Functors, applicatives, and monads in pictures

Re:Functors, applicatives, and monads in pictures by chongli on Sunday May 19, 2013 @05:57PM (#5734570)

Recursion is how you implement a sum without mutation (an imperative loop is how you'd implement it with mutation). You've merely given me the function written in a declarative notation.

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Re:Functors, applicatives, and monads in pictures by Gravityloss on Tuesday May 21, 2013 @11:54AM (#5744509)

I think we are talking about different things.

For example, if you integrate x^2 dx from x=0 to 10, x changes continuously.

It's clear that x is not fixed to any particular value.

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Re:Functors, applicatives, and monads in pictures by chongli on Wednesday May 29, 2013 @05:32AM (#5785400)

Yeah, you're talking about the mathematical definition of a bound variable. Functional programming languages use this whenever you define a function:

   foo x = x * 2

Every time you call foo, x is bound to a new value (but only within the scope of foo). This is not the same as mutating some memory location associated with the name x.

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