Unanswered Questions

26
votes
1answer
1k views

How to implement a branch-and-bound in a functional programming language?

I am trying to write a branch and bound search on the set of all functions f: D -> R, where the domain size is small (|D| ~ 20) and the range is much bigger (|R| ~ 2^20). Initially, I came up with the ...
12
votes
2answers
258 views

Does Optimistic Concurrency per object imply Serializability if a transaction will never span multiple objects?

Given a system which provides: Optimistic concurrency control / versioning per object (using CAS - Check-and-Set) Transactions that never need to span more then a single object. Snapshot Isolation ...
10
votes
1answer
136 views

Do classes in a JRE library support observable and/or asynchronous reads from external/non-JRE assemblies?

How can I implement my cross-platform library (e.g. on JRE) to operate in a thread-safe manner on object references, so that native front-ends on other platforms can observe the object and take ...
9
votes
3answers
376 views

Which data store is best for my scenario?

I'm working on an application that involves very high execution of update / select queries in the database. I have a base table (A) which will have about 500 records for an entity for a day. And for ...
9
votes
0answers
423 views

DB migration and Azure deployment slots

I'm planning to push a new web application to an Azure Web App Service (former Azure Website). I'd like to make use of the deployment slots to be able to test my deployment before pushing it to ...
9
votes
0answers
231 views

Why do Haskell functors only have derived types in their target category?

In Haskell, the Functor typeclass functor is defined as follows (see e.g. Haskell wiki): class Functor (f :: * -> *) where fmap :: (a -> b) -> f a -> f b As far as I understand ...
8
votes
0answers
112 views

Unit testing for data munging pipelines made up of one-line functions

Reading Mary Rose Cook's Practical Introduction to Functional Programming, she give as an example of an anti-pattern def format_bands(bands): for band in bands: band['country'] = 'Canada' ...
7
votes
1answer
150 views

Code Design: Delegation of arbitrary functions

On PPCG, we frequently have King of the Hill challenges, which pit different code bots against each other. We don't like limiting these challenges to a single language, so we do cross-platform ...
7
votes
0answers
114 views

Algorithm to generate Edges and Vertexes outwards from origin with max multiplicity of 3

I am creating a 2d game for a website where the universe can grow extremely large (basically infinitely large). Initially, the universe is composed of 6 stars that are an equal distance from the ...
7
votes
0answers
218 views

How do I associate command objects with the right receiver?

I tried to use Command Pattern for implementing Undo and Redo in my project public abstract class Command { protected Form Receiver { set; get; } protected HtmlElement Element { set; get; } ...
7
votes
1answer
226 views

Heuristic Approach for Flexible DIFF Implementation

I have created a DIFF implementation to compare document revisions at work. It is based on An O(ND) Difference Algorithm and Its Variations. One thing that has become important is to take the list ...
6
votes
1answer
86 views

Fuzzy algorithm for grouping data

I have data that indicates which topics each student has got right/wrong in an assessment.: | Student | Topic 1 | Topic 2 | Topic 3 | Topic 4 | Topic 5 | ... (perhaps 30 topics) | 1 | T | ...
6
votes
3answers
173 views

Best solution to authorize that a user is only allowed to modify/act with their own resources in a REST API

Background: Currently in the process of building out a REST API, using node w/express and it is consumed by a mobile app and eventually a (modern browser based) website. I'm trying to identify the ...
6
votes
1answer
116 views

Am I using Zend Form library correctly? (I am effectively duplicating work in Controller and in View)

Brief Summary This question is asking for guidance on how to deal with Zend Form library that allows me to specify how to construct each form element (Controller side) and how to render each element ...
6
votes
1answer
84 views

Strategies for investigating performance of an ASP.NET web application running under .NET 4

I'm trying to compare the performance of an application that has recently been converted from .NET2 to .NET4. From my perfomance tests it seems that although page response times are generally a bit ...

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