Class: JSON5::ECMAString

Inherits:
Object
  • Object
show all
Defined in:
lib/json5/ecma_string.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(code_units) ⇒ ECMAString

Returns a new instance of ECMAString.



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# File 'lib/json5/ecma_string.rb', line 7

def initialize(code_units)
  unless code_units.all? { |unit| unit.is_a?(Integer) && unit.between?(0, 0xffff) }
    raise ArgumentError, "code units must be UTF-16 integers"
  end
  @code_units = code_units.dup.freeze
  freeze
end

Instance Attribute Details

#code_units ⇒ Object (readonly)

Returns the value of attribute code_units.



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# File 'lib/json5/ecma_string.rb', line 5

def code_units
  @code_units
end

Instance Method Details

#each_code_unit(&block) ⇒ Object 



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# File 'lib/json5/ecma_string.rb', line 15

def each_code_unit(&block)
  return enum_for(__method__) unless block
  code_units.each(&block)
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/json5/ecma_string.rb', line 24

def empty?
  code_units.empty?
end

#eql?(other) ⇒ Boolean Also known as: ==

Returns:

  • (Boolean) 


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# File 'lib/json5/ecma_string.rb', line 28

def eql?(other)
  other.is_a?(ECMAString) && code_units == other.code_units
end

#hash ⇒ Object 



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# File 'lib/json5/ecma_string.rb', line 33

def hash
  code_units.hash
end

#length ⇒ Object 



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# File 'lib/json5/ecma_string.rb', line 20

def length
  code_units.length
end

#lone_surrogate? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/json5/ecma_string.rb', line 37

def lone_surrogate?
  index = 0
  while index < code_units.length
    unit = code_units[index]
    if surrogate_pair_at?(index)
      index += 2
      next
    end
    return true if high_surrogate?(unit) || low_surrogate?(unit)

    index += 1
  end
  false
end

#to_s ⇒ Object 



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# File 'lib/json5/ecma_string.rb', line 84

def to_s
  to_utf8
end

#to_utf8(lone_surrogate: :error) ⇒ Object 



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# File 'lib/json5/ecma_string.rb', line 52

def to_utf8(lone_surrogate: :error)
  result = String.new(encoding: Encoding::UTF_8)
  index = 0
  while index < code_units.length
    unit = code_units[index]
    if surrogate_pair_at?(index)
      codepoint = 0x10000 + ((unit - 0xd800) << 10) + code_units[index + 1] - 0xdc00
      append_codepoint(result, codepoint)
      index += 2
      next
    end

    if high_surrogate?(unit) || low_surrogate?(unit)
      case lone_surrogate
      when :error
        raise ConversionError.new(
          "lone surrogate cannot be represented as UTF-8",
          code: "lone_surrogate"
        )
      when :replace
        append_codepoint(result, 0xfffd)
      else
        raise ArgumentError, "unknown lone_surrogate policy: #{lone_surrogate.inspect}"
      end
    else
      append_codepoint(result, unit)
    end
    index += 1
  end
  result
end