Class: OsMapRef::InputProcessor

Inherits:
Object
  • Object
show all
Defined in:
lib/os_map_ref/input_processor.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(input) ⇒ InputProcessor

Returns a new instance of InputProcessor.



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# File 'lib/os_map_ref/input_processor.rb', line 7

def initialize(input)
  @input = input
end

Instance Attribute Details

#input ⇒ Object (readonly)

Returns the value of attribute input.



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# File 'lib/os_map_ref/input_processor.rb', line 5

def input
  @input
end

Instance Method Details

#determine_easting_and_northing ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 83

def determine_easting_and_northing
  match = easting_northing_pattern.match input
  easting = match[1]
  northing = match[3]
  length = northing.length > easting.length ? extended_length : normal_length
  [
    easting.ljust(normal_length, padding),
    northing.ljust(length, padding)
  ]
end

#determine_map_reference_elements ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 45

def determine_map_reference_elements
  match = map_reference_pattern.match input
  (1..3).collect { |n| match[n] }
end

#easting_and_northing ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 79

def easting_and_northing
  @easting_and_northing ||= determine_easting_and_northing
end

#easting_northing_params ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 26

def easting_northing_params
  {
    easting: easting_and_northing[0],
    northing: easting_and_northing[1]
  }
end

#easting_northing_pattern ⇒ Object

Matches are: 1: First digits which may be followed with a decimal point and more digits 2: The decimal point and trailing digits from first match (if present) 3: Second digits which may be followed with a decimal point and more digits 4: The decimal point and trailing digits from second match (if present) So: “1234.5, 6789.0” –> 1: “1234.5”, 2: “.5”, 3: “6789.0”, 4: “.0” “1234 6789” –> 1: “1234”, 2: nil, 3: “6789”, 4: nil



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# File 'lib/os_map_ref/input_processor.rb', line 114

def easting_northing_pattern
  eastings = /\d{3,6}/  # 3 to 6 digits
  northings = /\d{3,7}/ # 3 to 7 digits
  decimals = /\.\d+/    # decimal point and trailing digits
  separator = /[\,\s]+/ # commas or spaces
  /(#{eastings}(#{decimals})?)#{separator}(#{northings}(#{decimals})?)/
end

#extended_length ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 94

def extended_length
  normal_length + 1
end

#grid_letters ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 50

def grid_letters
  map_reference_elements[0]
end

#map_reference_easting ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 54

def map_reference_easting
  map_reference_elements[1]
end

#map_reference_elements ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 41

def map_reference_elements
  @map_reference_elements ||= determine_map_reference_elements
end

#map_reference_northing ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 58

def map_reference_northing
  map_reference_elements[2]
end

#map_reference_params ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 22

def map_reference_params
  { map_reference: processed_map_reference }
end

#map_reference_pattern ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 75

def map_reference_pattern
  /([a-zA-Z]{2})\s*(\d{3,5})\s*(\d{3,6})/
end

#normal_length ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 98

def normal_length
  6
end

#northing_longer_than_easting? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/os_map_ref/input_processor.rb', line 71

def northing_longer_than_easting?
  map_reference_northing.length > map_reference_easting.length
end

#padded_map_reference_easting ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 62

def padded_map_reference_easting
  map_reference_easting.ljust((normal_length - 1), padding)
end

#padded_map_reference_northing ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 66

def padded_map_reference_northing
  target_length = northing_longer_than_easting? ? extended_length : normal_length
  map_reference_northing.ljust((target_length - 1), padding)
end

#padding ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 102

def padding
  "0"
end

#params ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 11

def params
  case input
  when map_reference_pattern
    map_reference_params
  when easting_northing_pattern
    easting_northing_params
  else
    raise OsMapRef::Error, "Unable to process input #{input}"
  end
end

#processed_map_reference ⇒ Object 



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# File 'lib/os_map_ref/input_processor.rb', line 33

def processed_map_reference
  [
    grid_letters.upcase,
    padded_map_reference_easting,
    padded_map_reference_northing
  ].join(" ")
end