Crazy Scala Combinator Parser

Updates

• 2012-06-?? Add Chris Hodapp version to the post.
• 2012-06-23 Fix word is now in the second sample no method anymore its a val

Create my first parser with the Scala combinator library. I really like the concept to have simple way to compose simple parsers via high-level functions to a complex parser. But I think the syntax for the internal Scala parser DSL is a little bit crazy. I’m not sure why the method names in Scala always must be as short as possible e.g. rep. For me this makes the source of my simple parser really crazy. Here my first simple key value parser to show how the source of Scala parser looks like.


The concept behind the Scala combinator parsers are great, try it and you will learn a lot about how to create a parser in functional language. But I don’t understand why always the shortest and cryptic methods names are used in Scala. This type of naming makes the source hard to read and understand and it makes the Scala source so crazy. But when you know the cryptic names it makes a lot of fun to write such crazy Scala source.

Try it more details about regex parsers please see the Scala doc. The demo parser is not perfect and I’m not a Scala professional, if there are any comments feel free write me how to make it better.

A better Scala version of the parser by Chris Hodapp here: Links

• http://www.scala-lang.org/api/current/index.html#scala.util.parsing.combinator.RegexParsers

Seitenbau Developer Convention 2011 - Getting started with Scala

A week ends now the SDC = Seitenbau Developer Convention is over. Was a cool event again learned a lot about web development html5 with boilerplate, CouchDB, oAuth2, Android development, Gerrit and Skali.

Together with Dennis, I told a bit about the Scala language. Here are the slides of this Scala session

SDC - Einführung in Scala

View more presentations from Christian Baranowski

More about the SDC can be found here (there is also an android app in the android market)
https://www.seitenbau.com/sdc/timetable

Convert a simple CSV File with Groovy, Java, Scala, awk, Ruby, Python, PHP or Bash?

Change Log:

• 05.06.2011 1:30 pm - Initial created Post with  Groovy, Java, Scala, awk, Ruby, Python Implementation
• 05.06.2011 4:00 pm - Add PHP implementation and update voting (now you can vote for PHP).
• 06.06.2011 4:00 pm - Add Bash implementation and update voting (now you can also vote for Bash)

Which is the best programming language for converting a simple CSV into another format?

First I blogged three Java VM based solutions written in Groovy, Java and Scala to convert a simple CSV file into another format. Rainer sends me the Java based solution, yesterday Axel Knauf sends an awk based solution, Niko sends Ruby based solution, Hendrik sends a Python based solution, Sebastian sends me a PHP implementation and Julien sends a Bash version. Now there are a Groovy, Java, Scala, awk, Ruby, Python, PHP and Bash implementation.

Now here again a complete overview of the different implementations:

The Groovy Implementation:

The Java Implementation:

The Scala Implementation:

Here the shell command and awk script:

The pure Ruby Implementation:

The Python Implementation:

The pure PHP Implementation:

The Bash Implementation:


I'm curious whether there are other implementation proposals (Clojure, Perl, PHP, …), if you have one you could send me the script via Twitter or leave a comment here…

I am also curious which implementation Groovy, Java, Scala, awk or Ruby you like and why? I have create voting here:

Thanks Rainer, Axel Knauf, Niko Dittmann, Hendrik Heimbuerger S.Barthenheier and Julien Guitton for the Java, awk, Ruby Python, PHP and Bash implementation.

Links:

• Java (Rainer) - https://gist.github.com/1006757
• awk (Axel Knauf) - https://twitter.com/#!/kopfkind/status/77288701725638656
• Ruby (Niko) - https://gist.github.com/1008877
• Python (Hendrik) - https://gist.github.com/1008881
• PHP (Sebastian) - https://gist.github.com/1008966
• Bash (Julien) - https://gist.github.com/1009420
• old blog post: Convert a CSV File with awk - http://goo.gl/U7onj
• old blog post: Convert a CSV File in Groovy, Java or Scala? - http://goo.gl/AAE17

Convert a CSV File in Groovy, Java or Scala?

Last week I have simple task I must convert a simple CSV file into another CSV format. My first solution was a simple Groovy script. Then inforw sends me a Java solution, to show me that with Java it is no much more code then the Groovy implementation is. Today I wrote just for fun a solution in Scala, to see how the code looks in Scala. My favorite of the three implementations is at the moment the Groovy one. But I think the Scala implementation has the best readability. Below you see the three implementations.

I'm curious what you like, feel free for comments? And I would be glad if someone contributes even further implementation in Clojure, Python, Perl,… or even a better Scala, Java or Groovy implementation.

The Groovy Implementation:

The Java Implementation:

The Scala Implementation:

Thanks @inforw for the discussion and the Java implementation.