mutually_exclusive_collection.rb in rodders-3.1.0

- old
+ new

@@ -2,11 +2,11 @@
 # Includes methods for sports betting arbitrage. Due to the discrete nature
 # of real-world monetary amounts, there may be small rounding errors.
 class MutuallyExclusiveCollection
   # create a new collection with the given odds
   # @param [Array<FixedOdds>] mutually_exclusive_outcome_odds the odds for all the mutually exclusive outcomes
-  def initialize(mutually_exclusive_outcome_odds)
+  def initialize mutually_exclusive_outcome_odds
     @mutually_exclusive_outcome_odds = mutually_exclusive_outcome_odds.sort
   end
 
   # the least likely of the odds to occur
   # @return [FixedOdds] the least likely odd
@@ -41,35 +41,31 @@
 
   # the bookmaker's return rate
   # @return [Number] the bookmaker's return rate as a percentage
   def bookmakers_return_rate
     fs = fractions
-    fs.any? ? 1 - fs.reduce(:*) / fs.reduce(:+) : 0
+    1 - fs.reduce(:*) / fs.reduce(:+) if fs.any?
   end
 
   # hash of the odds and what percentage of the total stake should go on each
   # @return [Hash<FixedOdds, Number>] hash of odds to percentages
   def percentages
-    hash = {}
-    @mutually_exclusive_outcome_odds.each {|odds| hash[odds] = 1 / odds.fractional_odds / sum_inverse_outcome }
-    hash
+    @mutually_exclusive_outcome_odds.each_with_object({}) {|odds, hash| hash[odds] = 1 / odds.fractional_odds / sum_inverse_outcome }
   end
 
   # hash of the odds and what stakes to put on each given a total stake
   # @param [Money] total_stake the money to distribute on the outcomes
   # @return [Hash<FixedOdds, Money>] hash of odds to stakes
   def stakes_for_total_stake total_stake
-    hash = {}
-    @mutually_exclusive_outcome_odds.each {|odds| hash[odds] = total_stake / odds.fractional_odds / sum_inverse_outcome }
-    hash
+    @mutually_exclusive_outcome_odds.each_with_object({}) {|odds, hash| hash[odds] = total_stake / odds.fractional_odds / sum_inverse_outcome }
   end
 
   # hash of the odds and the stakes needed to make the specified profit
   # @param (see #stakes_for_total_stake)
   # @return (see #stakes_for_total_stake)
   def stakes_for_profit desired_profit
-    stakes_for_total_stake(stake_to_profit(desired_profit))
+    stakes_for_total_stake stake_to_profit desired_profit
   end
 
   # the stake needed to win the desired profit
   # @param [Money] desired_profit the profit to gain from arbitrage
   # @return [Money] the stake necessary to realise the desired profit
@@ -95,8 +91,8 @@
     def sum_inverse_outcome
       fractions.reduce(0) {|sum, n| sum + Rational(1, n) }
     end
 
     def fractions
-      @mutually_exclusive_outcome_odds.collect {|o| o.fractional_odds }
+      @mutually_exclusive_outcome_odds.collect &:fractional_odds
     end
 end
\ No newline at end of file