From: globalrev <skanemupp@...>
Date: 2008-05-09T10:15:05+09:00
Subject: Re: Check if char in string?

On 8 Maj, 21:26, Adam Shelly <adam.she...@gmail.com> wrote:
> On 5/8/08, globalrev <skanem...@yahoo.se> wrote:> On 8 Maj, 15:12, Heesob Park <pha...@gmail.com> wrote:
> > > globalrev wrote:
> > > > i then changed to !~ just like haesob said but if i do /aeiouy / it
> > > > doesnt react to space " ". how do i get it to treat " " as "a"?
>
> It's all in the book...
>
> From "Programming Ruby", in Standard Types/ Regular Expressions
> /Character Classes:
> " A character class is a set of characters between brackets: ...
> [aeiou] will match a vowel ... addition, you can use the abbreviations
> ..  so that (for example) \s matches any whitespace character"
> and a bit further down:
> "Put a ^ immediately after the opening bracket to negate a character
> class: [^a-z] matches any character that isn't a lowercase alphabetic"
>
> That should give you all the information to build the expression you need:
> c !~ [\saeiouy]
> c
> !~        #does not match
> /[        #any
> \s        #whitespace
> aeiouy]   #or vowel ...
>
> which is exactly what Park Heesob said:
>
> > > You can do with like this:
> > > if str[x].chr !~ /[\saeiouy]/
>
> An equivalent version moves the 'not' inside the character class:
> if str[x].chr =~ /[^\saeiouy]/
>
>
>
> > > BTW, your encryption equals to
> > > str.gsub(/([^\saeiouy])/,"\\1o\\1")
>
> > that doesnt seem to work, it repeats the sma ething alot of times
> > befre next letter.
>
> > if this is what u meant (why did u add the "s" ?):
>
> > for x in (0..str.length()-1)
> >   str = str.gsub(/([^\aeiouy])/,"\\1o\\1")
> > end
> > print str
>
> That's not what he meant, check the docs for gsub:
> "Returns a copy of str with *all* occurrences of pattern replaced with
> either replacement or the value of the block".   So essentially,  gsub
> does the loop over all the characters for you.   Your whole encode
> function can be as simple as:
>
> def encode str; str.gsub(/([^\saeiouy])/,"\\1o\\1"); end
>
> I'd modify it to deal with case:
> str.gsub(/([^\saeiouy])/i){|c|"#{c}o#{c.downcase}"}
>
> will encode "Hi Oliver" into
> "Hohi Ololivoveror", instead of
> "HoHi OoOlolivoveror"
>
> HTH,
> -Adam

is there some equally clever way to replace decode?

puts "Enter code to decrypt: "
code = gets
x = 0
dec = ""
while (x<code.length())
        dec = dec + code[x].chr
        if code[x].chr !~ /[\saeiouy]/
                x = x + 2
        end
        x = x + 1
end
print dec