Add XPath math functions and constants to Literal::Numeric. PI, #exp, #exp10, #log, #log10, #sqrt, #sin, #cos, #tan, #asin, #acos, #atan, #atan2.

Author: gkellogg

lib/rdf/model/literal/double.rb

@@ -34,6 +34,14 @@ def initialize(value, datatype: nil, lexical: nil, **options)
       end
     end
 
+    # Approximation of the mathematical constant π
+    #
+    # From the XQuery function [math:pi](https://www.w3.org/TR/xpath-functions/#func-math-pi).
+    #
+    # @return [Double]
+    # @see https://www.w3.org/TR/xpath-functions/#func-math-pi
+    PI = Double.new(Math::PI)
+
     ##
     # Converts this literal into its canonical lexical representation.
     #

lib/rdf/model/literal/numeric.rb

@@ -241,6 +241,135 @@ def floor
       self
     end
 
+    ##
+    # Returns the value of `e`<sup>`x`</sup>.
+    #
+    # @return [Double]
+    # @see https://www.w3.org/TR/xpath-functions/#func-math-exp
+    def exp
+      Double.new(Math.exp(self.to_f))
+    end
+
+    ##
+    # Returns the value of `10`<sup>`x`</sup>.
+    #
+    # @return [Double]
+    # @see https://www.w3.org/TR/xpath-functions/#func-math-exp10
+    def exp10
+      Double.new(10**self.to_f)
+    end
+
+    ##
+    # Returns the natural logarithm of the argument.
+    #
+    # @return [Double]
+    # @see https://www.w3.org/TR/xpath-functions/#func-math-log
+    def log
+      Double.new(Math.log(self.to_f))
+    rescue Math::DomainError
+      Double.new(::Float::NAN)
+    end
+
+    ##
+    # Returns the base-ten logarithm of the argument.
+    #
+    # @return [Double]
+    # @see https://www.w3.org/TR/xpath-functions/#func-math-log10
+    def log10
+      Double.new(Math.log10(self.to_f))
+    rescue Math::DomainError
+      Double.new(::Float::NAN)
+    end
+
+    ##
+    # Returns the non-negative square root of the argument.
+    #
+    # @return [Double]
+    # @see https://www.w3.org/TR/xpath-functions/#func-math-sqrt
+    def sqrt
+      Double.new(Math.sqrt(self.to_f))
+    rescue Math::DomainError
+      Double.new(::Float::NAN)
+    end
+
+    ##
+    # Returns the sine of the argument. The argument is an angle in radians.
+    #
+    # @return [Double]
+    # @see https://www.w3.org/TR/xpath-functions/#func-math-sin
+    def sin
+      Double.new(Math.sin(self.to_f))
+    rescue Math::DomainError
+      Double.new(::Float::NAN)
+    end
+
+    ##
+    # Returns the cosine of the argument. The argument is an angle in radians.
+    #
+    # @return [Double]
+    # @see https://www.w3.org/TR/xpath-functions/#func-math-cos
+    def cos
+      Double.new(Math.cos(self.to_f))
+    rescue Math::DomainError
+      Double.new(::Float::NAN)
+    end
+
+    ##
+    # Returns the tangent of the argument. The argument is an angle in radians.
+    #
+    # @return [Double]
+    # @see https://www.w3.org/TR/xpath-functions/#func-math-tan
+    def tan
+      Double.new(Math.tan(self.to_f))
+    rescue Math::DomainError
+      Double.new(::Float::NAN)
+    end
+
+    ##
+    # Returns the arc sine of the argument.
+    #
+    # @return [Double]
+    # @see https://www.w3.org/TR/xpath-functions/#func-math-asin
+    def asin
+      Double.new(Math.asin(self.to_f))
+    rescue Math::DomainError
+      Double.new(::Float::NAN)
+    end
+
+    ##
+    # Returns the arc cosine of the argument.
+    #
+    # @return [Double]
+    # @see https://www.w3.org/TR/xpath-functions/#func-math-acos
+    def acos
+      Double.new(Math.acos(self.to_f))
+    rescue Math::DomainError
+      Double.new(::Float::NAN)
+    end
+
+    ##
+    # Returns the arc tangent of the argument.
+    #
+    # @return [Double]
+    # @see https://www.w3.org/TR/xpath-functions/#func-math-atan
+    def atan
+      Double.new(Math.atan(self.to_f))
+    rescue Math::DomainError
+      Double.new(::Float::NAN)
+    end
+
+    ##
+    # Returns the angle in radians subtended at the origin by the point on a plane with coordinates (x, y) and the positive x-axis.
+    #
+    # @param [#to_f] arg
+    # @return [Double]
+    # @see https://www.w3.org/TR/xpath-functions/#func-math-atan2
+    def atan2(arg)
+      Double.new(Math.atan2(self.to_f, arg.to_f))
+    rescue Math::DomainError
+      Double.new(::Float::NAN)
+    end
+
     ##
     # Returns the value as an integer.
     #