Update session4 solutions

session4/solved/1.rb

@@ -4,7 +4,7 @@
 
 class Stack
   def inspect
-    current = @head
+    current   = @head
     to_return = "("
     while current
       to_return << current.data.inspect

session4/solved/3.rb

@@ -1,6 +1,6 @@
-def passthrough( enumerable , to_pass )
-  enumerable.each do |element| 
-    to_pass = yield to_pass , element
+def passthrough(enumerable, to_pass, &block)
+  enumerable.each do |element|
+    to_pass = block.call(to_pass, element)
   end
   to_pass
-end
+end

session4/solved/5.rb

@@ -1,21 +1,6 @@
-# you will be given a filen name
-# inside the file will be a series of numbers
-# find the largest number on each line
-# return their sum
-#
-# EXAMPLE
-#     file: nums.txt
-#      406 217 799 116 45 651 808 780 
-#      205 919 474 567 712 
-#      776 170 681 86 822 9 100 540 812 
-#      602 117 181 169 876 336 
-#      434 165 725 187 974 48
-#
-# line_sums('nums.txt')   # =>   808 + 919 + 822 + 876 + 974   # =>   4399
-
 def line_sums(filename)
-  File.readlines(filename).inject 0 do |sum,line|
+  File.readlines(filename).inject 0 do |sum, line|
     numbers = line.split.map { |number| number.to_i }
     sum + numbers.max
   end
-end
+end

session4/solved/6.rb

@@ -1,20 +1,11 @@
-class ApplicationController  
-
-
+class ApplicationController
   def body_class
-
-    unless @body_class
-      @body_class = String.new
-      class << @body_class
-        def <<(str)
-          concat ' ' unless length.zero?
-          concat str
-        end
-      end
+    return @body_class if @body_class
+    @body_class = String.new
+    def @body_class.<<(str)
+      concat ' ' unless length.zero?
+      concat str
     end
-
     @body_class
   end
-
-
 end

session4/solved/8.rb

@@ -2,15 +2,10 @@ class RubyKickstartException < Exception
 end
 
 def exception_raiser(num)
-  if num == 1
-    raise "No 1s allowed!"
-  elsif num == 2
-    raise ArgumentError.new("No 2s allowed!")
-  elsif num == 3
-    raise Exception.new("No 3s allowed!")
-  elsif num == 4
-    raise SyntaxError.new("No 4s allowed!")
-  elsif num == 5
-    raise RubyKickstartException.new("No 5s allowed!")
+  if    num == 1 then raise                         "No 1s allowed!"
+  elsif num == 2 then raise ArgumentError,          "No 2s allowed!"
+  elsif num == 3 then raise Exception,              "No 3s allowed!"
+  elsif num == 4 then raise SyntaxError,            "No 4s allowed!"
+  elsif num == 5 then raise RubyKickstartException, "No 5s allowed!"
   end
 end