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.
3
votes
2answers
66 views
Custom key class for .NET 3.5 framework
I use .NET 3.5 framework, so no tuples. I have many use cases where I have to create a custom key for a dictionary. How can I make this better?
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3
votes
2answers
50 views
Most efficient dict filter on key tuple?
I have a dict wherein a value needs to be retrievable by any one of several keys. It seemed that making multiple dictionaries or multiple entries in a single ...
2
votes
1answer
64 views
Return most recent DateTime C# Entity Framework
Job -> Many Quotes
Quote -> EmailLogList
EmailLogList -> Many EmailLogs
I want to return a CreatedDate from an EmailLog which has been created most ...
4
votes
1answer
70 views
(C++14) Handling state in C-style function pointer callbacks
I'm having some issues coming up with a sensible solution for using shared state in a C-style function pointer. I am using GLFW to handle my OpenGL context and have created a thin wrapper around all ...
5
votes
2answers
187 views
Custom sorting of dates
I have implemented a class which implements a list of my custom DateObj. I have sorted the list in a peculiar manner based on the current month. I achieved my ...
3
votes
1answer
58 views
Updating all members of a struct in database
This function is part of our company's project code.
The following function updates six members of struct CpGSMTimeDelayQuery -- ...
2
votes
1answer
59 views
Writing strings to the screen over time
The following methods just write strings to the screen over time to make it look like a typing effect, instead of all at once. The only difference is the argument in the ...
1
vote
1answer
53 views
JavaFX await implementation
I'm debating trying to take a crack at getting something similar to C#'s async-co-routine like nature over on JavaFX.
This is technically feasible since the Quantem toolkit exposes the ...
4
votes
1answer
49 views
Write Once Use Everywhere: Multidimensional array traversal
I have a structure that is organized much like a Sudoku board, where individual cells reside in an n x n region, and those regions reside in an n x n area. I need to be able to address both the ...
1
vote
2answers
105 views
Read a txt file and split into 2 csvs based on regex
So I have been told that my code is not good and needs refactoring. I'm struggling to see what I need to do. How do I specify the success and failure conditions for lambda? Also don't get what the ...
1
vote
1answer
37 views
Use an optionally passed-in block without repeating yourself
I need to open and read several files for a project. Some of them are plain text files, and I just want a standard File.open to read from. One of them is an XML ...
3
votes
4answers
482 views
Checking whether a list is sorted, ascending or descending
What is the best way to conditionally use an operator? All 3 methods seemed acceptable to me, and the last 2 better.
If you're curious: I've got a list which is unsorted, and many other lists which ...
1
vote
1answer
101 views
Lambda to collect properties in a child object
I have a class:
public class ProductInvoice {
//Some other properties.
private List<ProductEntry> productEntries = newArrayList();
//otherMethods
}
...
5
votes
3answers
222 views
Filtering units by a dynamic Lambda expression
I have a simple if statement which, based on user input, determines which expression is going to be utilized. It looks like it can be done better.
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1
vote
1answer
132 views
Routing Java objects using conditional consumers
As per a previous question here and answers I got, I used it to get a new implementation. I found that I have to make two implementations match once "to ignore other consumers after matching once" and ...
12
votes
1answer
163 views
Mandelbrot Streams
A recent Mandelbrot question (Hi @EBrown) in C# inspired me to build my own using the Java 8 parallel streams to implement the parallelism that's useful for computing each pixel value.
The intention ...
4
votes
2answers
72 views
Function for timing executions (inspired by MATLAB tic toc)
Inspired by MATLAB's tic/toc I've written a short helper function for calculating execution time.
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0
votes
0answers
260 views
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 ...
10
votes
2answers
505 views
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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5
votes
3answers
299 views
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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3
votes
1answer
410 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 ...
2
votes
1answer
83 views
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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11
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6answers
3k views
3
votes
1answer
130 views
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 ...
7
votes
1answer
177 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 ...
0
votes
1answer
58 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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5
votes
2answers
3k 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 ...
5
votes
1answer
137 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 ...
11
votes
2answers
510 views
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 ...
2
votes
2answers
138 views
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 ...
2
votes
1answer
909 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 ...
7
votes
2answers
395 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 ...
12
votes
3answers
655 views
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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4
votes
1answer
861 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 ...
6
votes
4answers
18k views
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 ...
8
votes
3answers
181 views
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 ...
7
votes
2answers
1k views
5
votes
1answer
89 views
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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vote
0answers
50 views
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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vote
1answer
1k 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; ...
3
votes
2answers
391 views
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 ...
3
votes
1answer
164 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 ...
4
votes
1answer
41 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 ...
2
votes
1answer
56 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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10
votes
3answers
908 views
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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6
votes
1answer
65 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 ...
14
votes
2answers
376 views
Collatz conjecture using Java lambdas
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 called "Half Or Triple Plus ...
9
votes
1answer
759 views
Too much fun with EnumMap-related features and lambdas?
I have an utility class to handle EnumMap-related features, such as creating/converting between Object -> Enum and ...
10
votes
1answer
102 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 ...
1
vote
1answer
407 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 ...
