A lambda is an expression that acts as an anonymous function. Use this tag if you would like to discuss the appropriateness of a lambda or anonymous function in your code.
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Generic method to pass lambda expressions performed on DTO's to Entity Framework
The following are generic methods that I use to perform lambda queries on DTO objects. The main method applies the expression to entities and returns DTO objects mapped from the entities (entities ...
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Return lambda expression based on parameters
This function returns a lambda expression based on the parameters sent. I am sure there is a better way to do this.
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3answers
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Duplicate words in a text
Here is a simplified implementation to obtain the duplicate words in a text using lambda expressions.
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1answer
82 views
Event-listener implementation
While writing a C++ GUI application more or less from scratch I needed some form of an event-listener system, preferably using lambdas. An event should be able to have multiple listeners and the user ...
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1answer
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Sort files by the type of file
I need to sort files by the type of the File. To accomplish the task I first wrote the code below:
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6answers
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Catch all checked exceptions and turn into unchecked exception
I am currently trying to learn Lambdas and following the book Java SE8 for the really Impatient and just finished Chapter 1 of it. This is the question, I am trying to get done with:
Didn’t you ...
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1answer
100 views
Proper checked exception handling with lambda functions
I'm having trouble finding a clean way to handle checked exceptions thrown by a lambda function passed as a parameter in Java.
I'm writing a Client which will interact via RMI with a Server to play a ...
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1answer
53 views
Repetitive code for a projected field in a lambda
I have a simple projection in my code. Taking away the majority of the fields which are not of interest, it looks like the following:
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2answers
679 views
Optimize method to iterate to over Map<String, List<Object>>
I have a Map<String, List<Object>> multiFieldMap and I need to iterate over its value set and add the value to ...
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1answer
121 views
Multiple functions to establish a fallback value for a property until not null
I have a property (called "Head") that can be set externally. When "Head" is not set, it uses Unity3D's MonoBehaviour functions to try to find the best value for ...
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2answers
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Printing removed items using lambdas and streams
I'm struggling to make my lambdas readable.
I've seen various approaches. Below are three different examples that all do the same thing.
Forgive the example: I suspect there are better actual ...
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2answers
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Comparing triangles using Java 8 streams
I'm trying to get more familiar with Java 8 streams as they seem to be very powerful (and shorter), so I rewrote a method to use streams. However I'm not very satisfied with it and would like some ...
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1answer
317 views
Asynchronous connect() with one function call, using C++11 lambdas and Boost.Asio
I've wanted to write a C++11 class for making IPv4 TCP connections and figured that it probably could be done with just one static function using some shared_ptr and lambda "magic". The following code ...
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2answers
225 views
Simple calculator implemented with lambdas
I was searching for a way to exercise the Java 8 concepts I've been learning, especially pertaining to Lambdas. Incidentally, I hadn't used any swing in a while and wanted a refresher. This is the ...
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3answers
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The Beauty and the Strings
This originally appeared in Facebook's hacker cup 2013. Solving it was fun, though I find myself looping through similar data quite often.
Challenge:
Print the maximum beauty of strings.
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1answer
225 views
Java 8 CompletableFuture - fan out implementation
I was wondering what is the best way to implement a fan out type of functionality with Java 8 Completable future. I recently rewrote a function that had a bunch of old ...
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4answers
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Using LINQ or Lambda instead of nested and multiple foreach statements
I want to use a better syntax than nested foreach statements to overwrite the initial list with items from the second list.
In the code below:
I want to ...
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3answers
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Sending duplicate to heaven with Java 8
Follow up to Duplicate like a weapon, arrays like heaven.
@rolfl suggested in chat that I try to complete this challenge again in a Java 8 friendly way. I took the opportunity to also employ the ...
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2answers
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1answer
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Effective use of branch prediction in terrain generator
I am trying to learn how branch optimization works.
For an experiment, I have a recursive fractal terrain generation and I have moved all if statements to binary ...
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0answers
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Parallel for loop in Java - follow-up 2
The previous iteration at Parallel for loop in Java 8 - follow-up.
The changes are as follows:
MyTask is removed.
Synchronization removed. Now the user is ...
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1answer
604 views
Parallel for loop in Java 8 - follow-up
The previous and initial iteration at Parallel for loop in Java 8.
Changes are as follows:
ParallelLoopBody removed; ...
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2answers
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Parallel for loop in Java 8
This is my first attempt to provide some syntactic sugar for doing mutually independent loop iterations in parallel. Thanks to Java 8 lambdas, I can write the parallel loops in pretty elegant fashion ...
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1answer
146 views
How can I avoid repeated code using lambdas?
I have a method which should accept a Function/Action and do something with that method (in my case I've added retry logic).
I'm wondering how I can remove the duplicated code (for loop, etc) from ...
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1answer
36 views
Generic Timing Class - Follow Up
I wrote a class which can time and compare functions.
I already posted it here once before, and got great suggestions from @rolfl, which I have added to my code.
my original question can be found ...
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1answer
54 views
Conditional statements with doctor and patient information
I'm focusing on trying to write clean, modular Python 2.7.5 code.
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3answers
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Displaying information about people from a JSON file
I'm working with Python 2.7.5 and I have written the following code:
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1answer
60 views
Generic Timing Class
I have written a class which can time functions, and I'd like to have it reviewed. I'm interested in everything (better naming and commenting, accuracy of measurement, usability, structure, use of ...
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2answers
301 views
Collatz conjecture using Java lambdas
From the Wikipedia article:
Take any natural number n. If n is even, divide it by 2 to get n / 2. If n is odd, multiply it by 3 and add 1 to obtain 3*n* + 1. Repeat the process (which has been ...
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1answer
473 views
Too much fun with EnumMap-related features and lambdas?
I have created an utilities class to handle certain EnumMap-related features, such as creating and converting between ...
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1answer
93 views
Shady Characters
As part of my familiarization with the features of Java 8, and inspired by this question, I thought I would take the 'Shady Character' problem to 'the next level'.
The basic problem is that you have ...
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1answer
265 views
Group by two lists in one map using lambda
I've got two collections: collection of rules, and collection of keys that can handle specific rules. Key have method ...
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1answer
211 views
Pokemon Type Evaluator part 2
I started anew and completely refactored the way I implemented Pokemon Type Evaluator.
Also, first use of a lambda expression (Case of using it, but still don't fully grasp how it's working). I'm ...
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2answers
188 views
A method that generates a Comparator<String> using lambda expression
Given below is an exercise from the book *Java SE 8 for the Really Impatient( by Cay S. Horstmann:
Write a method that generates a Comparator that can be normal or
reversed, case-sensitive or ...
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1answer
410 views
Is there better way to shorten this Lambda expression's result selector?
I'm new in LINQ and Lambda expression. I'm not sure is there a way to shorten the result on this o.z.cust.cust.cust.bintAccountNo. As you can see below, the more ...
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1answer
896 views
EF6-Lambda Expressions deep big-tree query
I am looking to improve the following query.
We are using EF6 (CodeFirst) and C# Lambda Expressions, and Repository/Unit of Work patterns. Also, we needed to restrict the query in a way that we ...
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2answers
670 views
Platform independant thread pool v3
This is a continuation of this question, v4 can be found here
Taking the advise given previously, the deadlock was fixed in the non-yielding code. The next problem comes from the suggestion to make ...
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1answer
275 views
Refactor Oracle Entity Framework lambda query
I had a ugly problem and wrote an ugly query.
Query creates a cache that is used to get person id when I have {full_name, id_code?, birth_date?}. By question mark I mean that it is perfectly valid ...
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1answer
443 views
Exception handling with expression lambda in Presenter class
Following is a code snippet from MVP Win Forms application.
My DAL doesn't handle exceptions and it will be propagated up to the calling method in the presenter classes where the exception will be ...
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3answers
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Boost::range::for_each + functor
I would like your comments on my code in C++ (C++98 + Boost)
I have written some code to use the functors with the boost::range::for_each algorithm.
My main ...
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2answers
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Validate fields in Python dictionary using dictionary of lambdas
I would love some feedback on this. I use it to validate web-form objects before persisting them in the dangerously-lazy MongoDb. I have a class and many validators for each of my collections. Is ...
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1answer
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Sum(), ForEach() with Lambda in a hierarchical List Collection
I have to list the number of documents related to items in a hierarchical tree.
The specification states:
The tree will only ever be 2 levels deep.
The higher level items will list not only the ...
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1answer
286 views
Python Dictionary Black Magic
I am defining a subclass of a the python dictionary object mpCmd where every item is converted to a lambda. The intended usage is that every item in the dictionary ...
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2answers
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Mixing Linq queries and Linq lambdas
I have been given a change to rewrite an old framework we use, and to implement the repository and unit of work patterns, but in an attempt to not rewriting all queries I have ended up with a weird ...
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6answers
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Increment up the build number in AssemblyInfo.cs on every build
I just wrote this short little program to increment up the build number for my projects every time I build them.
After compiling this exe, I just call it in the pre-build command line.
I did take ...
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2answers
661 views
Dynamically call lambda based on stream input
Some context: I have code that looks like this (minor issue noted here):
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3answers
4k views
Effective use of multiple streams
I am experimenting with streams and lambdas in Java 8. This is my first serious foray using functional programming concepts; I'd like a critique on this code.
This code finds the Cartesian product of ...
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3answers
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Basic Rock-Paper-Scissors implementation
I decided to try to make a simple RPS implementation in Java 8, the following notes should be said first:
At a later point it should support RPSLS aswell, as any other Gesture-game variant.
At a ...
