On 2 August 2013 22:11, Jona Christopher Sahnwaldt <[email protected]> wrote: > On 2 August 2013 11:52, Hady elsahar <[email protected]> wrote: >>> Scala uses implicit conversions, so instead of the explicit conversion >>> new RichFile(...) you can just import a method that does that >>> conversion and is declared as implicit. In this case, >>> RichReader.wrapReader. >>> >>> You can basically replace the three lines of >>> code above by one import and one statement: >>> >>> import org.dbpedia.extraction.util.RichReader.wrapReader >>> >>> IOUtils.readLines(file) { line => >>> ... >>> } >>> >>> As another cosmetic change, you could also import IOUtils.readLines: >>> >>> import org.dbpedia.extraction.util.IOUtils.readLines >>> import org.dbpedia.extraction.util.RichReader.wrapReader >>> >>> readLines(file) { line => >>> ... >>> } >> >> >> done that >> https://github.com/hadyelsahar/extraction-framework/blob/lang-link-extract/scripts/src/main/scala/org/dbpedia/extraction/scripts/LanguageSpecificLinksGenerator.scala >> >> except for in the second option "generating specific files" , i wanted to >> trigger the last line of code so i needed the method "hasNext" , so i >> couldn't use readlines defined method in IOUtils >> >> val inFile = new File(args(1)) >> val inStream= IOUtils.inputStream(inFile) >> val lines = Source.fromInputStream(inStream).getLines >> >> don't know , maybe we could add this to the functionality of IOUtils , i > > I see. You are right, the current implementation of readLines makes > that very difficult. > > There's an easy fix: RichReader.foreach [1] could use null as the > value of the last line, just like the BufferedReader it wraps. Simply > change these lines: > > if (line == null) return > proc(line) > > to this: > > proc(line) > if (line == null) return > > Of course, this is a breaking change, and we have to modify all the > code that uses IOUtils.readLines or RichReader.foreach to check for > null. > > Or maybe we should change the signature of > > (proc: String => U) > > to > > (proc: Option[String] => U) > > and use None instead of null for the last line. Yeah, I guess that's > the Scala way. It also means that the code currently using readLines > and foreach won't compile anymore. Which is good.
I implemented the first solution (last value is null): https://github.com/dbpedia/extraction-framework/commit/c8d2f8b61b6bd868cbdc7b78f2ca28253bd4acd5 It's on the dump branch, but I guess you can copy it over or so. I tried the Option[String] solution first, but I found that I had to make more intrusive changes to the existing code. And in general, I often find Scala's match/case structures less readable than if-then-else. For example, in your case, you probably need to handle the case line == null in the same code block as the case line != null, so you can hardly use match/case. But I may be wrong, I'm not a Scala expert. JC > > > JC > > > > [1] > https://github.com/dbpedia/extraction-framework/blob/dump/core/src/main/scala/org/dbpedia/extraction/util/RichReader.scala > >> suggest also adding function WriteLine to IOUtils , to use it instead of >> LogtoFile method that i implemented >> >> >> >>> I just searched for introductions to Scala implicits, and I think this >>> one is pretty good: >>> >>> http://www.artima.com/pins1ed/implicit-conversions-and-parameters.html >> >> >> thanks for the link , it's good >> >> >> thanks >> Regards >> >> ------------------------------------------------- >> Hady El-Sahar >> Research Assistant >> Center of Informatics Sciences | Nile University >> ------------------------------------------------------------------------------ Get your SQL database under version control now! Version control is standard for application code, but databases havent caught up. So what steps can you take to put your SQL databases under version control? Why should you start doing it? Read more to find out. http://pubads.g.doubleclick.net/gampad/clk?id=49501711&iu=/4140/ostg.clktrk _______________________________________________ Dbpedia-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dbpedia-developers
