--- !ruby/object:ExecutablePage
filename: ctfc4kkn385z8hwx57sk3t77qeh497b8ukb
tags:
  :calc:
  :date: 2011-03-26 20:04:26.507557 -07:00
  :log:
  :programming:
  :ruby:
  :spreadsheet:
data:
  :code: |-
    class ::Calculations
      class UnknownReference < NameError ; end
      def self.children ; @children ||= {} ; end
      def self.[] name
        # puts "Fetching #{name} from #{@names.length} names"
        obj = children[name]
        raise UnknownReference, "No such named-object as '#{name.inspect}'" unless obj
        obj
      end
      def self.new name, value
        children.member?(name) ? children[name].value = value : children[name] = super
      end
      def self.wipe
        @children = nil
      end
      attr_reader :dependents, :name, :requirements, :value
      def initialize name, value
        @name = name
        @value = value
        @dependents = []
        @requirements = []
        self
      end
      def invalidate
        # p [:inv, name, @dependents.length]
        @requirements = []
        @result = nil
        @dependents.each {|n| Show(n).invalidate }
        @dependents = [] # They're no-longer dependent on us until they re-reference us
      end
      def value= val
        invalidate unless val == value
        @value = val
      end
      def bind bnd, nm
        # p [:bind, nm, :for, name, :bnd, bnd]
        bnd.eval "#{nm} = Show(:#{nm}).calc"
      end
      def bind_all bnd
        requirements.each {|n| bind bnd, n }
      end
      def add_requirement nm
        # p [:ar, name, nm]
        raise "Re-adding requirement #{nm} to #{name}" if requirements.member? nm
        Show(nm).register_a_dependent name
        requirements << nm
      end
      def register_a_dependent who
        nm = who.respond_to?(:name) ? who.name : who
        dependents << nm unless dependents.member? nm
      end
      def run
        # p [:Cs,self.class.constants - Object.constants]
        bnd = binding
        # p [:bnd, bnd]
        bind_all bnd
        begin
          # puts "Trying lambda"
          v = bnd.eval formula, "solving for #{name}"
          v
        rescue NameError => e
          # puts "Rescued " + e
          if e.class == NameError
            raise "Not the right error '#{e.message}'" unless e.message =~ /^undefined local variable or method `\w+' for /

            nm = e.message.scan(/`(\S+)'/).first.first.to_sym
            add_requirement nm
            bind bnd, nm
            retry
          else
             # puts "Rethrowing #{e.class}"
            raise
          end
        end
      end
      def formula
        return nil unless value.is_a?(String) && value[0..0] == '='
        value[( value[1..-1].index(/[^\s]/) + 1 )..-1]
      end
      def expand_formula recurse = 1, values = false
        # p [:ef1, name, :r, recurse, :v, values]
        # p [:v, value]
        calc rescue puts "Failed to fully graph #{name}" # resolve requirements as far as possible
        f = formula
        # p [:ef,:reql,requirements.length,:req,requirements]
        requirements.each {|n|
          r = Show(n)
          re = /#{n}/
          sf = if r.formula
            # p [:ef,:rf,r.formula]
            "(#{r.expand_formula(recurse - 1, values)})"
          else
            # p [:ef,:rv,r.value]
            "#{r.value.inspect}" if values
          end
          # p [:ef2, name, re, sf]
          f.gsub! re, sf if sf
        } unless recurse.zero?
        f
      end
      def calc
        @result ||= begin
          formula ? run : @value
        end

      end
    end
    def Set *a ; Calculations.new *a ; end
    def Show n ; Calculations[n]     ; end
    def Calc n
      begin
        Show(n).calc
      rescue
        raise unless $!.class <= NameError
        puts $!.message
      end
    end
  :custom_methods:
    :redit:
      :args: "*a"
      :body: |-
        # p [:edit_wrapper, a]
        results = self.class.instance_method(:edit).bind(self).call *a
        Thread.new {
          # sleep 5
          # print "Checking diff"
          unless diff.empty?
            # print " writing"
            write
          end
          # puts " done"
        }
        run
        results
    :run:
      :body: |-
        eval data[:code]
        data[:tax].each {|n,v| Set n, v }
        nil
  :examples: |-
    Calculations.wipe
    Set :wage, 10.25
    Set :hours, 2000
    Set :gross, '= wage * hours'
    Set :tax_rate, 0.35
    Set :tax, '= gross * tax_rate'
    Set :net, '= gross - tax'
    Calc :net
    Set :wage, 10.75 # a raise!
    Calc :net # automatically recalculates
    Show(:net).expand_formula(-1)
  :tax:
  - - :refund
    - "= refund_or_balance_owing < 0 ? refund_or_balance_owing.abs : 0"
  - - :refund_or_balance_owing
    - = total_tax_payable - total_credits
  - - :total_tax_payable
    - = net_federal_tax + bc_tax
  - - :net_federal_tax
    - = federal_tax
  - - :federal_tax
    - = basic_federal_tax
  - - :total_credits
    - = total_income_tax_deducted + bc_credits
  - - :bc_credits
    - 0
  - - :total_income_tax_deducted
    - 4249.82
  - - :basic_federal_tax
    - = s1_39 - s1_44
  - - :s1_39
    - = s1_37
  - - :s1_44
    - = total_federal_nonrefundable_tax_credits
  - - :s1_37
    - = taxable_income * federal_tax_rate
  - - :federal_tax_rate
    - = basic_federal_tax_rate
  - - :basic_federal_tax_rate
    - 0.15
  - - :total_federal_nonrefundable_tax_credits
    - = s1_25 * basic_federal_tax_rate
  - - :s1_25
    - = federal_basic_personal_amount + spouse_amount + cpp_contributions + ei_premiums + employment_amount
  - - :cpp_contributions
    - 1420.57
  - - :ei_premiums
    - 528.53
  - - :federal_basic_personal_amount
    - 10382
  - - :spouse_amount
    - 10382
  - - :employment_amount
    - = [1051, total_employment_income].min
  - - :total_employment_income
    - = employment_income
  - - :employment_income
    - = t4_1_14
  - - :t4_1_14
    - 31571.07
  - - :taxable_income
    - = net_income
  - - :net_income
    - = net_income_before_adjustments
  - - :net_income_before_adjustments
    - = total_income - annual_dues
  - - :annual_dues
    - 528.55
  - - :total_income
    - = employment_income + ei_and_other_benefits
  - - :ei_and_other_benefits
    - 3681.0
  - - :bc_tax
    - = taxable_income * bc_tax_rate - bc_nonrefundable_tax_credits
  - - :bc_tax_rate
    - 0.0506
  - - :bc_nonrefundable_tax_credits_subtotal
    - = bc_basic_personal_amount + bc_spouse_amount + cpp_contributions + ei_premiums
  - - :bc_basic_personal_amount
    - 11000
  - - :bc_spouse_amount
    - = [9653, bc_spouse_amount_subtotal].min
  - - :bc_spouse_amount_subtotal
    - = bc_spouse_basic_amount - spouse_net_income
  - - :bc_spouse_basic_amount
    - 10618
  - - :spouse_net_income
    - 0
  - - :bc_nonrefundable_tax_credits
    - = bc_nonrefundable_tax_credits_subtotal * bc_tax_rate
  - - :unreclaimed_tax
    - = total_income_tax_deducted - refund