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JVM Languages

Constructors in Ceylon

Since the earliest versions of Ceylon, we’ve supported a streamlined syntax for class initialization where the parameters of a class are listed right after the class name, and initialization logic goes directly in the body of the class. class Color(shared Integer rgba) { assert (0 <= rgba <= #FFFFFFFF); function encodedValue(Integer slot) => rgba.rightLogicalShift(8*slot).and(#FF); shared Integer alpha => encodedValue(3); shared ...

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Scala Days: 11 of the Best Speakers Share Their Slides

The slides behind some of the best talks at Scala Days Scala Days Amsterdam has swept us with tons of awesome Scala content, we had a great time attending the talks and showcasing Takipi’s new reactive monitoring solution. There were a total of 55 different sessions around all things Scala and some of the slides have already started popping up. ...

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Geb Gems: Handling AJAX requests

One of the biggest struggles while testing web applications that use AJAX is dealing with the timing issues caused by asynchronous nature of the request. A common solution is using timeouts to wait for the AJAX call to be completed. This could cause lots of timing issues. Using Geb there is a better way to determine that the AJAX call and its ...

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Programming with type functions in Ceylon

I’ve recently been working on some experimental new features of Ceylon’s already extremely powerful type system. What I’m going to explain in this post is known, technically, as: higher order generic types (or type constructor polymorphism, or higher kinds), and higher rank generic types (or rank-N polymorphism). Please don’t worry about this jargon salad. (And please don’t try to google ...

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Backpressure in action with websockets and akka-streams

So in the previous article I showed how you could create a websocket server using akka-streams. In this follow up article we’ll look a bit closer on how backpressure works with websockets (and probably any TCP based protocol on top of akka). To show you this we’ll use the same setup as we did in the article on visualizing backpressure. ...

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Using separate Postgres Schemas for the same database in a Grails App

Recently, I wanted to use the same Postgres Database but split my persistence layer into separate components which used separate schemas. The motivation was to promote modular design, separate concerns and stop developers tripping up over each other. Vertical domain models can be difficult to achieve but not impossible. In my shopping application, I had a user component, a shopping ...

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Neo4j: The BBC Champions League graph

A couple of weekends ago I started scraping the BBC live text feed of the Bayern Munich/Barcelona match, initially starting out with just the fouls and building the foul graph. I’ve spent a bit more time on it since then and have managed to model several other events as well including attempts, goals, cards and free kicks. I started doing ...

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Groovier Spring Boot Integration Testing


Recently I had a chance to use Groovy’s groovy.json.JsonSlurper in a soapUI REST project. The usage scenario in soapUI (in particular, soapUI Open Source) was very simple: in a Groovy assertion, load the content of a response into a variable and than verify it like this: import groovy.json.JsonSlurper; def slurper = new JsonSlurper() def result = slurper.parseText(messageExchange.responseContent) assert result.incidentType == ...

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Grails’ JSONObject.NULL More or Less Equal To Null

Since Groovy 1.8 we can check if a Map is equal to another Map if the keys and values are the same. Very convenient in tests for example. def someMap = [age: 34, name: "Ted"] assert someMap == [name: "Ted", age: 34] Today I kept staring at a failure, while testing some x and y graph data points returned by ...

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