I’d like to read in a file and produce a `Set<S...

# getting-started

[Ellen Spertus]

I’d like to read in a file and produce a Set<String> containing all of the words in the file. Is there a way to map or flatMap over the lines of a file? I’ve gotten as far as bufferedReader().useLines().

[deactivateduser]

you could probably enhance from this idea.

https://play.kotlinlang.org/#eyJ2ZXJzaW9uIjoiMS4zLjYxIiwicGxhdGZvcm0iOiJqYXZhIiwiYXJncyI6IiIsImpzQ29kZSI6IiIsIm5vbmVNYXJrZXJzIjp0cnVlLCJ0aGVtZSI6ImlkZWEiLCJjb2RlIjoiLyoqXG4gKiBZb3UgY2FuIGVkaXQsIHJ1biwgYW5kIHNoYXJlIHRoaXMgY29kZS4gXG4gKiBwbGF5LmtvdGxpbmxhbmcub3JnIFxuICovXG5cbmZ1biBtYWluKCkge1xuICAgIHZhbCBteVNldCA9IFwidGhpcyBpcyBhIHRlc3Qgb2YgYSBsb25nIHdvcmQgd29yZCBsb25nIGxvbmcgdGhpcyBubyByZXBlYXRcIi5zcGxpdChcIiBcIikudG9TZXQoKVxuICAgIHByaW50bG4obXlTZXQpXG59In0=

[Ellen Spertus]

@deactivateduser Yes, I could do that with readText(). Thank you. Unfortunately, I oversimplified my problem: I need to remove lines that, when trimmed, start with #. Maybe I could see how readText() is written and write my own version.

[Ellen Spertus]

OK, I see that readLines() returns a List<String>. I can deal with that.

[deactivateduser]

Ok. If your files are big though, you might want to consider another approach, as creating a List of thousands of lines could be memory consuming.

[Ellen Spertus]

@deactivateduser Agreed, but the file isn’t huge.

[Ellen Spertus]

This seems to work. https://pl.kotl.in/RgxBdBWYM

[Ellen Spertus]

Thanks for your help, @deactivateduser! I’m the only Kotlin programmer on my team (and remote much of the time) so I don’t have anyone local to bounce ideas off of.

[deactivateduser]

no problem.. 👌

[Sebastian Aigner]

@Ellen Spertus you can even get rid of the if-else statement by using filterNot, like in this example implementation which has the same behavior: https://pl.kotl.in/nFO6cvPUU

[Ellen Spertus]

Thanks, @Sebastian Aigner!