7L7W

ruby-day2-grep.rb

filename = 'text.txt'
pattern = ARGV[0]
pattern = "" if pattern == nil

File.open(filename, 'r') do |f| 
	lines = f.readlines
	lines.each {|line| puts line if line =~ Regexp.new(pattern)}
end

ruby-day2-tree.rb

class Tree

	attr_accessor :children, :node_name

	def initialize(structure = {})
		@children = []
		
		subtree = structure.shift		
		@node_name = subtree[0]

		subtree[1].each {|key, value| @children.push(Tree.new({key => value}))}
	end

	def visit_all(&block)
		visit &block
		children.each {|c| c.visit_all &block}
	end

	def visit(&block)
		block.call self
	end

end

ruby_tree = Tree.new( {'grandpa' => {'dad' => {'child 1' => {}, 'child 2' => {}}, 'uncle' => {'child 3' => {}, 'child 4' => {}}}} )

puts "Visiting a node"
ruby_tree.visit {|node| puts node.node_name}
puts

puts "visiting entire tree"
ruby_tree.visit_all {|node| puts node.node_name}

ruby-day3-csv.rb

module ActsAsCsv

	def self.included(base)
		base.extend ClassMethods
	end

	module ClassMethods
		def acts_as_csv
			include InstanceMethods
		end
	end

	module InstanceMethods

		class CsvRow
			attr_accessor :columns

			def method_missing name, *args
				@columns[name.to_s]
			end

			def initialize
				@columns = {}
			end
		end

		def read
			@csv_contents = []
			filename = self.class.to_s.downcase + '.txt'
			file = File.new(filename)
			@headers = file.gets.chomp.split(', ')

			file.each do |row|
				@csv_contents << row.chomp.split(', ')
			end
		end

		def each
			@csv_contents.each do |row| 
				csv_row = CsvRow.new
				row.each_index {|column_idx| csv_row.columns[@headers[column_idx]] = row[column_idx]}
				
				yield csv_row
			end
		end

		attr_accessor :headers, :csv_contents

		def initialize
			read
		end

	end

end

class RubyCsv
	include ActsAsCsv
	acts_as_csv
end

csv = RubyCsv.new
csv.each {|row| puts row.brand}

ruby.d2.e1.rb

a = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]

(0..3).each {|iteration| p a[(iteration*4)..(iteration*4 + 3)]}

a.each_slice(4) {|content| p content}