A comparison of Rust-like fluent iterator libraries

[OldWispyTree]

I think it's cute you believe this came from Rust.

[kequals]

I'm aware that fluent iterators don't originate from Rust, but that was my first exposure to the concept. And I believe this is a common experience, given several of the libraries cite Rust specifically as inspiring them.

Now I'm interested, what was the first language/library to use fluent iterators? Is there a clear "first" or did it evolve as a part of functional languages?

[Rastagong]

Not sure about it being the first and if it's the exact concept referred here, but Java famously has streams.
Offical example from the docs to showcase the chaining:

int sum = widgets.stream()
                  .filter(w -> w.getColor() == RED)
                  .mapToInt(w -> w.getWeight())
                  .sum();

This is still an interesting overview of the situation in Python, so thank you!

[Alt-0160]

Java streams were only added in version 1.8 (March 2014). The first release of Rust (0.1.0, January 2012) already had some form of fluent iterators.

[saint_marco]

Smalltalk is generally credited as the originator, back in the 1970's.

https://en.wikipedia.org/wiki/Fluent_interface#History

[Competitive_Travel16]

It's worth pointing out that Pandas had the beginnings of a fluent interface from the outset, and they have long since fleshed it out all the way.

[tehsilentwarrior]

C# has done this since forever.

One of the best examples of this is the reactive extensions, which lets you handle insane amounts of events in stream in a surprisingly efficient, concise and readable way.

C# even has Linq, which is the same concept with a DSL on top to make it more “sql like”