I.7 Arguments coercion for “Result” class operators

One class and some ruby methods are directly defined in ruby language. This part of the programming concerns the operators in which the second argument is a “Result” object, but the first argument has another type (Real, Complex, Array...). Then, a ruby type coercion is performed thanks to the “Result” class “coerce” method. This small part of code allows to perform the operations using the different “Post.op???” methods.

It seems that the built-in “Array” class defines its own “coerce” method, which conflicts with the “Result” coerce mechanism. Therefore, a modification of the “Array” class is restored in version 4.4.4 of FeResPost. (See below.)

This part of FeResPost is programmed in the “FeResPost.rb” file. content looks as follows:

# encoding: utf-8

require "FeResPost.so"

module FeResPost
    class ROpResult
        @x=nil
        def initialize(res)
            @x=res
        end
        def +(other)
            return Post.opAdd(other,@x)
        end
        def -(other)
            return Post.opSub(other,@x)
        end
        def *(other)
            return Post.opMul(other,@x)
        end
        def /(other)
            return Post.opDiv(other,@x)
        end
        def **(other)
            return Post.pow(other,@x)
        end
    end
    class Result
        def coerce(x)
            [ROpResult.new(self),x]
        end
    end # Result
end # FeResPost

class Array
    alias _FeFesPost_old_opAdd +
    alias _FeFesPost_old_opSub -
    alias _FeFesPost_old_opMul *
    def +(second)
        if second.class==Result then
            return Post.opAdd(self,second)
        else
            return self._FeFesPost_old_opAdd(second)
        end
    end
    def -(second)
        if second.class==Result then
            return Post.opSub(self,second)
        else
            return self._FeFesPost_old_opSub(second)
        end
    end
    def *(second)
        if second.class==Result then
            return Post.opMul(self,second)
        else
            return self._FeFesPost_old_opMul(second)
        end
    end
    def /(second)
        if second.class==Result then
            return Post.opDiv(self,second)
        else
            raise "Invalid second operand for / operator"
        end
    end
end # Array

puts "End ' "FeResPost' " module initialization.' n"
puts "' n' n"

Chapter I.7Arguments coercion for “Result” class operators

Chapter I.7
Arguments coercion for “Result” class operators