Infer root type from the provided function

.github/workflows/CI.yml

@@ -24,6 +24,8 @@ jobs:
         exclude:
           - os: macOS-latest
             arch: x86
+          - os: windows-latest
+            arch: x86
     steps:
       - uses: actions/checkout@v6
       - uses: julia-actions/setup-julia@v2

Project.toml

@@ -5,6 +5,7 @@ version = "0.6.3"
 [deps]
 BranchAndPrune = "d3bc4f2e-91e6-11e9-365e-cd067da536ce"
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
+InteractiveUtils = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
 IntervalArithmetic = "d1acc4aa-44c8-5952-acd4-ba5d80a2a253"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 Reexport = "189a3867-3050-52da-a836-e630ba90ab69"
@@ -13,6 +14,7 @@ StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 [compat]
 BranchAndPrune = "0.2.1"
 ForwardDiff = "0.10, 1"
+InteractiveUtils = "1.10.0"
 IntervalArithmetic = "1.0.3"
 Reexport = "1"
 StaticArrays = "1"

benchmark/benchmarks.jl

@@ -20,7 +20,7 @@ S = SUITE["Smiley"] = BenchmarkGroup()
 for example in (SmileyExample22, SmileyExample52, SmileyExample54) #, SmileyExample55)
     s = S[example.title] = BenchmarkGroup()
     for contractor in (Newton, Krawczyk)
-        s[string(contractor)] = @benchmarkable roots($(example.f), $(example.region) ; contractor = $contractor, abstol = $tol)
+        s[string(contractor)] = @benchmarkable roots($(example.f), $(example.region) ; contractor = $contractor, abstol = $tol, infer_root_type = false)
     end
 end
 
@@ -39,7 +39,7 @@ L = 5.0
 X = SVector(interval(-L, (L+1)), interval(-L, (L+1)))
 
 for contractor in (Newton, Krawczyk)
-    S[string(contractor)] = @benchmarkable roots($(∇f), $X ; contractor = $contractor, abstol = 1e-5)
+    S[string(contractor)] = @benchmarkable roots($(∇f), $X ; contractor = $contractor, abstol = 1e-5, infer_root_type = false)
 end
 
 
@@ -66,7 +66,7 @@ for (k, dr) in enumerate(dr_functions)
 
     if k != 8  # dr8 is excluded as it has too many roots
         for contractor in (Newton, Krawczyk)
-            s[string(contractor)] = @benchmarkable roots($dr, $X ; contractor = $contractor, abstol = $tol)
+            s[string(contractor)] = @benchmarkable roots($dr, $X ; contractor = $contractor, abstol = $tol, infer_root_type = false)
         end
     end
 end

src/IntervalRootFinding.jl

@@ -7,6 +7,7 @@ using IntervalArithmetic.Symbols
 using BranchAndPrune
 using ForwardDiff
 using ForwardDiff: derivative, jacobian
+using InteractiveUtils
 using StaticArrays
 
 using LinearAlgebra

src/roots.jl

@@ -27,7 +27,7 @@ The returned `RootProblem` is an iterator that give access to the internal
 state of the search during the iteration,
 allowing to add callbacks and logging to the search.
 
-Parameters
+Keyword parameters
 ==========
 - `contractor`: Contractor used to determine the status of a region.
     Must be either `Newton`, `Krawczyk`, or `Bisection`. `Bisection` do not require
@@ -46,6 +46,11 @@ Parameters
     Default: `0.0`.
 - `max_iteration`: The maximum number of iteration, which also corresponds to
     the maximum number of bisections allowed. Default: `100_000`.
+- `infer_root_type`: When true, use the return type of the function as
+    type for the region in the returned roots, avoiding extra conversions
+    during the computation.
+    Otherwise, use the type of the provided region.
+    Default: `true`. Always `false` if the initial region is given as a `Root`.
 - `where_bisect`: Value used to bisect the region. It is used to avoid
     bisecting exactly on zero when starting with symmetrical regions,
     often leading to having a solution directly on the boundary of a region,
@@ -55,7 +60,17 @@ Parameters
     further.
     Default: `[IntervalArithmetic.InconclusiveBooleanOperation]`.
 """
-RootProblem(f, region ; kwargs...) = RootProblem(f, Root(region, :unkown) ; kwargs...)
+function RootProblem(f, region ; infer_root_type = true, kwargs...)
+    if infer_root_type
+        T = last(InteractiveUtils.@code_typed(f(region)))
+        if isconcretetype(T)
+            region = convert(T, region)
+        else
+            @warn "Could not infer the return type of the function (it may be type instable). Got $T"
+        end
+    end
+    RootProblem(f, Root(region, :unkown) ; kwargs...)
+end
 
 function RootProblem(
         f, root::Root ;