Scala is a general purpose programming language principally targeting the Java Virtual Machine. Designed to express common programming patterns in a concise, elegant, and type-safe way, it fuses both imperative and functional programming styles.

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File-to-fully qualified class name function

My instincts are telling me a seasoned Scala programmer will find my code less than optimal. As will no doubt be obvious, I'm a Java guy who has just started in with Scala. Is there a more ...
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NonEmptySortedSet implementation

I'm looking for feedback specifically about what I might add to this to make it more usable or general, especially with regard to scala collection traits to implement. ...
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47 views

Extracting tuples from Excel sheet

My code have too much nested option processing which makes it ugly. But it has an advantage it has no side effect and typesafe. ...
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58 views

Test runner for Scala problems

I'm learning Scala and could use another set of eyes on the code below. I'm creating a test runner for the 99 scala problems set. I figure between actually solving the problems and working through the ...
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Using Java's Fork/Join library from Scala

I am a newbie trying to learn some Java and I am reading prof. Dan Grossman's introductory lecture notes on parallel and concurrent algorithms. I wrote a version of a divide-and-conquer algorithm for ...
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95 views

BFS Maze Solver in Scala

I recently got a Scala developer position, so I'd like to get more comfortable with Scala on my own. Here is a maze solver that I wrote (previously in other languages) that I translated to Scala. Any ...
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18 views

Gathering response from a pagable service

I'm wondering how this code could be improved. I especially don't like the use of mutable Buffer but not sure what the best way to get it out cleanly. ...
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30 views

Scala TryWith that closes resources automatically

I'm quite new to Scala and was surprised that there doesn't seem to be anything like Java's try-with-resources block. So of course I wrote my own little construct. Is there anything I could improve? ...
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1answer
55 views

Async Controller Play 2.3

Is this example the correct way of writing an Async controller end point in Scala using Play 2.3? ...
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49 views

Tail Recursive Fibonacci

Please critique my implementation of a tail-recursive method for generating the Fibonacci sequence: ...
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23 views

A Timer Construct to Simplify Timing Blocks of Code

This is fairly simple, so I'm just looking for ideas on anything that can be cleaned up, places it can be extended, and suggestions regarding style/naming (I'm terrible at naming). It allows you to ...
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225 views

API for looking up Japanese postal code

Most of my experience is in Python, Java and embedded C, and I need to learn Scala and Play for a new job. As an exercise, I decided to create a very simple API for looking up area by postal code, ...
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41 views

A Simple Thread Pool in Scala

I wrote the following that spawns n threads, uses them to process a queue of jobs, then returns a result. As well as any general suggestions, I'd like feedback on the following: How safe is ...
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18 views

Gathering emails, phones, URIs, and tag related to a room

I've made a strange method with multiples conditionals, creating a lot of Lists and I was wondering if I could write it in a better and more legible way. ...
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“Functionalizing” this tree walking method and cleaning it up

I have a MessageTree class that represents a binary tree of negative/positive. I'm looking to improve my walkTree method and ...
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2answers
67 views

List.containsSlice

In an effort to strengthen my functional programming, I'm reading Functional Programming in Scala. One of the assignments is to implement a function that does the same operation as ...
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3answers
66 views

Refactor jaccard similarity the “Scala way”

I'm trying to pick Scala up. This is a simple heuristic that checks a similarity value between two sets. I've done this a million times in Java or Python. The function works, but I'm certain I am not ...
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60 views

A simple “Tamagotchi” like game that uses math questions as food

I wrote a Tamagotchi-like game where to feed the pet, you do math questions instead of just pressing a button. It's persistent, in that on loading, it figures out long it's been since the last save, ...
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189 views

Checking for balanced parentheses

I wrote a method to check if each parenthesis in a string is closed. It should take into account the order in which a parenthesis is presented, e.g. "hello)goodbye(" should return false even though ...
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Scala BitSet implemented with Java BitSet, for use in Scala Enumerations to replace ValueSet

Due to a performance profiling hot spot detailed in http://stackoverflow.com/questions/27632554/scala-enumeration-valueset-slow-replacement-based-on-java-bitset , I implemented my own BitSet using ...
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Oh ye beloved bejeweled

Before @bazola asked his recent question we chatted about it for a bit. I figured that I could try implementing something similar myself. As I've heard that Scala has all the advantages of Java but ...
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60 views

Scala Case Classes

Please take a look at the following Scala program and give me suggestions for improvement. I'm sure there would be plenty. This is my very first Scala code, so please don't be frustrated because of ...
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101 views

A Cipher with 2 methods for encryption/decryption

I'd like advice on how this could be written more efficiently, idiomatically, or just anything that could be improved upon. I'd also like to know if there's an alternative to my ...
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78 views

Idiomatic Scala for nested map/flatmap

Does anybody have an idea on how to make this code more idiomatic? I tried to use scalaz Traverse, but it didn't really help. Given the types and method signatures: ...
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102 views

First four Project Euler in Scala

I was working on teaching myself some Scala and decided to tackle some Project Euler problems. The first four of these turned out to be one liners. ...
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71 views

Generating a game board with squares in a rectangle

I am trying to generate a game board (similar to a Monopoly board). I am new to Scala and am thinking that there may be a better way to do this. But improvements to the code are also welcome. ...
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85 views

zipWith function in Scala

My implementation works, but it looks very ugly. Curious to see how it's better implemented. The zipWith function takes a list of lists (...
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3answers
70 views

Removing nested blocks from a string

I wrote this function in scala that uses tail recursion to remove nested blocks from a text. Usage examples: ...
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1answer
63 views

Dealing with state

I am working on something that involves the observer pattern. A simple version of that looks like this: ...
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158 views

“Pure” functional simple Scala battle game simulation

I am a long time imperative programmer (mostly C++) taking my first forays into functional programming with Scala. I am following some online tutorials about functional programming and Scala and I'm ...
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86 views

Ported C# scheduling to Scala

I'm taking a design workshop and we've received a short task: To parse an input file of processor jobs. To simulate scheduling of those jobs on a parallel computer (each job needs X processors) The ...
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36 views

Access case class parameter inside a map with default [closed]

I have a map whose values are case classes, and I want to access one parameter of that case class with a default value if they map doesn't contain the provided key. ...
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138 views

Simple search engine using TF-IDF (200 LOC)

I wrote simple search engine based on TF-IDF statistic and cosine similarity. I am still learning Scala, so would be glad to hear comments (here or at GitHub) regarding my code from Scala ...
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230 views

Comparing equivalent Scala and C# string-manipulation code - with Scala running much slower

I am very early in my journey of learning Scala, and I was doing challenges on hackerrank.com to get used to the syntax. As I finished one (very trivial) challenge, I noticed that the run times seem ...
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111 views

Value Mapper service

I have some data I'm getting from an external source that I don't control and have been told that I have to map some of it to "user friendly" display values. So I wrote a little utility service to do ...
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2answers
172 views

Removing asInstance[T] from scala code

I've written this scala code and I cannot work out how/if it is possible to remove the asInstance in the definition of class ...
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1answer
287 views

Distributing workload using Akka Router with exception handling

I am fairly new to Akka and I am interested in any feedback about the following code. Is this the correct way to go about distributing workload across a number of threads? Do I use the Akka API ...
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221 views

Realizing a SQL ResultSet into a Map in Scala

I am trying to realize a java.sql.ResultSet into a map, in Scala. ...
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43 views

MySQL natural search and like search

I have written two queries for searching, but I want to simplify them as it seems needed. ...
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139 views

Project Euler #17

Project Euler presents problem 17: If the numbers 1 to 5 are written out in words: one, two, three, four, five, then there are 3 + 3 + 5 + 4 + 4 = 19 letters used in total. If all the ...
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72 views

Dictionary synonym lookup via networking

I have a small TCP service running on port 4444 which, given a word, will look up synonyms in a dictionary. Below is my Scala code for connecting to the socket, sending the lookup command and parsing ...
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133 views

BFS and DFS tree traversal

I posted some code as part of an answer to another question and I thought it would be a good idea to get that code reviewed also. Any comments are welcomed, but I am mostly annoyed by ...
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2answers
144 views

BFS tree traversal Scala

I would love some feedback on the following code for BFS traversal in a binary tree. Is there a cleaner way to write this? ...
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2answers
111 views

Cleaning up file resources in a DRY manner

I've written a function that generates a report, and then sends it as an attachment to an email. I don't want to clutter the function with a lot of calls to close up the filesystem, if there was an ...
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2answers
122 views

Hamiltonian Monte Carlo in Scala

I'm writing a program in Scala to perform Hamiltonian Monte Carlo (HMC), coupled with Gibbs sampling of some variables. The algorithm, with the modifications such as perturbing epsilon and l and ...
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226 views
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Reducing boilerplate when validating parameters and using a tuple for the parameter list of a case class

I had designed a simple case class that looks like this: case class StreetSecondary(designator: String, value: Option[String]) I needed to add validation (to ...
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1answer
202 views

Writing a new Finagle protocol

The following is a fairly naive implementation of a Finagle protocol that uses the scodec library for binary encoding and decoding. I'll assume something like the following SBT setup: ...
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64 views

Combinations with replacement

I am still new to Scala and wrote a small snippet to find all the combinations with replacement of a sequence (e.g. cwr(ab, 3) should give aaa, aab, abb, bbb). The slow way would be to generate all ...
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114 views

Dungeon generation in Scala

I've recently begun learning Scala, and while I've run into its concepts before (immutability, tuples, first-class functions) I'm not sure whether I'm using the language how it's supposed to be used. ...