Make ChainRulesCore and InverseFunctions weak dependencies (#153)

* Make ChainRulesCore and InverseFunctions weak dependencies

* Test Julia nightly to check weak dependencies

* Rename extensions

.github/workflows/ci.yml

@@ -29,6 +29,7 @@ jobs:
           - '1.3' # oldest supported version
           - '1.6' # LTS
           - '1' # latest release
+          - 'nightly'
         os:
           - ubuntu-latest
           - macos-latest

Project.toml

@@ -1,6 +1,6 @@
 name = "StatsFuns"
 uuid = "4c63d2b9-4356-54db-8cca-17b64c39e42c"
-version = "1.2.1"
+version = "1.3.0"
 
 [deps]
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"
@@ -12,6 +12,14 @@ Reexport = "189a3867-3050-52da-a836-e630ba90ab69"
 Rmath = "79098fc4-a85e-5d69-aa6a-4863f24498fa"
 SpecialFunctions = "276daf66-3868-5448-9aa4-cd146d93841b"
 
+[weakdeps]
+ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"
+InverseFunctions = "3587e190-3f89-42d0-90ee-14403ec27112"
+
+[extensions]
+StatsFunsChainRulesCoreExt = "ChainRulesCore"
+StatsFunsInverseFunctionsExt = "InverseFunctions"
+
 [compat]
 ChainRulesCore = "1"
 HypergeometricFunctions = "0.3.10"
@@ -24,10 +32,12 @@ SpecialFunctions = "1.8.4, 2.1.4"
 julia = "1.3"
 
 [extras]
+ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"
 ChainRulesTestUtils = "cdddcdb0-9152-4a09-a978-84456f9df70a"
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
+InverseFunctions = "3587e190-3f89-42d0-90ee-14403ec27112"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["ChainRulesTestUtils", "ForwardDiff", "Random", "Test"]
+test = ["ChainRulesCore", "ChainRulesTestUtils", "ForwardDiff", "InverseFunctions", "Random", "Test"]

src/chainrules.jl → ext/StatsFunsChainRulesCoreExt.jl

@@ -1,3 +1,9 @@
+module StatsFunsChainRulesCoreExt
+
+using StatsFuns
+using StatsFuns: digamma
+import ChainRulesCore
+
 ChainRulesCore.@scalar_rule(
     betalogpdf(α::Real, β::Real, x::Number),
     @setup(z = digamma(α + β)),
@@ -76,3 +82,5 @@ ChainRulesCore.@scalar_rule(
         - x * b,
     ),
 )
+
+end # module

src/inverse.jl → ext/StatsFunsInverseFunctionsExt.jl

@@ -1,3 +1,8 @@
+module StatsFunsInverseFunctionsExt
+
+using StatsFuns
+import InverseFunctions
+
 InverseFunctions.inverse(::typeof(normcdf)) = norminvcdf
 InverseFunctions.inverse(::typeof(norminvcdf)) = normcdf
 
@@ -9,3 +14,5 @@ InverseFunctions.inverse(::typeof(norminvlogcdf)) = normlogcdf
 
 InverseFunctions.inverse(::typeof(normlogccdf)) = norminvlogccdf
 InverseFunctions.inverse(::typeof(norminvlogccdf)) = normlogccdf
+
+end # module

src/StatsFuns.jl

@@ -3,8 +3,6 @@ module StatsFuns
 using Base: Math.@horner
 using Reexport
 using SpecialFunctions
-import ChainRulesCore
-import InverseFunctions
 
 # reexports
 @reexport using IrrationalConstants:
@@ -262,7 +260,9 @@ include(joinpath("distrs", "pois.jl"))
 include(joinpath("distrs", "tdist.jl"))
 include(joinpath("distrs", "srdist.jl"))
 
-include("chainrules.jl")
-include("inverse.jl")
+if !isdefined(Base, :get_extension)
+    include("../ext/StatsFunsChainRulesCoreExt.jl")
+    include("../ext/StatsFunsInverseFunctionsExt.jl")
+end
 
 end # module