Class: Kalculator::Evaluator

Inherits:
Object
  • Object
show all
Defined in:
lib/kalculator/evaluator.rb

Instance Method Summary collapse

Constructor Details

#initialize(data_source, custom_functions = {}) ⇒ Evaluator

Returns a new instance of Evaluator.



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# File 'lib/kalculator/evaluator.rb', line 4

def initialize(data_source, custom_functions = {})

  @data_source = data_source
  @functions = Kalculator::BUILT_IN_FUNCTIONS.merge(custom_functions)
end

Instance Method Details

#!=(_, left, right, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 65

def !=(_, left, right, metadata)
  evaluate(left) != evaluate(right)
end

#*(_, left, right, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 37

def *(_, left, right, metadata)
  evaluate(left) * evaluate(right)
end

#+(_, left, right, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 29

def +(_, left, right, metadata)
  evaluate(left) + evaluate(right)
end

#-(_, left, right, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 33

def -(_, left, right, metadata)
  evaluate(left) - evaluate(right)
end

#/(_, left, right, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 41

def /(_, left, right, metadata)
  evaluate(left) / evaluate(right)
end

#<(_, left, right, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 53

def <(_, left, right, metadata)
  evaluate(left) < evaluate(right)
end

#<=(_, left, right, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 57

def <=(_, left, right, metadata)
  evaluate(left) <= evaluate(right)
end

#==(_, left, right, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 61

def ==(_, left, right, metadata)
  evaluate(left) == evaluate(right)
end

#>(_, left, right, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 45

def >(_, left, right, metadata)
  evaluate(left) > evaluate(right)
end

#>=(_, left, right, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 49

def >=(_, left, right, metadata)
  evaluate(left) >= evaluate(right)
end

#access(_, identifier, object, metadata) ⇒ Object

Raises:



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# File 'lib/kalculator/evaluator.rb', line 15

def access(_, identifier, object, metadata)
  a = evaluate(object)
  if(a.key?(identifier))
    b =a[identifier]
    if(b.is_a?(Kalculator::Pointer))
      b = @data_source[b.p]
    end
    if(b.is_a?(Kalculator::AnonymousPointer))
      b = b.p
    end
    return b
  end
  raise UndefinedVariableError.new(metadata), "object #{a} doesn't have attribute #{identifier}"
end

#and(_, left, right, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 69

def and(_, left, right, metadata)
  evaluate(left) && evaluate(right)
end

#boolean(_, boolean, _, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 77

def boolean(_, boolean,_, metadata)
  boolean
end

#evaluate(ast) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 10

def evaluate(ast)

  send(ast.first, *ast)
end

#exists(_, variable, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 81

def exists(_, variable, metadata)
  @data_source.key?(variable)
end

#fn_call(_, fn_name, expressions, metadata) ⇒ Object

Raises:



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# File 'lib/kalculator/evaluator.rb', line 85

def fn_call(_, fn_name, expressions, metadata)
  key = [fn_name, expressions.count]
  fn = @functions[key]
  raise UndefinedFunctionError.new(metadata), "no such function #{fn_name}/#{expressions.count}" if fn.nil?
  args = expressions.map{|expression| evaluate(expression) }
  return fn.call(*args)
end

#if(_, condition, true_clause, false_clause, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 93

def if(_, condition, true_clause, false_clause, metadata)
  if evaluate(condition)
    evaluate(true_clause)
  else
    evaluate(false_clause)
  end
end

#list(_, expressions, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 101

def list(_, expressions, metadata)
  expressions.map{|expression| evaluate(expression) }
end

#not(_, expression, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 105

def not(_, expression, metadata)
  bool = evaluate(expression)
  !bool
end

#null(_, _, _, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 110

def null(_, _,_, metadata)
  nil
end

#number(_, number, _, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 114

def number(_, number,_, metadata)
  number
end

#or(_, left, right, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 73

def or(_, left, right, metadata)
  evaluate(left) || evaluate(right)
end

#percent(_, percent, _, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 118

def percent(_, percent,_, metadata)
  percent / 100.0
end

#string(_, string, _, metadata) ⇒ Object 



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# File 'lib/kalculator/evaluator.rb', line 122

def string(_, string,_, metadata)
  string
end

#variable(_, name, metadata) ⇒ Object

Raises:



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# File 'lib/kalculator/evaluator.rb', line 126

def variable(_, name, metadata)
  raise UndefinedVariableError.new(metadata), "undefined variable #{name}" unless @data_source.key?(name)
  a = @data_source[name]
  if(a.is_a?(Pointer))
    a = @data_source[a.p]
  end
  if(a.is_a?(Kalculator::AnonymousPointer))
    a = a.p
  end
  return a
end