functional-programming Archives - Page 3 of 6

How can you do anything useful without mutable state?

I’ve been reading a lot of stuff about functional programming lately, and I can understand most of it, but the one thing I ...

May 17, 2022
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Abusing the algebra of algebraic data types – why does this work?

The ‘algebraic’ expression for algebraic data types looks very suggestive to someone with a background in mathematics. Let me try to explain what ...

May 16, 2022
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What is referential transparency?

What does the term referential transparency mean? I’ve heard it described as “it means you can replace equals with equals” but this seems ...

May 15, 2022
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Why isn’t Python very good for functional programming? [closed]

Closed. This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be ...

May 14, 2022
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How to call reduce on an array of objects to sum their properties?

Say I want to sum a.x for each element in arr. arr =...

May 14, 2022
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Functional style of Java 8’s Optional.ifPresent and if-not-Present?

In Java 8, I want to do something to an Optional object if it is present, and do another thing if it is ...

May 13, 2022
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What is Scala’s yield?

I understand Ruby and Python’s yield. What does Scala’s yield do? 10 Answers 10

May 13, 2022
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Why functional languages? [closed]

Closed. This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so ...

May 12, 2022
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What does “coalgebra” mean in the context of programming?

I have heard the term “coalgebras” several times in functional programming and PLT circles, especially when the discussion is about objects, comonads, lenses, ...

May 12, 2022
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How to use filter, map, and reduce in Python 3

filter, map, and reduce work perfectly in Python 2. Here is an example: >>> def f(x): return x % 2 != 0 and ...

May 11, 2022
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