Class: Variable

Inherits:
Object
  • Object
show all
Defined in:
lib/chebyruby/variable.rb

Overview

This is the class for a variable in an expression. It is part of the CAS side-project in ChebyRuby.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(x, neg = false) ⇒ Variable

This is the constructor for the variable class

Parameters:

  • x (String) —

    the variable name to initialize

  • neg (Boolean) (defaults to: false) —

    the negation status of the variable



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# File 'lib/chebyruby/variable.rb', line 15

def initialize(x, neg = false)
  @x = x
  @neg = false
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *args) ⇒ Object

This variadic method missing works with Expression’s method missing to construct and expression from variables.

Parameters:

  • method (Object) —

    the method that is missing

  • args (Object[]) —

    the args that are passed to the missing method

Returns:

  • a new expression



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# File 'lib/chebyruby/variable.rb', line 26

def method_missing(method, *args)
  Expression.new(self, method, Variable.new(args[0]))
end

Instance Attribute Details

#neg ⇒ Boolean

the negation status of the variable

Returns:

  • (Boolean) —

    the current value of neg



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# File 'lib/chebyruby/variable.rb', line 8

def neg
  @neg
end

#x ⇒ String

the variable name

Returns:

  • (String) —

    the current value of x



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# File 'lib/chebyruby/variable.rb', line 8

def x
  @x
end

Instance Method Details

#-@ ⇒ Object

This is an overriding of the unary negation operation that allows for negation of a variable as simply as -x.

Returns:

  • a negated form of the current variable



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# File 'lib/chebyruby/variable.rb', line 45

def -@
  Variable.new(@x, !@neg)
end

#parseable ⇒ Object

Returns a parseable version of the variable/expression for computer system modification.

Returns:

  • parseable form



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# File 'lib/chebyruby/variable.rb', line 74

def parseable
  to_enum.map do |i|
    if Array === i
      i.parseable
    elsif Symbol === i
      i
    else
      i.x
    end
  end
end

#right ⇒ Object

A nil returning function for the purposes of expression building

Returns:

  • nil



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# File 'lib/chebyruby/variable.rb', line 59

def right
  nil
end

#to_a ⇒ Object Also known as: to_ary

This method will turn a variadic variable into an array

Returns:

  • an array of the variable



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# File 'lib/chebyruby/variable.rb', line 33

def to_a
  if x.class == Array
    x
  else
    [x]
  end
end

#to_enum ⇒ Object

This turns the current array variable into an enumerator

Returns:

  • an enumerated form of the array variable



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# File 'lib/chebyruby/variable.rb', line 52

def to_enum
  Array.new(to_ary).to_enum
end

#to_s ⇒ Object

A basic to_s function

Returns:

  • a string



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# File 'lib/chebyruby/variable.rb', line 66

def to_s
  "#{x}"
end