Class: Stupidedi::Reader::TokenReader

Inherits:
Object
  • Object
show all
Includes:
Inspect
Defined in:
lib/stupidedi/reader/token_reader.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Inspect

#inspect

Constructor Details

#initialize(input, separators, segment_dict = SegmentDict.empty) ⇒ TokenReader



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# File 'lib/stupidedi/reader/token_reader.rb', line 24

def initialize(input, separators, segment_dict = SegmentDict.empty)
  @input, @separators, @segment_dict =
    input, separators, segment_dict
end

Instance Attribute Details

#inputString, Input (readonly)



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# File 'lib/stupidedi/reader/token_reader.rb', line 16

def input
  @input
end

#segment_dictSegmentDict



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# File 'lib/stupidedi/reader/token_reader.rb', line 22

def segment_dict
  @segment_dict
end

#separatorsSeparators (readonly)



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# File 'lib/stupidedi/reader/token_reader.rb', line 19

def separators
  @separators
end

Instance Method Details

#consume(s) ⇒ Either<TokenReader>

If s occurs within #input, then the input up to and including s is skipped and the remaining input is returned as a new TokenReader wrapped by Either.success. Otherwise, Either::Failure is returned.



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# File 'lib/stupidedi/reader/token_reader.rb', line 101

def consume(s)
  return success(self) if s.empty?

  position = 0
  buffer   = " " * s.length

  while @input.defined_at?(position)
    character = @input.at(position)

    unless is_control?(character)
      # Slide the "window" forward one character
      buffer = buffer.slice(1..-1) + character
    end

    position += 1

    if s == buffer
      return success(advance(position))
    end
  end

  failure("reached end of input without finding #{s.inspect}")
end

#consume_control_chars



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# File 'lib/stupidedi/reader/token_reader.rb', line 82

def consume_control_chars
  position = 0

  while @input.defined_at?(position) and is_control?(@input.at(position))
    position += 1
  end

  if position.zero?
    success(self)
  else
    success(advance(position))
  end
end

#consume_prefix(s) ⇒ Either<TokenReader>

If s is a prefix of #input, then s is skipped and the remaining input is returned as a new TokenReader wrapped by Either.success. Otherwise, an Either::Failure is returned.



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# File 'lib/stupidedi/reader/token_reader.rb', line 56

def consume_prefix(s)
  return success(self) if s.empty?

  position = 0
  buffer   = ""

  while @input.defined_at?(position)
    character = @input.at(position)
    position += 1

    unless is_control?(character)
      buffer = buffer + character

      if s.length == buffer.length
        if s == buffer
          return success(advance(position))
        else
          return failure("found #{buffer.inspect} instead of #{s.inspect}")
        end
      end
    end
  end

  failure("reached end of input without finding #{s.inspect}")
end

#copy(changes = {}) ⇒ TokenReader



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# File 'lib/stupidedi/reader/token_reader.rb', line 30

def copy(changes = {})
  TokenReader.new \
    changes.fetch(:input, @input),
    changes.fetch(:separators, @separators),
    changes.fetch(:segment_dict, @segment_dict)
end

#empty?Boolean



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# File 'lib/stupidedi/reader/token_reader.rb', line 47

def empty?
  @input.empty?
end

#pretty_print(q)



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# File 'lib/stupidedi/reader/token_reader.rb', line 401

def pretty_print(q)
  q.text("TokenReader")
  q.group(2, "(", ")") do
    q.breakable ""

    q.pp @input
    q.text ","
    q.breakable

    q.pp @separators
  end
end

#read_characterEither<Result<String>>

Returns a single character and the remaining input as a Result with a value of the character and a remainder of the reamining input as a new instance of Stupidedi::Reader::TokenReader. If #input has less than a single character, returns an Either::Failure



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# File 'lib/stupidedi/reader/token_reader.rb', line 131

def read_character
  position = 0
  buffer   = ""

  while @input.defined_at?(position)
    character = @input.at(position)
    position += 1

    if is_control?(character)
      next
    end

    return result(character, advance(position))
  end

  failure("less than one character available")
end

#read_component_element(repeatable = false) ⇒ Either<Result<ComponentElementTok, TokenReader>>



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# File 'lib/stupidedi/reader/token_reader.rb', line 345

def read_component_element(repeatable = false)
  position = 0
  buffer   = ""

  while @input.defined_at?(position)
    character = @input.at(position)
    position += 1

    if is_control?(character)
      next
    end

    case character
    when @separators.element,
         @separators.segment,
         @separators.component
      # Don't consume the separator/terminator
      token = component(buffer, @input, @input.drop(position))
      return result(token, advance(position - 1))
    when @separators.repetition
      if repeatable
        # Don't consume the repetition separator
        token = component(buffer, @input, @input.drop(position))
        return result(token, advance(position - 1))
    # else
    #   # @todo: Read this as data but sound the alarms
      end
    end

    buffer = buffer + character
  end

  failure("reached end of input without finding a component data element")
end

#read_component_elements(repeatable = false) ⇒ Either<Result<Array<ComponentElementTok, TokenReader>>>



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# File 'lib/stupidedi/reader/token_reader.rb', line 220

def read_component_elements(repeatable = false)
  read_component_element(repeatable).flatmap do |component, aR|
    aR.read_delimiter.flatmap do |delim, bR|
      case delim
      when @separators.segment,
           @separators.element,
           @separators.repetition
        # This is the last component element within the composite element,
        # so make it into a singleton list and don't consume the delimiter
        result(component.cons, aR)
      when @separators.component
        rest = bR.read_component_elements(repeatable)
        rest.map{|es, _| component.cons(es) }
      end
    end
  end
end

#read_composite_element(repeatable = false) ⇒ Either<Result<CompositeElementTok, TokenReader>>



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# File 'lib/stupidedi/reader/token_reader.rb', line 381

def read_composite_element(repeatable = false)
  read_component_elements(repeatable).flatmap do |components, aR|
    token = composite(components, @input, aR.input)

    aR.read_delimiter.flatmap do |delim, bR|
      case delim
      when @separators.segment,
           @separators.element
        token = token.repeated if repeatable
        result(token, aR)
      when @separators.repetition
        bR.read_composite_element(repeatable).map do |c, cR|
          c.repeated(token)
        end
      end
    end
  end
end

#read_delimiterEither<Result<Character, TokenReader>>



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# File 'lib/stupidedi/reader/token_reader.rb', line 283

def read_delimiter
  position = 0

  while @input.defined_at?(position)
    character = @input.at(position)
    position += 1

    if is_control?(character)
      next
    end

    if is_delimiter?(character)
      return result(character, advance(position))
    else
      return failure("found #{character.inspect} instead of a delimiter")
    end
  end

  failure("reached end of input without finding a delimiter")
end

#read_elements(segment_id, element_uses) ⇒ Either<Result<Array<SimpleElementTok, CompositeElementTok>, TokenReader>>



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# File 'lib/stupidedi/reader/token_reader.rb', line 184

def read_elements(segment_id, element_uses)
  if element_uses.empty?
    read_simple_element
  else
    element_use = element_uses.head
    repeatable  = element_use.repeatable?

    if element_use.composite?
      read_composite_element(repeatable)
    else
      read_simple_element(repeatable)
    end
  end.flatmap do |element, aR|
    aR.read_delimiter.flatmap do |delim, bR|
      case delim
      when @separators.segment
        remainder =
          if segment_id == :IEA
            bR.stream
          else
            bR
          end

        # This is the last element before the segment terminator, make
        # it into a singleton list and _do_ consume the delimiter
        result(element.cons, remainder)
      when @separators.element
        # There is another element following the delimiter
        rest = bR.read_elements(segment_id, element_uses.tail)
        rest.map{|es, _| element.cons(es) }
      end
    end
  end
end

#read_segmentEither<Result<SegmentTok, TokenReader>>



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# File 'lib/stupidedi/reader/token_reader.rb', line 150

def read_segment
  consume_control_chars.flatmap do |start|
    # We might start reading a segment at "\nNM1...", where the "\n" is on
    # line 5, but "NM1" is on line 6. So to ensure the segment position is
    # line 6, we start with consume_control_characters.
    start.read_segment_id.flatmap do |segment_id, aR|
      if @segment_dict.defined_at?(segment_id)
        element_uses = @segment_dict.at(segment_id).element_uses
      else
        element_uses = []
      end

      aR.read_delimiter.flatmap do |delim, bR|
        case delim
        when @separators.element
          rest = bR.read_elements(segment_id, element_uses)
          rest.map{|es, cR| segment(segment_id, start.input, cR.input, es) }
        when @separators.segment
          remainder =
            if segment_id == :IEA
              bR.stream
            else
              bR
            end

          # Consume the segment terminator
          result(segment(segment_id, start.input, bR.input), remainder)
        end
      end
    end
  end
end

#read_segment_idEither<Result<Symbol, TokenReader>>



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# File 'lib/stupidedi/reader/token_reader.rb', line 239

def read_segment_id
  position = 0
  buffer   = ""

  while true
    unless @input.defined_at?(position)
      return eof("reached end of input without finding a segment identifier")
    end

    character = @input.at(position)
    position += 1

    if is_delimiter?(character)
      break
    end

    unless is_control?(character)
      if buffer.length == 3
        break
      end

      buffer = buffer + character
    end
  end

  # We only arrive here if {character} is a delimiter, or if we read
  # three characters into {buffer} and an additional into {character}
  if buffer =~ SEGMENT_ID
    remainder = advance(position - 1)

    case character
    when @separators.segment,
         @separators.element
      # Don't consume the delimiter
      result(buffer.upcase.to_sym, remainder)
    else
      failure("found #{character.inspect} following segment identifier")
    end
  else
    failure("found #{(buffer + character).inspect} instead of segment identifier")
  end
end

#read_simple_element(repeatable = false) ⇒ Either<Result<SimpleElementToken, TokenReader>>



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# File 'lib/stupidedi/reader/token_reader.rb', line 305

def read_simple_element(repeatable = false)
  position = 0
  buffer   = ""

  while @input.defined_at?(position)
    character = @input.at(position)
    position += 1

    if is_control?(character)
      next
    end

    case character
    when @separators.segment,
         @separators.element
      # These delimiters mark the end of the element. We don't consume
      # the delimiter because the next reader can use the delimiter to
      # know which token to next expect.
      token = simple(buffer, @input, @input.drop(position))
      token = token.repeated if repeatable
      return result(token, advance(position - 1))
    when @separators.repetition
      if repeatable
        token = simple(buffer, @input, @input.drop(position))
        rest  = advance(position).read_simple_element(repeatable)
        return rest.map{|e, _| e.repeated(token) }
    # else
    #   # @todo: Read this as data but sound the alarms
      end
  # when @separators.component
  #   # @todo: Read this as data but sound the alarms
    end

    buffer = buffer + character
  end

  failure("reached end of input without finding a simple data element")
end

#streamStreamReader



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# File 'lib/stupidedi/reader/token_reader.rb', line 43

def stream
  StreamReader.new(@input)
end

#stream?Boolean



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# File 'lib/stupidedi/reader/token_reader.rb', line 38

def stream?
  false
end