tree implement in ruby

Just for fun, but it work well.

 01 #!/usr/bin/env ruby
 02 # 
 03 # 
 04 
 05 
 06 def tree(dirname, indent = "  |")
 07     puts dirname + "/" if indent == "  |"
 08     dir = Dir.open dirname
 09     for f in dir
 10         if f == "." || f == ".."
 11             next
 12         elsif File.directory? dirname+"/"+f
 13             puts indent + "-" + f + "/"
 14             tree( dirname+"/"+f, indent+"  |")
 15         else
 16             puts indent + "-" + f
 17         end
 18     end
 19 end
 20 
 21 tree (ARGV[0]? ARGV[0] : ".")

 

closure tip

closure is so fun.
well design for meta programming.

note 1:

 01 #!/usr/bin/env ruby        
 02
 03 class Hash
 04     def find_all
 05         temp_hash = {}
 06         each {|key,value| temp_hash[key] = value if yield(key,value) }
 07         temp_hash
 08     end 
 09 end 
 10 
 11 square = { 0 => 0, 1 => 1, 2 => 4, 3 => 9 }
 12 
 13 new = square.find_all { |key,value| key > 1 }
 14 puts new.inspect

pass yield values.

note 2:

 01 #!/usr/bin/env ruby        
 02
 03 class Person
 04     attr_accessor :name
 05     def initialize(name)
 06         @name = name       
 07     end
 08 end
 09 
 10 def command(obj,method)    
 11     obj.each {|x| yield x.send(method)}
 12 end
 13 
 14 family = []
 15 
 16 %w(shelling sherry appollo).each do |name|
 17     family.push Person.new(name)    
 18 end
 19 
 20 command family, :name do |x|
 21     puts "hello, I am #{x}."
 22 end

Every object in array call the same function.

 
 

Mac OS X Terminal tip

leopard terminal use xterm-color as default, but conflict with linux when ssh. The backspace act as delete(kill word at right not left). Mac OS hint provide a good solution, Copy /usr/share/terminfo/78/xterm-color on mac to ~/.terminfo/x/ on linux box. Not affect linux default setting. It saves my emacs in screen environment :D

 
 

sample scheme

hello, world! here
#!/usr/bin/guile -s
!#
(write "hello, world!")

define function
(define square (lambda (n) (* n n) ) )
(write (square 3) ) ; output 9

link1: The Scheme Programming Language 3/e
link2: Scheme Tutorial
 
 

shelling.idv.tw

買了 shelling.idv.tw，不過什麼都還沒配置 :D

self.pm

some convenient usage I prefer. :p

package PackageName;
use self;
use strict;

my @args;

sub new {
    @args = args;
    for (@args) {
        blah~!
    }
    bless {}, self;
}

1;

self.pm++
 
 

some vim

something is fun from learning the vi editor 6/e:

    dwelp change two words
    xp change two alphabets

內灣出遊微記

昨日帶友人繞過大半個新竹，一直以來都不喜新竹風物，常感食衣住行皆不盡人意，即便與大學同學出遊也甚感無聊，但昨日與友人暢遊內灣，吃盡美食，甚感愉快。看來在一個地方生活是否能讓人滿意，最重要的仍然是人。