Class: Keisan::AST::ListAssignment

Inherits:
Object
  • Object
show all
Defined in:
lib/keisan/ast/list_assignment.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(assignment, context, lhs, rhs) ⇒ ListAssignment

Returns a new instance of ListAssignment.



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# File 'lib/keisan/ast/list_assignment.rb', line 6

def initialize(assignment, context, lhs, rhs)
  @assignment = assignment
  @context = context
  @lhs = lhs
  @rhs = rhs
end

Instance Attribute Details

#assignment ⇒ Object (readonly)

Returns the value of attribute assignment.



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# File 'lib/keisan/ast/list_assignment.rb', line 4

def assignment
  @assignment
end

#context ⇒ Object (readonly)

Returns the value of attribute context.



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# File 'lib/keisan/ast/list_assignment.rb', line 4

def context
  @context
end

#lhs ⇒ Object (readonly)

Returns the value of attribute lhs.



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# File 'lib/keisan/ast/list_assignment.rb', line 4

def lhs
  @lhs
end

#rhs ⇒ Object (readonly)

Returns the value of attribute rhs.



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# File 'lib/keisan/ast/list_assignment.rb', line 4

def rhs
  @rhs
end

Instance Method Details

#evaluate ⇒ Object 



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# File 'lib/keisan/ast/list_assignment.rb', line 13

def evaluate
  rhs = @rhs.evaluate(context)

  if !rhs.is_a?(List)
    raise Exceptions::InvalidExpression.new("To do multiple assignment, RHS must be a list")
  end
  if lhs.children.size != rhs.children.size
    raise Exceptions::InvalidExpression.new("To do multiple assignment, RHS list must have same length as LHS list")
  end

  i = 0
  while i < lhs.children.size
    lhs_variable = lhs.children[i]
    rhs_assignment = rhs.children[i]
    individual_assignment = Assignment.new(
      children = [lhs_variable, rhs_assignment],
      local: assignment.local,
      compound_operator: assignment.compound_operator
    )
    individual_assignment.evaluate(context)
    i += 1
  end
end