From: Robert Klemme <shortcutter@...>
Date: 2009-01-28T15:52:47+09:00
Subject: Re: how can I switch over an array ?

On 28.01.2009 00:31, Tsunami Script wrote:
> I have the following code snippet :
> 
> def call(char,value)
>   case char
>     when " ","#","!","@","$","%","^","&","*","(",")","{","}","
> [","]","\'","\"","<",">",",",".","?",";","\n","\r"
>        @map[char].call(value)
>     when "digit"
>        @map[char].call(value)
>     when "char"
>        @map[char].call(value)
>     else
>        puts "don't know what to do with #{char} and #{value}"
>     end
> end
> 
> can the first when be written in a simpler way ?

PATTERN = [
" ","#","!","@","$","%","^","&","*","(",")","{","}",",",
"digit", "char"
].freeze

def call(char, value)
   if PATTERN.include? char
     @map[char].call(value)
   else
     puts "don't know what to do with #{char} and #{value}"
   end
end

Or, even more efficient

PATTERN2 = Regexp.new("\\A#{Regexp.union(PATTERN)}\\z")

def call(char, value)
   if PATTERN2 =~ char
     @map[char].call(value)
   else
     puts "don't know what to do with #{char} and #{value}"
   end
end

Or, even better (i.e. if @map is filled properly)

def call(char, value)
   c = @map[char]
   if c
     c.call(value)
   else
     puts "don't know what to do with #{char} and #{value}"
   end
end

Cheers

	robert

-- 
remember.guy do |as, often| as.you_can - without end