extend addop and mulop

Author: Will Kimmerer

src/operators/oplist.jl

@@ -767,6 +767,8 @@ for oplus ∈ [(:max, "MAX"), (:min, "MIN"), (:+, "PLUS"), (:*, "TIMES"), (:any,
         rig = Symbol(oplus[2], "_", otimes[2])
         funcquote = quote
             Semirings.Semiring(::typeof($(oplus[1])), ::typeof($(otimes[1]))) = $rig
+            addop(::typeof($rig)) = $(oplus[1])
+            mulop(::typeof($rig)) = $(otimes[1])
         end
         @eval($funcquote)
     end

src/operators/semirings.jl

@@ -280,6 +280,8 @@ function Semirings.Semiring(name::String, add::AbstractMonoid, mul::AbstractBina
     tmul = validtypes(mul)
     trig = intersect(tadd, tmul)
     rig = Semirings.Semiring(name)
+    eval(:(addop(::typeof($rig)) = juliaop($(add))))
+    eval(:(mulop(::typeof($rig)) = juliaop($(mul))))
     for t ∈ trig
         _addsemiring(rig, add[t], mul[t])
     end