation, particularly for creating web forms, but i thought id share whatever good links i can find.
What this doesnt let you do is to sift through the stream and move each record into the a or b side you cant use this to separate even and odd numbers, for instance. Depending on the complexity of the page in question, this has. Scala is a modern multiparadigm programming language designed to express common programming patterns in a concise, elegant, and typesafe way. How to use wkhtmltopdf to generate pdf files from statcic. Familiar higherorder functions are implemented as methods of scala classes. Net wrapper for wkhtmltopdf dll, library that uses webkit engine to convert html pages to pdf. I was looking for a solution for this for a long time and found most of the answers are not working or not suitable for my. I have excluded these dlls in the sample code because one of the.
Take a walk through the various popular jvm languages, including java, scala, groovy, clojure, and kotlin with glimpses at exceptions, variables, and more. By continuing to use pastebin, you agree to our use of cookies as described in the cookies policy. The target audience is people who already have some experience of programming and who are familiar with the jvm. We use cookies for various purposes including analytics. Option instance is to treat it as a collection or monad and use map, flatmap, filter, or foreach val name. Open vloz opened this issue sep 18, 2012 7 comments open. Some or the object none the most idiomatic way to use an scala.
If you want to say, use play framework, you should understand that it comes with a lot of scala tooling sbt activator, integrated thirdparty libraries etc, but in the end, it pro. Net wrapper for wkhtmltopdf static dll, library that uses webkit engine to convert html pages to pdf. How to convert full webpage with css to pdf file with pechkin. Designed to be concise, many of scalas design decisions aimed to address criticisms of java. Scala functional programming patterns 2015 by atul s. Pattern matching is a mechanism for checking a value against a pattern. Scala exercises is a series of lessons and exercises created by 47 degrees.