From: Mikael Brockman <phubuh@...>
Date: 2004-06-27T09:30:54+09:00
Subject: Re: Writing UNIX 'wc' program

"@*(&SPAM&)*optonline.net" <" kboruff\""@*.*optonline.net> (&SPAM&)> writes:

> Hey all,
> 
> I've been spending the last week learning Ruby. Prior to that, I had
> spent some time learning Python. For various reasons, it looks like
> I'm gravitating more to Ruby.
> 
> That being said, I decided to write a small program similiar to the
> UNIX 'wc' program.
> 
> Right now, it's very stripped down being that it only accepts input
> data from STDIN if not a tty and I also haven't yet implemented the
> command line arguments.
> 
> For the context of this post, I only included the logic that
> gets/prints the word count and gets/prints the length of the longest
> line since these are the ones I have questions about. Here it is:
>
> [...]
> 
> # I'm wondering if there's an easier way to do this. It would
> # be nice of the String::count method accepted regex patterns
> # and not just strings.
> 
> # As it stands, this method creates a seperate array of words
> # for which I get the count of. I would've rather done this
> # without the extra overhead but I guess it's no big deal: it works!
> printf("Word Count: %d\n", data.split(/\s/).length)

How about something like this?

| class String
|   def match_count (pattern)
|     count = 0
|     scan (pattern) { count = count + 1 }
|     return count
|   end
| 
|   def word_count
|     match_count /\w+/
|   end
| end
| 
| puts "Word Count: #{data.word_count}"

Or put the methods outside of String if you prefer.

> 
> # GET THE LENGTH OF THE LONGEST LINE
> 
> # If there's a more elegant solution than what I have below, I'm all
> # ears
> line_length = 0
> data.split(/\n/).each do |line|
>     line_length = line.length if line_length < line.length
> end

I'd write something like

| maximum_length = 0
| data.each_line do |line|
|   if line.length > maximum_length then
|     maximum_length = line.length
|   end
| end

which doesn't need to keep all lines in an array.


  mikael