hungryblank

[Ruby] On Rubyize this : 3rd edition

2007-10-12T13:39:10-07:00

This solution uses a different regexp

/#{%w( stupid moron dumbass retard ).join('|')}/i

generates this regexp

/stupid|moron|dumbass|retard/i

that can be used to match any insult in the given sentence

def remove_insults(sentence)
  sentence.gsub(/#{%w( stupid moron dumbass retard ).join('|')}/i) { |insult| '*' * insult.size }
end

puts remove_insults("you truly are a 'Stupid' moron, stupid sir!")

[Ruby] On Random number generator

2007-10-03T03:34:27-07:00

and in case you really want just numbers...

500.times { puts((1..16).map { rand(10) }.to_s) }

[Ruby] On Random number generator

2007-10-03T03:25:20-07:00

stressing a bit the [] method...

500.times { puts((1..16).inject('') { |a,n| a << '1234567890'[rand(10),1] }) }

# or

500.times { puts((1..16).map { '1234567890'[rand(10),1] }.join) }

[Ruby] On Show a default value if object or field is empty?

2007-10-03T02:50:12-07:00

As a first step you can avoid using the block in the method.
The following doesn't need a block.
Note that in your code if the object is not nil and the method doesn't return blank the method is called twice on the object.

Below there's a code that doesn't use blocks and calls the method only once.

A better solution would be to have your 'object' to return the default value for the method instead of the blank.
Other than that the default values should be constants defined in your classes so they'll be easy to change when needed.

# samples
# show_value_or_default(user, :phone)
# show_value_or_default(user2, :phone, "leeg")

def show_value_or_default(object, method, default = "-")
  return value if object.respond_to?(method) && !(value = object.send(method)).blank?
  default
end

[Ruby] On Grouping an array of hashes

2007-10-01T15:40:24-07:00

I thought for you it was important array_of_arrays_of_hashes[idx] would return the array with the idx caller id.
But is not because after you apply the compact method and this breaks the relationship between array_of_arrays_of_hashes index and callid.
In this case the code below should be enough.

array_of_arrays_of_hashes = array_of_hashes.map { |e| e[:callid] }.uniq.inject([]) do |grouped_array, callid|
  grouped_array << array_of_hashes.select { |h| h[:callid] == callid }
end

[Ruby] On compound interest

2007-10-01T09:38:19-07:00

This is just an example on how you can wrap the calculation in a class.
one method provide the calculation of the value at any time in the future.

class Investment < Struct.new(:start_year, :start_value, :interest_rate)

  def value_at(year)
    start_value * (1 + interest_rate) ** (year - start_year)
  end

end

# # Sample usage
# we invest 100 in 1990 at 5% interest and want to know the value per
# every year from 1990 to 2005

i = Investment.new(1990, 100, 0.05)
(1990..2005).each { |year| puts i.value_at(year) }

[Ruby] On Extracting style from a CSS file

2007-09-28T04:39:41-07:00

I just played some mins around the regexp with no luck
so I came out with this

CssObj.extract_file(filename)

will return an array of objects, each object respond to 'selector' and 'attributes' methods.
Some major cleaning is required

CssObj = Struct.new(:selector, :attributes)
class CssObj
  def self.extract_file(filename)
    css = File.read(filename)
    tokens = css.split(/\}/m)
    tokens.map { |token| CssObj.new(*token.split(/\{/m)) }
  end
end