Backport #605 (dual exponent) to release-0.10 (#614)

* dual exponent (#605)

* add exponent(::Dual)

* revert spacing

* tell CI to run on this branch

* version bump

Co-authored-by: Paul Tiede <ptiede91@gmail.com>

.github/workflows/ci.yml

@@ -3,9 +3,11 @@ on:
   pull_request:
     branches:
       - master
+      - release-0.10
   push:
     branches:
       - master
+      - release-0.10
     tags: '*'
 jobs:
   test:
@@ -17,6 +19,7 @@ jobs:
       matrix:
         version:
           - '1.0'
+          - '1.6'
           - '1'
           - 'nightly'
         os:

Project.toml

@@ -1,6 +1,6 @@
 name = "ForwardDiff"
 uuid = "f6369f11-7733-5829-9624-2563aa707210"
-version = "0.10.32"
+version = "0.10.34"
 
 [deps]
 CommonSubexpressions = "bbf7d656-a473-5ed7-a52c-81e309532950"

src/dual.jl

@@ -332,6 +332,8 @@ Base.fld(x::Dual, y::Dual) = fld(value(x), value(y))
 
 Base.cld(x::Dual, y::Dual) = cld(value(x), value(y))
 
+Base.exponent(x::Dual) = exponent(value(x))
+
 if VERSION ≥ v"1.4"
     Base.div(x::Dual, y::Dual, r::RoundingMode) = div(value(x), value(y), r)
 else

test/DualTest.jl

@@ -155,6 +155,10 @@ for N in (0,3), M in (0,4), V in (Int, Float32)
         @test fld(FDNUM, PRIMAL2) === fld(PRIMAL, PRIMAL2)
         @test fld(PRIMAL, FDNUM2) === fld(PRIMAL, PRIMAL2)
 
+        @test exponent(FDNUM) === exponent(PRIMAL)
+        @test exponent(FDNUM2) === exponent(PRIMAL2)
+        @test exponent(NESTED_FDNUM) === exponent(PRIMAL)
+
         @test cld(FDNUM, FDNUM2) === cld(PRIMAL, PRIMAL2)
         @test cld(FDNUM, PRIMAL2) === cld(PRIMAL, PRIMAL2)
         @test cld(PRIMAL, FDNUM2) === cld(PRIMAL, PRIMAL2)