Tagged Questions

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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2
votes
1answer
52 views

Dealing with state

I am working on something that involves the observer pattern. A simple version of that looks like this: ...
10
votes
2answers
97 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 ...
2
votes
1answer
70 views

Ported C# scheduling to Scala - does not feel idiomatic

I'm taking a design workshop, we've received a short task which is: To parse an input file of processor jobs. To simulate scheduling of those jobs on a parallel computer (each job needs X ...
2
votes
1answer
29 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. ...
5
votes
2answers
75 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 ...
2
votes
2answers
204 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 ...
10
votes
2answers
104 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 ...
3
votes
2answers
154 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 ...
2
votes
1answer
143 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 ...
1
vote
2answers
72 views

Realizing a SQL ResultSet into a Map in Scala

I am trying to realize a java.sql.ResultSet into a map, in Scala. ...
2
votes
0answers
39 views

MySQL natural search and like search

I have written two queries for searching, but I want to simplify them as it seems needed. ...
5
votes
2answers
112 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 ...
5
votes
1answer
59 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 ...
6
votes
1answer
91 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 ...
3
votes
2answers
86 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? ...
3
votes
2answers
92 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 ...
3
votes
2answers
104 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 ...
3
votes
2answers
201 views
7
votes
3answers
206 views

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 ...
3
votes
1answer
130 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: ...
1
vote
1answer
61 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 ...
8
votes
1answer
105 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. ...
5
votes
1answer
77 views

Too many nested Types?

I have the following Scala code: ...
4
votes
3answers
72 views

Idiomatic Scala Generics

I'm working on some Scala problems given here, specifically: ...
1
vote
2answers
101 views

Finding Duplicate (Key, Value) in Map

I wrote a function for checking if a Map[(String, String)] contains an element with a matching key and value: ...
7
votes
0answers
98 views

Implementing a generic and covariant Set in Scala

I'm struggling with manually implementing a simple purely functional Set that's also generic and covariant on its type parameter: ...
4
votes
0answers
63 views

Functionally Typed I/O Streams

I thought up a function that provides types with InputStream and OutputStream: ...
2
votes
1answer
51 views

Aggregating values of a path-dependent type

I have a type representing an immutable order which contains immutable order lines that belong to it. I want to use path-dependent types for this. Obviously you cannot instantiate a path-dependent ...
10
votes
2answers
172 views

Sending SMS through twilio from play framework

I am trying to send SMS using Twilio with Scala 2.10 in Playframework 2.2, but this code is looking odd to me, maybe due to lots of conditions. I'm sure it needs some important reviews. ...
3
votes
2answers
100 views

Timing Project Euler Problem 1

Is there a better way to time the functions and print the result and function name dynamically? ...
1
vote
4answers
103 views

Transforming a list of maps representing bands

I have the following code, it takes a list of maps representing bands and transforms the band properties via the pipeline_each method. As you can see in the code, ...
2
votes
0answers
130 views

Netty-based safely network reconnection

I am writing a TCP client app using netty NettyConnectionManager.scala: ...
1
vote
0answers
40 views

Elementary foldMap implementation

I think I got the implementation right, but I'm a bit unsure if this implementation will do fine in terms of space (stack) because I'm doing a foldRight. Would I ...
3
votes
1answer
213 views

Binary search in functional-style Scala

Curious to know how I can improve it, especially the pattern matching part seems a bit repetitive at the moment (lots of case x if ds(x)) ...
3
votes
1answer
124 views

Uploading a video in S3 Using Future

I've posted a similar program previously, but I have not made any major modifications in the code, so I am posting it again by deleting the previous question. I am afraid of the thread keyword and I ...
2
votes
2answers
53 views

Branching with multiple Try

I have a series of four method calls that all return Try[Something], with the last returning Try[Unit]. Something like this: ...
3
votes
2answers
132 views

Update Immutable Map

How's the following function to update an immutable Map's values? ...
5
votes
2answers
144 views

Connecting to RabbitMQ

I would like a review for this connection to RabbitMQ. I just developed it and seems to be working well, but I would like another set of eyes on it before putting this on the sever. ...
0
votes
1answer
82 views

Updating MySQL with shuffled numbers between 1 and 50

I need to assign a number to each userId. I think this is too much of a query for updating. Is it possible to reduce the number of queries, or is it okay? ...
4
votes
3answers
221 views

Random 6 to 10 digits number

I am generating a random numerical 6-10 digit password. I need some important reviews of yours. Is it OK or are there some needed modifications? ...
6
votes
4answers
285 views

Multiple SQL queries, one per ID

ids contains 100 ids that are comma delimited. Is it fine or does it need improvement? ...
4
votes
0answers
166 views

Scala heap implementation

I'm a Scala beginner, so it'd be great if anyone would be so kind to give some feedback. ...
3
votes
1answer
149 views

Scala Tic Tac Toe Game

This is my first Scala game. I would love some feedback on my coding style, or your brief input on how you would do it. ...
5
votes
2answers
532 views

Parsing JSON to a Map and Set structure

How do I make these line of codes more scala-ish (shorter?). I still get the Java feeling in it (which I want to stay away from). ...
4
votes
1answer
84 views

Finding the longest word from a list of words

I have a list of words (with repetitions), and I intend to find out the longest words amongst them, along with their length. My question is to know if my implementation is too verbose, is using too ...
5
votes
2answers
86 views

Beginner Project: Bunny City

I am a Java programmer, and I just recently started learning Scala for fun. I found a group of projects here, and I tried to do the graduation excercise. The problem is, my code looks a lot like java, ...
4
votes
0answers
110 views

Binary Search Tree Monad Implementation

I've written a Binary Search Tree Monad in Scala. I would like to hear your thoughts on how to improve it (e.g. making insertion/deletion/search faster and more scalable). Also, is there a better way ...
3
votes
0answers
66 views
+50

VerbalExpressions in Scala

I forked the original implementation of VerbalExpressions in Scala here: https://github.com/pathikrit/ScalaVerbalExpressions I am looking forward to these things in the code review: ...
3
votes
2answers
259 views

Apache log4j in play framework

I have converted this code from Java to Scala, and I need reviews. This works fine, but I am sure that something is wrong with this coding pattern. ...
3
votes
0answers
78 views

Custom Scala implementation of generic Future.sequence

I'm trying to make sure I understand how to write clean and robust idiomatic Scala, so I wrote a custom generic implementation sequence of type ...