re: Tell us what your top unpopular tech opinion is 😈 VIEW POST

re: The promise of functional programming rarely matches reality. Some of the supposed benefits of it are that programs are more concise and easier to ...

I think strict functional programming in Javascript doesn't make sense. The lack of built-in currying and parentheses on function calls makes it awkward to write functional code. But, I think applying some ideas from it is useful. The most helpful thing I take from fp in Javascript is keeping functions as pure as possible. I don't mean not using for loops and mutability inside the function, but from the outside, nothing gets changed. Like returning a new array instead of modifying the one passed to it.


Yeah, I agree. Writing pure functions and making an explicit choice to introduce a side-effect is a good concept/practice to incorporate into any code. I also like the ideas of immutability and referential transparency, since those are widely applicable.

referential transparency

Well, today I learned. "This set of functional expressions is referentially transparent" seems like yet another way of saying "this bit o' code has got no side effects," but with more syllables!

More syllables is always better.

Referential transparency actually means that the reference of an object doesn't matter. Only the value is important. That basically means that even items in different places in memory that have the same value are considered the same.

Actually, according to Willard Quine[1], "a mode of containment φ is referentially transparent if, whenever an occurrence of a singular term t is purely referential in a term or sentence ψ(t), it is purely referential also in the containing term or sentence φ(ψ(t))," as in the following example:

(12) Ralph believes that the man in the brown hat is a spy.
(13) Ralph does not believe that the man seen at the beach is a spy.
The main in the blue hat = the man seen at the beach = Bernie Sanders
t = ‘the man in the blue hat’
ψ(t) = ‘the man in the blue hat is a spy’
ϕ(ψ(t)) = ‘Ralph believes that the man in the blue hat is a spy’.

I need to get more practice drawing lil tridents on whiteboards.

[1]Although ultimately, like many obtuse concepts in CS, we can safely blame Whitehead and Bertram.

Hmm, well I was talking about referential transparency as it relates to functional programming, as opposed to logic, I guess. I hadn't seen that definition before, it's pretty interesting.

code of conduct - report abuse