Class: Dentaku::PrintVisitor

Inherits:
Object
  • Object
show all
Defined in:
lib/dentaku/print_visitor.rb

Instance Method Summary collapse

Constructor Details

#initialize(node) ⇒ PrintVisitor

Returns a new instance of PrintVisitor.



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# File 'lib/dentaku/print_visitor.rb', line 3

def initialize(node)
  @output = ''
  node.accept(self)
end

Instance Method Details

#should_output?(node, precedence, output_on_equal) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dentaku/print_visitor.rb', line 28

def should_output?(node, precedence, output_on_equal)
  return false unless node.is_a?(Dentaku::AST::Operation)

  target_precedence = node.class.precedence
  target_precedence < precedence || (output_on_equal && target_precedence == precedence)
end

#to_s ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 108

def to_s
  @output
end

#visit_access(node) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 85

def visit_access(node)
  node.structure.accept(self)
  @output << "["
  node.index.accept(self)
  @output << "]"
end

#visit_array(node) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 104

def visit_array(node)
  @output << node.value.to_s
end

#visit_case(node) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 46

def visit_case(node)
  @output << "CASE "
  node.switch.accept(self)
  node.conditions.each { |c| c.accept(self) }
  node.else && node.else.accept(self)
  @output << " END"
end

#visit_case_conditional(node) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 58

def visit_case_conditional(node)
  node.when.accept(self)
  node.then.accept(self)
end

#visit_else(node) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 73

def visit_else(node)
  @output << " ELSE "
  node.node.accept(self)
end

#visit_function(node) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 35

def visit_function(node)
  @output << node.name
  @output << "("
  arg_count = node.args.length
  node.args.each_with_index do |a, index|
    a.accept(self)
    @output << ", " unless index >= arg_count - 1
  end
  @output << ")"
end

#visit_identifier(node) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 96

def visit_identifier(node)
  @output << node.identifier
end

#visit_literal(node) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 92

def visit_literal(node)
  @output << node.quoted
end

#visit_negation(node) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 78

def visit_negation(node)
  @output << "-"
  @output << "(" unless node.node.is_a? Dentaku::AST::Literal
  node.node.accept(self)
  @output << ")" unless node.node.is_a? Dentaku::AST::Literal
end

#visit_nil(node) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 100

def visit_nil(node)
  @output << "NULL"
end

#visit_operand(node, precedence, prefix: "", suffix: "", dir: :none) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 20

def visit_operand(node, precedence, prefix: "", suffix: "", dir: :none)
  @output << prefix
  @output << "(" if should_output?(node, precedence, dir == :right)
  node.accept(self)
  @output << ")" if should_output?(node, precedence, dir == :right)
  @output << suffix
end

#visit_operation(node) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 8

def visit_operation(node)
  if node.left
    visit_operand(node.left, node.class.precedence, suffix: " ", dir: :left)
  end

  @output << node.display_operator

  if node.right
    visit_operand(node.right, node.class.precedence, prefix: " ", dir: :right)
  end
end

#visit_switch(node) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 54

def visit_switch(node)
  node.node.accept(self)
end

#visit_then(node) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 68

def visit_then(node)
  @output << " THEN "
  node.node.accept(self)
end

#visit_when(node) ⇒ Object 



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# File 'lib/dentaku/print_visitor.rb', line 63

def visit_when(node)
  @output << " WHEN "
  node.node.accept(self)
end