1. Scala
id:clairvy
2010/09/04
@Scala 01

2. Scala
id:clairvy
2010/09/04
@Scala 01

3. • id:clairvy (
•4 PHPer
• Perl

5. •

6. Church
0 := λf x. x
• 1 := λf x. f x
• :

7. object Main {
override def main(args : Array[String]) {
println("zero: " + zero(0)(i => i +1))
println("one: " + succ[Int](zero)(0)(i => i + 1))
def zero[A](i : A) = (f : A => A) => i
def succ[A](n : A=>(A=>A)=>A) = (i:A)=>(f:A=>A)=>f(n(i)(f))
}
}

8. • [Int]

9. • [Int]
•

10. • [Int]
•
•

11. Android Recipes
with Scala

12. Android Recipes
with Scala
• 108104 1 …

13. Android Recipes
with Scala
• 108104 1 …
• id:papamitra …

14. Android Recipes
with Scala
• 108104 1 …
• id:papamitra …
• @gabu …

15. Android Recipes
with Scala
• 108104 1 …
• id:papamitra …
• @gabu …
• Recipe001 YO

16. orz

17. orz
• OCamlMeetingNagoya

18. orz
• OCamlMeetingNagoya
• OCamlGolf sort

19. orz
• OCamlMeetingNagoya
• OCamlGolf sort
•

21. •

22. •
•

23. •
•
•

24. • scala + zsh

25. export JAVACMD=$HOME/local/bin/java
function scall () {
local f
while getopts 'e:B:E:' opt; do
case $opt in
B) B=$OPTARG;;
E) E=$OPTARG;;
e) f=$OPTARG;;
esac
done
shift $((OPTIND - 1))
if [[ x"$f" == x"" ]]; then
f='println'
fi
scala -e "import scala.io._;$B;
(if(args.length>0)args.map(arg=>Source.fromFile(arg,
"UTF-8"))else
Array(Source.stdin)).foreach(s=>s.getLines.foreach($f));$E" "$@"
}

26. #compdef scall
function _scall () {
_arguments :
'-h[Show message and exit]'
'-e[Specify expression to run with each line]:Expression'
'-B[Specify expression to run on begin of
program]:Expression'
'-E[Specify expression to run on end of program]:Expression'
'*:argument:_files'
}

27. • Zsh
•

28. • …

29. $ time (scall ~/.zshrc > /dev/null)
(; scall ~/.zshrc > /dev/null; )
1.76s user 0.17s system 42% cpu 4.536 total
$ time (cat ~/.zshrc > /dev/null)
(; cat ~/.zshrc > /dev/null; )
0.00s user 0.00s system 61% cpu 0.004 total
$ time (perl -pe1 ~/.zshrc > /dev/null)
(; perl -pe1 ~/.zshrc > /dev/null; )
0.00s user 0.00s system 52% cpu 0.008 total

31. •

32. object Scall {
import scala.tools.nsc._
import scala.io._
def main(args : Array[String]) {
//
val interp : Interpreter = new Interpreter()
val script = "((" + begin + "), (" + expression + "), (" +
end + "))"
var result : (()=>Unit, (String)=>Unit, ()=>Unit) = null
interp.eval[(()=>Unit, (String)=>Unit, ()=> Unit)](script)
match {
case Some(ret) => result = ret;
case _ => println("compile error");exit(1);
}
result._1()
(if (files.length > 0) files.map(f=>Source.fromFile(f)) else
List(Source.stdin)).foreach(f=>f.getLines.foreach((l:String)=>re
sult._2(l)))
result._3()
}
}

33. …
• …
•

34. #
$ time (scall ~/.zshrc > /dev/null)
(; scala-2.8 -deprecation -cp com.myexample.Scall ~/.zshrc > /
dev/null; )
13.35s user 0.75s system 72% cpu 19.502 total
$ time (cat ~/.zshrc > /dev/null)
(; cat ~/.zshrc > /dev/null; )
0.00s user 0.00s system 61% cpu 0.004 total
$ time (perl -pe1 ~/.zshrc > /dev/null)
(; perl -pe1 ~/.zshrc > /dev/null; )
0.00s user 0.00s system 52% cpu 0.008 total

35. •
(by )