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Решение на Трета задача от Иван Арабаджиев

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Резултати

  • 6 точки от тестове
  • 0 бонус точки
  • 6 точки общо
  • 12 успешни тест(а)
  • 1 неуспешни тест(а)

Код

class Expr
attr_reader :spaghetti
def initialize(spaghetti)
@spaghetti = spaghetti
end
def self.build(spaghetti)
Expr.new spaghetti
end
def evaluate(environment = {})
Expr.handler(@spaghetti.first).evaluate spaghetti, environment
end
def simplify
Expr.handler(@spaghetti.first).simplify @spaghetti
end
def self.base_derive(expr)
Expr.handler(expr.first).base_derive
end
def self.handler(wish)
case wish
when :number then Number
when :variable then Variable
when :+ then Addition
when :- then Negation
when :* then Multiplication
when :sin then Sine
when :cos then Cosine
end
end
def ==(other)
@spaghetti == other.spaghetti
end
end
module Number
ZERO = [:number, 0].freeze
ONE = [:number, 1].freeze
def self.evaluate(expr, environment = {})
expr.last
end
def self.simplify(expr)
Expr.build expr
end
def self.to_expr(number)
Expr.build [:number, number]
end
end
module Variable
def self.evaluate(expr, environment = {})
raise 'Cannot calculate that!' unless environment.include? expr.last
environment[expr.last]
end
def self.simplify(expr)
Expr.build expr
end
end
module Addition
def self.evaluate(expr, environment = {})
Expr.build(expr[1]).evaluate(environment) + Expr.build(expr[2]).evaluate(environment)
end
def self.simplify(expr)
if expr.include? Number::ZERO
simple = expr[3 - expr.index(Number::ZERO)]
Expr.build(simple).simplify
else
Expr.build(Number.to_expr Expr.build(expr).evaluate)
end
rescue
Expr.build expr
end
end
module Negation
def self.evaluate(expr, environment = {})
-Expr.build(expr.last).evaluate(environment)
end
def self.simplify(expr)
Expr.build expr
end
end
module Multiplication
def self.evaluate(expr, environment = {})
return 0 if expr.include? Number::ZERO
Expr.build(expr[1]).evaluate(environment) * Expr.build(expr[2]).evaluate(environment)
end
def self.simplify(expr)
if expr.include? Number::ONE
simple = expr[3 - expr.index(Number::ONE)]
Number.to_expr Expr.build(simple).evaluate rescue Expr.build simple
else
Number.to_expr Expr.build(expr).evaluate rescue Expr.build expr
end
end
end
module Sine
def self.evaluate(expr, environment = {})
Math.sin Expr.build(expr[1]).evaluate(environment)
end
def self.simplify(expr)
return Number::ZERO if Expr.build(expr).evaluate.zero?
Expr.build expr
rescue
Expr.build expr
end
end
module Cosine
def self.evaluate(expr, environment = {})
Math.cos Expr.build(expr[1]).evaluate(environment)
end
def self.simplify(expr)
return Expr.build Number::ONE if Expr.build(expr).evaluate.zero?
Expr.build expr
rescue
Expr.build expr
end
end

Лог от изпълнението

...F.........

Failures:

  1) Expressions assignment can derive expressions
     Failure/Error: build(string).derive(:x)
     NoMethodError:
       undefined method `derive' for #<Expr:0xa64db9c @spaghetti=[:variable, :x]>
     # /tmp/d20130203-23049-18rvzsz/spec.rb:129:in `derive'
     # /tmp/d20130203-23049-18rvzsz/spec.rb:161:in `block (3 levels) in <top (required)>'
     # ./lib/homework/run_with_timeout.rb:5:in `block (3 levels) in <top (required)>'
     # ./lib/homework/run_with_timeout.rb:5:in `block (2 levels) in <top (required)>'

Finished in 0.04619 seconds
13 examples, 1 failure

Failed examples:

rspec /tmp/d20130203-23049-18rvzsz/spec.rb:160 # Expressions assignment can derive expressions

История (1 версия и 0 коментара)

Иван обнови решението на 14.11.2012 01:43 (преди около 12 години)

+class Expr
+ attr_reader :spaghetti
+ def initialize(spaghetti)
+ @spaghetti = spaghetti
+ end
+
+ def self.build(spaghetti)
+ Expr.new spaghetti
+ end
+
+ def evaluate(environment = {})
+ Expr.handler(@spaghetti.first).evaluate spaghetti, environment
+ end
+
+ def simplify
+ Expr.handler(@spaghetti.first).simplify @spaghetti
+ end
+
+ def self.base_derive(expr)
+ Expr.handler(expr.first).base_derive
+ end
+
+ def self.handler(wish)
+ case wish
+ when :number then Number
+ when :variable then Variable
+ when :+ then Addition
+ when :- then Negation
+ when :* then Multiplication
+ when :sin then Sine
+ when :cos then Cosine
+ end
+ end
+
+ def ==(other)
+ @spaghetti == other.spaghetti
+ end
+end
+
+module Number
+ ZERO = [:number, 0].freeze
+ ONE = [:number, 1].freeze
+
+ def self.evaluate(expr, environment = {})
+ expr.last
+ end
+
+ def self.simplify(expr)
+ Expr.build expr
+ end
+
+ def self.to_expr(number)
+ Expr.build [:number, number]
+ end
+end
+
+module Variable
+ def self.evaluate(expr, environment = {})
+ raise 'Cannot calculate that!' unless environment.include? expr.last
+ environment[expr.last]
+ end
+
+ def self.simplify(expr)
+ Expr.build expr
+ end
+end
+
+module Addition
+ def self.evaluate(expr, environment = {})
+ Expr.build(expr[1]).evaluate(environment) + Expr.build(expr[2]).evaluate(environment)
+ end
+
+ def self.simplify(expr)
+ if expr.include? Number::ZERO
+ simple = expr[3 - expr.index(Number::ZERO)]
+ Expr.build(simple).simplify
+ else
+ Expr.build(Number.to_expr Expr.build(expr).evaluate)
+ end
+ rescue
+ Expr.build expr
+ end
+end
+
+module Negation
+ def self.evaluate(expr, environment = {})
+ -Expr.build(expr.last).evaluate(environment)
+ end
+
+ def self.simplify(expr)
+ Expr.build expr
+ end
+end
+
+module Multiplication
+ def self.evaluate(expr, environment = {})
+ return 0 if expr.include? Number::ZERO
+ Expr.build(expr[1]).evaluate(environment) * Expr.build(expr[2]).evaluate(environment)
+ end
+
+ def self.simplify(expr)
+ if expr.include? Number::ONE
+ simple = expr[3 - expr.index(Number::ONE)]
+ Number.to_expr Expr.build(simple).evaluate rescue Expr.build simple
+ else
+ Number.to_expr Expr.build(expr).evaluate rescue Expr.build expr
+ end
+ end
+end
+
+module Sine
+ def self.evaluate(expr, environment = {})
+ Math.sin Expr.build(expr[1]).evaluate(environment)
+ end
+
+ def self.simplify(expr)
+ return Number::ZERO if Expr.build(expr).evaluate.zero?
+ Expr.build expr
+ rescue
+ Expr.build expr
+ end
+end
+
+module Cosine
+ def self.evaluate(expr, environment = {})
+ Math.cos Expr.build(expr[1]).evaluate(environment)
+ end
+
+ def self.simplify(expr)
+ return Expr.build Number::ONE if Expr.build(expr).evaluate.zero?
+ Expr.build expr
+ rescue
+ Expr.build expr
+ end
+end