>I think clojure helps with the speed of allocating new immutable structures by using copy on write strategies behind the scenes.
No, it's not copy on write in the sense that COW means in other languages. Data in clojure is persistent, so usually even an altered piece of data is not actually copied, only the tiny bit that changed is added, if necessary. This is very different than, for example, Swift that implements copy on write, but the whole data structure is copied even if the change is minor.
Additionally, you say:
>When we're dealing with sequential tasks, mutating data is much faster than allocating new data structures
That would be true in cases where the entire data piece is new; but so much of what you do in any language involves interative changes over existing data, and again because of clojure's persistence, new allocations are often not happening at all in many cases.
...However, I do agree with most of your other points :)
That part about speed was more about my general frustration with the "immutable is fast" and "mutable is slow" meme that I hear too frequently. While that can be the case, it isn't always 100% true. Your language and how you use it can play a huge part.
I'm hoping to learn more about clojure data structures in the coming months, so much good stuff.
My guess would be that immutable clojure is still faster than say mutable ruby though.
I don't think anybody is arguing that trie lookup is faster than array lookup.
But when it comes to passing data between parts of the system, zero cost copies are much faster than copying buffers or objects.
No, it's not copy on write in the sense that COW means in other languages. Data in clojure is persistent, so usually even an altered piece of data is not actually copied, only the tiny bit that changed is added, if necessary. This is very different than, for example, Swift that implements copy on write, but the whole data structure is copied even if the change is minor.
Additionally, you say:
>When we're dealing with sequential tasks, mutating data is much faster than allocating new data structures
That would be true in cases where the entire data piece is new; but so much of what you do in any language involves interative changes over existing data, and again because of clojure's persistence, new allocations are often not happening at all in many cases.
...However, I do agree with most of your other points :)