Questions tagged [lambda]
DO NOT USE FOR THE AWS SERVICE (use [aws-lambda] for those questions!) Lambdas are anonymous functions or closures in programming languages such as Lisp, C#, C++, Lua, Python, Ruby, JavaScript, Java, Excel or Google sheets. (Also, lambda expression.)
lambda
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Inaccurate compile-time computation of Fibonacci sequence in a recursive lambda
Below is a recursive lambda expression that can compute the values of Fibonacci sequence both in runtime and during constant evaluation:
auto fib = [](this auto && f, auto && p) {
...
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Is it possible to type hint a lambda function?
Currently, in Python, a function's parameters and return types can be type hinted as follows:
def func(var1: str, var2: str) -> int:
return var1.index(var2)
Which indicates that the function ...
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Read Large JSON File and Flatten Lambda
I have a lambda function that reads in a json file and flattens it so that I can convert it to parquet and it'll be easier to read the data. The issue I'm having is that some of the files are too ...
- 67
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AWS Lambda python log file is not created
I have a Python AWS lambda with a logger that generates two different log files:
LOG = f"/tmp/{uuid.uuid1()}_log.log"
SLOW_LOG = f"/tmp/{uuid.uuid1()}_slow.log"
logging....
- 616
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Serverless AWS Access-Control-Allow-Headers in preflight response
For some reasom this error appears from nowhere:
has been blocked by CORS policy: Request header field x-company-id is not allowed by Access-Control-Allow-Headers in preflight response.
Here is my ...
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Why would one write a C++ lambda with a name so it can be called from somewhere?
Why would one write a C++ lambda with a name so it can be called from somewhere? Would that not defeat the very purpose of a lambda? Is it better to write a function instead there? If not, why? Would ...
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Java8 How to convert 3-level nested list into nested HashMap using stream and lambda
I'm trying to convert a 3 level nested list into Nested HashMap.
The function declaration for the same is:
Map<Key1, Map<Key2, List<String>>> transformToMap (List<Obj1> ...
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Why is static lambda constructed more than once in cpp? [duplicate]
Run this code:
#include <iostream>
void Func(size_t i) {
static auto lambda = [&i]() {
std::cout << i << std::endl;
};
lambda();
}
int main() {
for (...
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4
answers
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Java 8: How to write lambda stream to work with JSONArray? [duplicate]
I'm very new to Java 8 lambdas and stuff. I want to write a lambda function that takes a JSONArray, goes over its JSONObjects and creates a list of values of certain field.
For example, a function ...
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Predicates and functions
public static void main(String[] args) {
List<String> strings = Arrays.asList("a", "b", "c", "d");
strings.stream()
.filter(s -> ...
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Does the C++ standard library have function types that are non-copy-constructible?
I want to pass a bunch of lambdas around without having to make copies.
This is the declaration of one of the lambdas
[
promise = std::move(promise),
namedSeries = std::move(namedSeries)
] ...
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votes
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answers
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How does lambda function work with reduce function in python?
I'm trying to understand the following code:
>>> print(reduce(lambda x, y: x + y, [1,2,3,4,5]))
15
What is x and y? Which is the accumulator here? Does the accumulator always has to be the ...
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lambda function of another function but force fixed argument
I just switched to Python from Matlab, and I want to use lambda function to map function f1(x,y) with multiple arguments to one argument function f2(x) for optimization.
I want that when I map the ...
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Clarity on Java Lambda Syntax [duplicate]
From my understanding, this is a single statement in Java:
while((x % p == 0l) && (x > p)) x /= p;
If that is the case, why is this a syntax error:
final AtomicLong subtotal = new ...
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Is there a reason for C#'s reuse of the variable in a foreach?
When using lambda expressions or anonymous methods in C#, we have to be wary of the access to modified closure pitfall. For example:
foreach (var s in strings)
{
query = query.Where(i => i.Prop ...
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