Recent codes

[Ruby] Photograhy methods

2008-12-05T11:42:04+00:00

Any comments, corrections, refactorings or suggestions would be fantastic, thanks.
Hopefully we might have some photography nuts out there too :)

# camera related
def frame_diagonal(frame_horizontal, frame_vertical)
	@frame_diagonal = Math.sqrt((frame_horizontal**2) + (frame_vertical**2))
end

def focal_length_multiplier(frame_diagonal_1, frame_diagonal_2)
	@focal_length_multiplier = frame_diagonal_1 / frame_diagonal_2
end

def circle_of_confusion(frame_diagonal)
	@circle_of_confusion = frame_diagonal / 1730
end

# lens related
def hyperfocal_distance(focal_length, f_number, circle_of_confusion)
	@hyperfocal_distance = ((focal_length**2) / (f_number * circle_of_confusion)) + focal_length
end

def near_distance(focus_distance, hyperfocal_distance, focal_length)
	@near_distance = (focus_distance * (hyperfocal_distance - focal_length)) / (hyperfocal_distance + focus_distance - 2 * focal_length)
end

def far_distance(focus_distance, hyperfocal_distance, focal_length)
	@far_distance = (focus_distance * (hyperfocal_distance - focal_length)) / (hyperfocal_distance - focus_distance)
end

def total_distance(near_distance, far_distance)
	@total_distance = far_distance - near_distance
end

def magnification(focal_length, focus_distance)
	@magnification = focal_length/(focus_distance - focal_length)
end

def fov_rectilinear_horizontal(frame_horizontal, focal_length, magnification)
	@fov_rectilinear = 2 * Math.arctan(frame_horizontal/(focal_length * 2 * (magnification+1)))
end

def fov_rectilinear_vertical(frame_vertical, focal_length, magnification)
	@fov_rectilinear = 2 * Math.arctan(frame_vertical/(focal_length * 2 * (magnification+1)))
end

def fov_rectilinear_diagonal(frame_diagonal, focal_length, magnification)
	@fov_rectilinear = 2 * Math.arctan(frame_diagonal/(focal_length * 2 * (magnification+1)))
end

def f_number_to_aperture_diameter(focal_length, f_number)
	@aperture_diameter = focal_length / f_number
end

# exposure related
def exposure_value(f_number, shutter_speed)
	@exposure_value = Math.logn(2, (f_number**2 / shutter_speed))
end

# math related
def Math.logn(x, n)
	Math.log(x) / Math.log(n)
end

def Math.arctan(x)
	Math.atan2(x, 1.0)
end

[Java] Read/download images from an URL

2008-12-05T11:36:17+00:00

Hi guys,
This code downloads some images from the given URL to the hard drive.
In my case I know the URL of the images and the number images of each folder :).

import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;

public class ImagesDownloader {
    public static void main(String[] args) throws IOException {
        getImages("cars", "bikes", "motors");
    }
    
    private static void getImages(String... folders) throws IOException {
        String imagesRootPath = "http://www.mysite.com/images";
        for (String folder : folders) {
            for (int i = 1; i < 31; i++) {
                URL url = new URL(String.format("%s/%s/%d.gif", imagesRootPath, folder, i));
                InputStream in = url.openStream();
                OutputStream out = new BufferedOutputStream(new FileOutputStream(String.format("images/%s/%d.gif", folder, i)));
                for (int b; (b = in.read()) != -1; ) {
                    out.write(b);
                }
                out.close();
                in.close();
                System.out.println(String.format("Image %d.gif from folder %s has been successfully downloaded.", i, folder));
            }
        }
    }
}

[Ruby] Displaying numbers to words.

2008-11-27T13:45:53+00:00

Is it possible to refactore this code in order to display numbers to words from 1 - 1000000 only.

module Verbal
  module English
 
    module Numbers
 
      EXPONENT_EN = {
        0 => '',
        3 => 'thousand',
        6 => 'million',
        9 => 'billion',
        12 => 'trillion',
        15 => 'quadrillion',
        18 => 'quintillion',
        21 => 'sextillion'
      }
 
      NUMBERS_EN = {
        0 => 'zero',
        1 => 'one',
        2 => 'two',
        3 => 'three',
        4 => 'four',
        5 => 'five',
        6 => 'six',
        7 => 'seven',
        8 => 'eight',
        9 => 'nine',
        10 => 'ten',
        20 => 'twenty',
        30 => 'thirty',
        40 => 'fourty',
        50 => 'fifty',
        60 => 'sixty',
        70 => 'seventy',
        80 => 'eighty',
        90 => 'ninety',
        11 => 'eleven',
        12 => 'twelve',
        13 => 'thirteen',
        14 => 'fourteen',
        15 => 'fifteen',
        16 => 'sixteen',
        17 => 'seventeen',
        18 => 'eighteen',
        19 => 'nineteen'
      }
 
      def to_words(value)
        raise 'value must be an integer' unless value.is_a?(Integer)
        @exponent = Verbal::Core::exponent(value)
        @extracted_exponents = Verbal::Core::process_thousands(value)
        @in_words = ''
        @extracted_exponents.each do |e, v|
          @in_words << "#{process_hundreds(v, e, @exponent)} #{EXPONENT_EN[e]} "
        end
        return @in_words.strip.squeeze(' ')
      end
 
      def process_hundreds(value, current_exponent, value_exponent)
      raise 'value should be in range: 0.999' unless (0..999).include?(value)
        if value > 100
 
          hundreds_count = value / 100
          if value % 100 == 0
            return NUMBERS_EN[hundreds_count] + ' hundred'
          else
            prefix = "#{(value_exponent != 0 && current_exponent == 0) ? ' and ': ''}"
            return NUMBERS_EN[hundreds_count] + ' hundred ' + process_tens(value % 100, prefix)
          end
 
        else
          prefix = "#{(value_exponent != 0 && current_exponent == 0) ? ' and ': ''}"
          return process_tens(value % 100, prefix)
        end
      end
 
      def process_tens(value, prefix)
        raise 'value should be in range: 0..99' unless (0..99).include?(value)
        return prefix + NUMBERS_EN[value] if value < 9
        return prefix + NUMBERS_EN[(value / 10) * 10] if (value % 10) == 0
        if (11..19).include?(value)
          return prefix + NUMBERS_EN[value]
        else
          return prefix + NUMBERS_EN[(value / 10) * 10] + '-' + NUMBERS_EN[value % 10]
        end
      end
 
      module_function :to_words, :process_hundreds, :process_tens
 
    end
  end
end

[Python] Williams Words

2008-11-27T04:21:57+00:00

For my blog: http://www.cmurphycode.blogspot.com

A little project via Kottke (http://www.kottke.org/08/11/williams-poems), that I thought would be easy and fun. No need to actually refactor unless you're truly bored- I'm just experimenting with using this as a place to share code.

import sys

#input into this structure
words = {}
#strings generated go here
gen = []
#input word
word = ""
#final output
final = []

#first arg = word to parse, second arg = wordlist name, optional, third arg = (generated word) minimum length, optional
arglength = len(sys.argv)
if arglength > 1:
    word = sys.argv[1]
else:
    print "Please specify an input file"
    quit()
if arglength > 2:
    list = sys.argv[2]
else:
    print "Using default wordlist.txt"
    list = "wordlist.txt"
if arglength > 3:
    cutoff = int(sys.argv[3])
else:
    print "Using default cutoff of 1 letter"
    cutoff = 1

#create output file based on the word we're generating
outFile = "output-" + word + ".txt"
out = open(outFile, 'w')
#create input file 
f = open(list,'r')

#file is one word per line, strip out the endline character, and throw in a dictionary
for line in f:
    line = line.strip()
    if len(line) > cutoff:
        words[line] = 1

#recurse calculates all the substrings forward, is exponential
#input: current string, base string
#example: spray => recurse("s","pray"), recurse("","pray")
def recurse(current, string):
    if string == "":
        return
    gen.append(current)
    gen.append(str(current + string[:1]))
    recurse(current, string[1:])
    recurse(str(current + string[:1]), string[1:])

#check the generated strings for words
#input: string list, word list
def checkOverlap(gen, words):
    for item in gen:
    #these are just strings, so lets check if they're words
        if item in words:
            #ignoring duplicates as we go
            if item not in final:
                final.append(item)
            
           
#start recursion on the input word           
recurse("", word)
#given the generated strings, find the words
checkOverlap(gen, words)
#sort the output
final.sort()
#write the output
for item in final:
    out.write(item)
    out.write('\n')
print "Output written to " + outFile

[Ruby] Doing a 'blank?' in named_scope

2008-11-26T19:01:18+00:00

Can you do a .blank? in a named_scope? (MySQL)

named_scope :with_description, :conditions => "description IS NOT NULL and trim(description) != ''"

[Java] Factoring Integers

2008-11-26T17:30:38+00:00

After taking all the factors of 60 (2, 2, 3, 5), when I invoke hasMoreFactors(), it should return false, cause there are no other factors beyond that 5, yet I can only get it to return true. Any ideas?

/**
   This class generates all the factors of a number.
*/
public class FactorGenerator
{
	private boolean answer;
	private int factor, number;
   /**
      Creates a FactorGenerator object used to determine the factor of
      an input value.
      @param aNum is the input value
   */
   public FactorGenerator(int aNum)
   {
      number = aNum;
      factor = 2;
   }

   /**
      Determine whether or not there are more factors.
      @return true there are more factors
   */
   public boolean hasMoreFactors()
   {
		answer = true;
		while(number % factor != 0 && answer == true)
		{
			if (factor >= number)
			{
				answer = false;
			}
			
		factor++;
		}
		return answer;
   }

   /**
      Calculate the next factor of a value.
      @return factor the next factor
   */
   public int nextFactor()
   {
   	while(factor < number)
   	{
   		if(number%factor == 0)
   		{
   			number/= factor;
   			break;
   		}
   		else
   			factor++;
   	}
   	return factor;
   }
}

[C#] Filterting a List<> with a Regular Expression

2008-11-25T16:33:17+00:00

Have the below code which filters a generic list for certain values. I haven't considered using a predicates to achieve the same effect,

Thanks

  List<Document> documents = documentLayer.GetDocuments(username);
  List<Document> filteredDocuments = new List<Document>();

  string documentName = (string)Session["DocumentName"];
  string documentAuthor = (string)Session["DocumentAuthor"];
            
  if ((string.IsNullOrEmpty(documentName)) && (string.IsNullOrEmpty(documentAuthor)))
  {
    documents.DataSource = documents;
    documents.DataBind();
  }
  else
  {
    foreach (Document document in documents)
    {
      string name = document.Name;
      string author = document.Author;

      if (!(string.IsNullOrEmpty(documentName)) && !(string.IsNullOrEmpty(documentAuthor)))
      {
        if ((Regex.IsMatch(name, documentName)) && (Regex.IsMatch(author, documentAuthor)))
        {
          filteredDocuments.Add(document);
        }
      }
      else if (string.IsNullOrEmpty(documentName))
      {
        if (Regex.IsMatch(author, documentAuthor))
        {
          filteredDocuments.Add(document);
        }
      }
      else if (string.IsNullOrEmpty(documentAuthor))
      {
        if (Regex.IsMatch(name, documentName))
        {
          filteredDocuments.Add(document);
        }
      }
    }
  
    documents.DataSource = filteredDocuments;
    documents.DataBind();
  }

[Ruby] Converting Textile to S5

2008-11-25T14:08:00+00:00

I'd like to take a bunch of textile and turn it into an s5 file.
I was trying to use rubular to isolate blocks of text, but couldn't get just the seperate blocks isolated... Went to looping and ended up with this monstrosity.
There has to be a better way.

example regex trial over at http://www.rubular.com/regexes/4983
closer, but eliminate any more special characters and you get chaos
http://www.rubular.com/regexes/4986

/* sample input
h1. Introduction
* s5 is way cool, but I think in textile
* textile is easy to write
* it would be great to take a bunch of textile and transform it instantly into an s5 presentation

h1. Regular Expressions 
* they are difficult for multiple lines
* http://www.rubular.com/ helps, but I can't narrow it down to the simple bits.
* let's go shopping or use loops

h1. Looping 
* redcloth does the hard work
* you just need to surround the redcloth output with <div class=slide> </div>
* this code smells so bad

h1. You
* please make sense of this

*/

def convert_from_textile_to_s5(fin)
	slide = ""
	File.open(fin) do | file_in|
		lines = file_in.readlines
		i=0
		while i < lines.length
			if lines[i][0..2] == "h1."
				puts '<div class="slide">'
				puts RedCloth.new(lines[i]).to_html
				while i+1 < lines.length && lines[i+1][0,1]=='*'
					slide += lines[i+1]
					i+=1
				end
				puts RedCloth.new(slide).to_html
				slide = ""
				puts '</div>'
			end
			i+=1
		end
	end
end

[Java] Efficiently load a text file into a sorted String Array

2008-11-25T07:04:17+00:00

Has full "finally" blocks, passes findBugs check, should be speedy using TreeSet. Useful for loading data files.

public static String[] loadFile(final String f) {
		String thisLine;
		final SortedSet<String> s = new TreeSet<String>();
		BufferedReader br = null;
		try {
			br = new BufferedReader(new FileReader(f));
			while ((thisLine = br.readLine()) != null)
				s.add(thisLine.trim());
		} catch (IOException ioe) {
			System.err.println("Error reading file " + f);
			throw new RuntimeException(ioe);
		} finally {
			if(br!=null) try {
				br.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return s.toArray(new String[s.size()]);
	}

[Ruby] Cheap ruby block templating

2008-11-22T15:50:01+00:00

Hello all. I've got the following code which I'm using in a Rails helper atm. It seems there a few ways to do this so does anyone know which is the best way?

def field_row(options={}, &block)
  concat("<div class="field_row">", block.binding)
  concat(capture(&block), block.binding)
  concat("</div>", block.binding)
end

# called with something like...

<% field_row do %>
  <%= text_field blah blah blah %>
<% end %>

[Ruby] Bindings on caller

2008-11-22T06:16:53+00:00

I dont really have a need for this but i was trying to figure it out and was curious this sort of thing could be accomplished with bindings.

def test(a, b)
  capitalize_args
  puts a   # => Hello
  puts b   # => World
end

test "hello", "world"

[Ruby] Initial script execution very slow and skewing results

2008-11-22T02:27:39+00:00

Below is a little snippit of a quick response time monitor I was playing around with, works fine BUT when executed the first time everything performs really slowly and skews the duration by 3 to 4 seconds.. after that every execution works as expected.

def monitor(uri)
  Thread.new(uri) do |uri|
    begin
      start = Time.now
      res = open uri
      duration = (Time.now - start).abs
      puts "   %0.3f | %s | %s" % [duration, res.status.join(' '), uri]
    rescue
      puts "   0.000 | 404 Not Found | %s" % [uri]
    end
  end.queue
end

[Ruby] suppress ERB newlines

2008-11-22T02:16:09+00:00

Just plain-jane ERB. What does rails do differently to allow <% -%> and <%= -%> ? to get below to actually format correctly I have to place the erb tags in a gross manor.. initializing ERB with <> or >

  NAME:
  
    <%= @name %>
  
  DESCRIPTION:
  
    <%= @description %>
  
  SYNOPSIS:
  
    <%= @syntax %>

<% unless @examples.empty? %>
  EXAMPLES:
  <% @examples.each do |example| %>  
    # <%= example[:description] %>
    <%= example[:command] %>
  <% end %>
<% end %> 

<% unless @options.empty? %>
  OPTIONS:
  <% @options.each do |option| %>
    <%= option[:args].join(', ') %>
  <% end %>
<% end %>

[Ruby] Arrays, loops, strings...

2008-11-20T22:09:32+00:00

Can this be done in one line?

select = []
joins = []
%w[first second third forth].each{ |semester| joins << ":pdp_#{semester}_semester"; (1..5).each{ |n| select << "pdp_#{semester}_semesters.objetive_#{n} AS #{semester}_objetive_#{n}" }}
[select, joins].each { |x| x.join(', ') }

[Ruby] Similar virtual attributes and their getters/setter

2008-11-20T13:42:18+00:00

My Publication class has a few very similar virtual attributes. Is there any way to unite their setter and getter methods?

class Publication < ActiveRecord::Base

  def publisher_name
    self.publisher.name
  end
  
  def publisher_name=(name)
    self.publisher = Publisher.find_or_create_by_name(name.strip) unless name.blank?
  end
  
  def organization_name
    self.organization.name
  end

  def organization_name=(name)
      self.organization = Organization.find_or_create_by_name(name.strip) unless name.blank?
  end
end

[C#] Check type is XML Serializable

2008-11-19T22:23:15+00:00

I need a fast method to check to see if a type is XML Serializable, be that with the [Serializable] attribute or the IXmlSerializable interface. This is what I came up with. Can we make it better?

/// <summary>
/// Test to see if the type can be XML serialized
/// </summary>
/// <param name="objectToTest"></param>
/// <returns></returns>
private static bool CanBeXmlSerialized(Type objectToTest)
{
	Type[] interfaces = objectToTest.GetInterfaces();
	bool containsIXmlSerializable = interfaces.Contains(typeof(IXmlSerializable));

	return containsIXmlSerializable || objectToTest.IsSerializable;
}

[JavaScript] Serena Collage slideshow

2008-11-19T21:53:29+00:00

Creating a slideshow in our crappy CMS, Collage (from Serena), using a simple doctype called 'slide'.
Early version.

## View [html]
<div id="slideshow" style="background:#FFF">
	<h2 class="slideshowTitle">Around the World with Language</h2>

 <nexus:component classid="nexus/components/AssetQuery" code="/System/Components/nexusComponents.jar" root="$node.path/slides" levelsdeep="0" 
  filter="A.AssetType='slide' AND((A.StartDate is null) OR (A.StartDate <= current timestamp))  AND ((A.ExpireDate >= current timestamp) OR (A.ExpireDate is null))" max="1" orderonmetadata="pageListPriority" orderbycode="1A">
		<div id="slide0" name="slide" style="display:block;">
			<h3 class="slideTitle">$node.contribution("title")</h3>
			<div class="slideImage" width="30%">$node.contribution("image")</div>
			<p class="slideCaption">$node.contribution("caption")</p>
		</div>
  </nexus:component>
  <nexus:component classid="nexus/components/AssetQuery" code="/System/Components/nexusComponents.jar" root="$node.path/slides" levelsdeep="0" 
  filter="A.AssetType='slide' AND((A.StartDate is null) OR (A.StartDate <= current timestamp))  AND ((A.ExpireDate >= current timestamp) OR (A.ExpireDate is null))" skip="1" orderonmetadata="pageListPriority" orderbycode="1A">

		<div id="slide$node.recordnumber" name="slide" style="display:none;">
			<h3 class="slideTitle">$node.contribution("title")</h3>
			<div class="slideImage" width="30%">$node.contribution("image")</div>
			<p class="slideCaption">$node.contribution("caption")</p>
		</div>
  </nexus:component>
	<p id="controls"><a href="javascript:prevslide()">Previous</a> <a href="javascript:nextslide()">Next</a></p>
</div>

## Javascript [javascript]
var slideNum = 0;
var slides = new Array();
slides = document.getElementsByName("slide");

function nextslide() {
	if (slideNum < slides.length - 1) {
		slides[slideNum + 1].style.display = 'block';
		slides[slideNum].style.display = 'none';
		slideNum++;
	}
	else {
		slides[0].style.display = 'block';
		slides[slides.length - 1].style.display = 'none';
		slideNum = 0;
	}
}
function prevslide() {
	if (slideNum > 0) {
		slides[slideNum - 1].style.display = 'block';
		slides[slideNum].style.display = 'none';
		slideNum--;
	}
	else {
		slides[slides.length - 1].style.display = 'block';
		slides[0].style.display = 'none';
		slideNum = slides.length - 1;
	}
}

[Ruby] Shortest regular expression for matching a subdomain.

2008-11-19T18:48:58+00:00

I have written this regular expression which matches any subdomain (consisting of only letters and digits) right below example.com (including the domain, e.g. test.example.com) but not www.example.com. It works, but it is not very elegant.

/(?<part>(w(?!ww)|w(?=www)|w(?=[a-z0-9]+ww)|ww(?=[a-z0-9]+w)|www[a-z0-9]+|[a-vx-z0-9])[a-z0-9]*)\.example\.com/

[Ruby] Caching Methods

2008-11-19T05:23:59+00:00

Is it possible to cache methods in a manor similar to below? (non-RoR). I have a few ideas of how this may work but any suggestions would be great

class Something
  
  def something_else
    "Expensive operation"
  end
  
  cache_method :something_else, :for => 2.hours
  
end

inst = Something.new

# Empty cache
inst.something_else

# Primed cache
inst.something_else

[JavaScript] Tab-Switching in jQuery

2008-11-19T00:45:07+00:00

Is there a better way?

## showcase.html [HTML]
<div id="showcase">
  <ul class="nav">
    <li><a href="#example" class="selected">Example</a></li>
    <li><a href="#another">Another</a></li>
  </ul>
  
  <div class="first item" id="example">
    This is the first item. By default it's shown.
  </div>
  
  <div class="item" id="another">
    This is another item. By default it's hidden.
  </div>
</div>

## showcase.css [css]
#showcase .item {
  display: none;
}

#showcase .first {
  display: block;
}

## showcase.js [javascript]
$(document).ready(function() {
  var selected = $("#showcase .first"); // First is selected by default
  
  $("#showcase .nav a").click( function() {
    if($(this) != selected) {
      $('#showcase .nav a.selected').removeClass('selected');
      selected.hide();
      selected = $($(this).attr('href'));
      selected.show();
      $(this).addClass('selected');
      return false; // Stops link from jumping to the anchor
    }
  })
});

[Perl] Apache log file sorting

2008-11-18T16:22:53+00:00

I have a huge amount of log files on my hard drive and regularly download more. All of the files end up in a single directory. The log file names contain UNIX timestamps. I wrote this script to execute in a given directory and then move the found files to a new path based on the UNIX timestamp. Each new directory is named after a year and the week of the year, e.g. 200801, the first week of 2008. (Actually, the month doesn't have a leading zero yet. I just realized.)

#!/usr/bin/perl -w

use strict;
use Time::localtime;
use File::Find;
use File::Copy;

my $vmlogpath = $ARGV[0] or die "y'all didn't enter no arguments";

find(\&sortFile, $ARGV[0]);

sub sortFile {
    if ( -f ) {
        my $filename=$_;
        $filename =~ /([0-9]{5,})/;
        my $unixtime = $1 or print "Not a log file: $filename\n";
        my $dirname=makeDirName($unixtime);
        unless(-e "${ARGV[0]}/${dirname}/${filename}") {
            my $path=makeDir($ARGV[0], $dirname);
            moveFile($filename, $path);
            print "$filename is the file name.\n";
            print "$unixtime is the extracted unixtime.\n";
            print "$dirname is the directory name.\n";
            print "$path is the path.\n";
        }
    }
    else { print "Not a plain file: $_\n"; }
}

sub moveFile {
    my $tehfile=$_[0];
    my $tehdir=$_[1];

    move($tehfile, $tehdir) or die "Could not move files!\n$!";

    return 1;
}

sub makeDir {
    my $currentdir=$_[0];
    my $newdir=$_[1];
    my $newpath="${currentdir}/${newdir}";
    unless (-d $newpath) {
        mkdir($newpath,755) or die "mkdir failed for $newpath: $!\n"
    }
    return $newpath;
}

sub makeDirName {
    my $tehunix=$_[0];
    my $day_of_year=localtime(int($tehunix))->yday;
    my $week_of_year=int($day_of_year / 7) + 1;
    my $year=1900+localtime(int($tehunix))->year;

    return $year . $week_of_year;
}

[C] How to find max, min of three numbers?

2008-11-18T12:33:54+00:00

I tried to use as less variables and less operators as possible.
Please help to make the code better.

int max = rand(); // or any init value
int min = rand(); // or any init value
int tmp = rand(); // or any init value

if (max < min) {
  if (tmp < min) {
    if (max < tmp) {
      tmp = max;
      max = min;
      min = tmp;
    } 
    else { // max < min && tmp < min && tmp <= max
      max = min;
      min = tmp;
    }
  } 
  else { // max < min && min <= tmp
    min = max;
    max = tmp;
  }
  
}
else { // min <= max
  if (tmp < min)
    min = tmp;

  else // min <= max && min <= tmp
  if (max < tmp)
    max = tmp;
}

[Ruby] repeated code in rspec model test

2008-11-15T08:51:14+00:00

how do i clean up this repeated code (Stock.create & Stock.new) in my rspec test

describe Stock do

  it "should be valid when new" do
    stock = Stock.new(:symbol => 'GOOG')
    stock.should be_valid
  end
  
  it "should be invalid when symbol is empty" do
    stock = Stock.new(:symbol => '')
    stock.should_not be_valid
  end
  
  it "should have symbol in all uppercase" do
    stock = Stock.create(:symbol => 'GOOG')
    stock.symbol.should equal(stock.symbol.upcase)
    
    stock = Stock.create(:symbol => 'goog')
    stock.symbol.should equal(stock.symbol.upcase)
  end

end

[Ruby] A simple factorial program.

2008-11-12T02:16:38+00:00

I'm quite new to Ruby, and I'm currently reading "Why's (Poignant) Guide to Ruby." It's a great book.
Anyway, I want this to do the same thing, WITHOUT recursion, but is there a way to do it without repeating the raise statement at the beginning and using blocks instead of for?

def factorial( n )
  if !(n.is_a? Integer)
    raise ArgumentError, "argument must be a positive integer"
  elsif n < 0
    raise ArgumentError, "argument must be a positive integer"
  end
  factorial = 1
  for i in 1...n
    factorial *= i + 1
  end
  factorial
end

[Haskell] Cat90

2008-11-11T22:53:23+00:00

Rotates text given in stdin 90 degrees.

main = do s <- getContents
          putStr (unlines (reverse (rotate (lines s))))

rotate ls = if (maxLength ls) > 0 then (column ls) : (rotate (dropColumn ls))
                                  else []

maxLength ls = (maximum (map length ls))
column ls = map wholeHead ls
dropColumn ls = map (drop 1) ls

wholeHead cs = if (null cs) then ' '
                            else (head cs)