3 ms·

the two snippets you posted do different things In a list John Jonhatan Joy searching for "Jo" returns all three of them in the first example, it stops

the two snippets you posted do different things In a list John Jonhatan Joy searching for "Jo" returns all three of them in the first example, it stops when the first has been found in the second. Start including the tedious bits about adding found items to the list and the waste of intermediate variables and your "clear" code is wrapped around a lot of repetitions, that only add noise. It just happens that you are more familiar with the second style, but pipelines are better in many other ways, clarity of intentions being one of them.

RHSeeger 5y ago
The code he posted isn't actually valid because you can't "orElse" a list. That being said, I would presume it was meant to include a "findFirst". Something like list.stream().filter(Objects::nonNull) .map(User::getUsername).filter(Objects::nonNull) .findFirst(name -> name.contains(searchString)) .map(name -> “We have found your user: “ + name) .orElse(“We haven’t found”);
- peoplefromibiza 5y ago
  exactly, that was the catch. the point I wanted to make is that the snippets presented seem carefully crafted to make pipelines look bad, but usually that's not the case.
freidenker 5y ago
The snippets actually do the same thing, as long as you add a .findFirst() to the first example to make it valid Java code. Intermediate stream operations like map or filter are always lazy. And .findFirst() is a short-circuiting terminal operation, that does not need to consume all stream elements. https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/stream/package-summary.html https://docs.oracle.com/en/java/javase/11/docs/api/java.base...
- peoplefromibiza 5y ago
  obviously that was the point, if you don't even care to write correct code, you can make every piece of code look bad. Truth is java streams and, even more, reactive java are the only two things that make java bearable, god save who invented them. If I had to program java with for loops and list.add or null checks everywhere, I would probably kill myself on the spot. But the amount of programmers taught to program like it's still 1995 it's so damn high And I am closer to my 50s than my 40s, I can't understand why people fresh from uni say they can't understand something like list.stream() .map(this::maybeGetUser) .filter(maybeUser -> userIsPresentAndNameStartsWith(maybeUser, prefix)) .findFirst() .orElseThrow(new UserNotFoundException()); with the benefit of being lazy and only inspecting list items up to the first one that matches (and if you don't mutate any data, easily parallelizable)

RHSeeger 5y ago

The code he posted isn't actually valid because you can't "orElse" a list. That being said, I would presume it was meant to include a "findFirst". Something like list.stream().filter(Objects::nonNull) .map(User::getUsername).filter(Objects::nonNull) .findFirst(name -> name.contains(searchString)) .map(name -> “We have found your user: “ + name) .orElse(“We haven’t found”);

peoplefromibiza 5y ago
exactly, that was the catch. the point I wanted to make is that the snippets presented seem carefully crafted to make pipelines look bad, but usually that's not the case.

freidenker 5y ago

The snippets actually do the same thing, as long as you add a .findFirst() to the first example to make it valid Java code. Intermediate stream operations like map or filter are always lazy. And .findFirst() is a short-circuiting terminal operation, that does not need to consume all stream elements. https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/stream/package-summary.html https://docs.oracle.com/en/java/javase/11/docs/api/java.base...

peoplefromibiza 5y ago
obviously that was the point, if you don't even care to write correct code, you can make every piece of code look bad. Truth is java streams and, even more, reactive java are the only two things that make java bearable, god save who invented them. If I had to program java with for loops and list.add or null checks everywhere, I would probably kill myself on the spot. But the amount of programmers taught to program like it's still 1995 it's so damn high And I am closer to my 50s than my 40s, I can't understand why people fresh from uni say they can't understand something like list.stream() .map(this::maybeGetUser) .filter(maybeUser -> userIsPresentAndNameStartsWith(maybeUser, prefix)) .findFirst() .orElseThrow(new UserNotFoundException()); with the benefit of being lazy and only inspecting list items up to the first one that matches (and if you don't mutate any data, easily parallelizable)