• mbtrhcs
    link
    fedilink
    arrow-up
    3
    ·
    2 months ago

    Yeah, in Java calling first() on a stream is the same as an early return in a for-loop, where for each element all of the previous stream operations are applied first.

    So the stream operation

    cars.stream()
        .filter(c -> c.year() < 1977)
        .first()
    

    is equivalent to doing the following imperatively

    for (var car : cars) {
        if (car.year() < 1977) return car;
    }
    

    Not to mention Kotlin actually supports non-local returns in lambdas under specific circumstances, which allows for even more circumstances to be expressed with functional chaining.

    • nous@programming.dev
      link
      fedilink
      English
      arrow-up
      4
      ·
      2 months ago

      These are not quite equivalent. In terms of short-circuiting yeah they both short-circuit when they get the value. But the latter is returning from the current function and the former is not. If you add a return to that first example then they are equivalent. But then cannot be used in line. Which is a nice advantage to the former - it can be used inline with less faff as you can just assign the return to a value. The latter needs you to declare a variable, assign it and break from the loop in the if.

      Personally I quite like how the former requires less modification to work in different contexts and find it nicer to read. Though not all logic is easier to read with a stream, sometimes a good old for loop makes the code more readable. Use which ever helps you best at each point. Never blindly apply some pattern to every situation.