Class: RDF::Literal::Decimal

Inherits:
Numeric show all
Defined in:
lib/rdf/model/literal/decimal.rb

Overview

A decimal literal.

Examples:

Arithmetic with decimal literals

RDF::Literal(BigDecimal('1.0')) + 0.5   #=> RDF::Literal(BigDecimal('1.5'))
RDF::Literal(BigDecimal('1.0')) - 0.5   #=> RDF::Literal(BigDecimal('0.5'))
RDF::Literal(BigDecimal('1.0')) * 0.5   #=> RDF::Literal(BigDecimal('0.5'))
RDF::Literal(BigDecimal('1.0')) / 0.5   #=> RDF::Literal(BigDecimal('2.0'))

See Also:

Since:

  • 0.2.1

Direct Known Subclasses

Integer

Constant Summary collapse

DATATYPE =

Since:

  • 0.2.1

XSD.decimal
GRAMMAR =

Since:

  • 0.2.1

/^[\+\-]?\d+(\.\d*)?$/.freeze

Constants inherited from RDF::Literal

FALSE, TRUE, ZERO

Instance Attribute Summary

Attributes inherited from RDF::Literal

#datatype, #language

Instance Method Summary collapse

Methods inherited from Numeric

#*, #+, #+@, #-, #-@, #/, #<=>, #==, #to_d, #to_f, #to_i, #to_r

Methods inherited from RDF::Literal

#==, #anonymous?, #canonicalize, #comperable_datatype?, datatyped_class, #eql?, #has_datatype?, #has_language?, #hash, #inspect, #invalid?, #literal?, new, #object, #plain?, #valid?, #validate!, #value

Methods included from Term

#<=>, #==, #constant?, #eql?, #variable?

Methods included from Value

#graph?, #inspect, #inspect!, #iri?, #literal?, #node?, #resource?, #statement?, #to_ntriples, #to_quad, #to_rdf, #type_error, #uri?, #variable?

Constructor Details

#initialize(value, options = {}) ⇒ Decimal

Returns a new instance of Decimal.

Parameters:

  • value (BigDecimal)
  • options (Hash) (defaults to: {}) —

    a customizable set of options

Options Hash (options):

  • :lexical (String) — default: nil

Since:

  • 0.2.1



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# File 'lib/rdf/model/literal/decimal.rb', line 20

def initialize(value, options = {})
  @datatype = RDF::URI(options[:datatype] || self.class.const_get(:DATATYPE))
  @string   = options[:lexical] if options.has_key?(:lexical)
  @string   ||= value if value.is_a?(String)
  @object   = case
    when value.is_a?(BigDecimal) then value
    else BigDecimal(value.to_s)
  end
end

Instance Method Details

#abs ⇒ RDF::Literal

Returns the absolute value of ‘self`.

Returns:

Since:

  • 0.2.3



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# File 'lib/rdf/model/literal/decimal.rb', line 55

def abs
  (d = to_d) && d > 0 ? self : RDF::Literal(d.abs)
end

#canonicalize! ⇒ RDF::Literal

Converts this literal into its canonical lexical representation.

Returns:

See Also:

Since:

  • 0.2.1



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# File 'lib/rdf/model/literal/decimal.rb', line 35

def canonicalize!
  # Can't use simple %f transformation due to special requirements from
  # N3 tests in representation
  @string = begin
    i, f = @object.to_s('F').split('.')
    i.sub!(/^\+?0+(\d)$/, '\1') # remove the optional leading '+' sign and any extra leading zeroes
    f = f[0, 16]                # truncate the fractional part after 15 decimal places
    f.sub!(/0*$/, '')           # remove any trailing zeroes
    f = '0' if f.empty?         # ...but there must be a digit to the right of the decimal point
    "#{i}.#{f}"
  end
  @object = BigDecimal(@string) unless @object.nil?
  self
end

#nonzero? ⇒ Boolean

Returns ‘self` if the value is not zero, `nil` otherwise.

Returns:

Since:

  • 0.2.3



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# File 'lib/rdf/model/literal/decimal.rb', line 73

def nonzero?
  to_d.nonzero? ? self : nil
end

#to_s ⇒ String

Returns the value as a string.

Returns:

  • (String)

See Also:

  • BigDecimal#to_s

Since:

  • 0.2.1



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# File 'lib/rdf/model/literal/decimal.rb', line 82

def to_s
  @string || @object.to_s('F')
end

#zero? ⇒ Boolean

Returns ‘true` if the value is zero.

Returns:

Since:

  • 0.2.3



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# File 'lib/rdf/model/literal/decimal.rb', line 64

def zero?
  to_d.zero?
end