Class: Expressionist::Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/expressionist/parser.rb

Instance Method Summary collapse

Constructor Details

#initialize(expression) ⇒ Parser

Returns a new instance of Parser.



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# File 'lib/expressionist/parser.rb', line 10

def initialize(expression)
  @parsed = nil
  @compiled = nil
  @executable = nil

  case expression
  when String
    @expression = expression
  when Function
    @compiled   = expression
  when Array
    @executable = expression
  else
    raise ArgumentError, "Unknown expression type: #{expression}"
  end
end

Instance Method Details

#compiled ⇒ Object

Raises:

  • (RuntimeError) 


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# File 'lib/expressionist/parser.rb', line 36

def compiled
  raise RuntimeError, 'Raw nor compiled form was passed' unless @compiled || parsed
  @compiled ||= Transformer.new.apply(parsed)
end

#executable ⇒ Object

Raises:

  • (RuntimeError) 


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# File 'lib/expressionist/parser.rb', line 41

def executable
  raise RuntimeError, 'Compiled nor executable form was passed' unless @executable || compiled
  @executable ||= compiled.to_a
end

#parsed ⇒ Object 



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# File 'lib/expressionist/parser.rb', line 27

def parsed
  raise RuntimeError, 'Expression was not passed' unless @expression
  @parsed ||= Grammar.new.parse(@expression)
rescue Parslet::ParseFailed => e
  # puts expression
  # puts e.parse_failure_cause.ascii_tree
  raise ArgumentError, "Invalid expression: #{@expression}"
end