feat: share the termination condition code in NonlinearSolve and Simp…

…leNonlinearSolve

lib/NonlinearSolveBase/src/NonlinearSolveBase.jl

@@ -8,16 +8,17 @@ using LinearAlgebra: norm
 using Markdown: @doc_str
 using RecursiveArrayTools: AbstractVectorOfArray, ArrayPartition
 using SciMLBase: SciMLBase, ReturnCode, AbstractODEIntegrator, AbstractNonlinearProblem,
-                 AbstractNonlinearFunction, @add_kwonly, StandardNonlinearProblem,
-                 NullParameters, NonlinearProblem, isinplace
+                 NonlinearProblem, NonlinearLeastSquaresProblem, AbstractNonlinearFunction,
+                 @add_kwonly, StandardNonlinearProblem, NullParameters, NonlinearProblem,
+                 isinplace
 using StaticArraysCore: StaticArray
 
 include("public.jl")
 include("utils.jl")
 
+include("immutable_problem.jl")
 include("common_defaults.jl")
 include("termination_conditions.jl")
-include("immutable_problem.jl")
 
 # Unexported Public API
 @compat(public, (L2_NORM, Linf_NORM, NAN_CHECK, UNITLESS_ABS2, get_tolerance))

lib/NonlinearSolveBase/src/termination_conditions.jl

@@ -245,3 +245,37 @@ end
 function check_convergence(mode::AbsNormModes, duₙ, _, __, abstol, ___)
     return Utils.apply_norm(mode.internalnorm, duₙ) ≤ abstol
 end
+
+# High-Level API with defaults.
+## This is mostly for internal usage in NonlinearSolve and SimpleNonlinearSolve
+function default_termination_mode(
+        ::Union{ImmutableNonlinearProblem, NonlinearProblem}, ::Val{:simple})
+    return AbsNormTerminationMode(Base.Fix1(maximum, abs))
+end
+function default_termination_mode(::NonlinearLeastSquaresProblem, ::Val{:simple})
+    return AbsNormTerminationMode(Base.Fix2(norm, 2))
+end
+
+function default_termination_mode(
+        ::Union{ImmutableNonlinearProblem, NonlinearProblem}, ::Val{:regular})
+    return AbsNormSafeBestTerminationMode(Base.Fix1(maximum, abs); max_stalled_steps = 32)
+end
+
+function default_termination_mode(::NonlinearLeastSquaresProblem, ::Val{:regular})
+    return AbsNormSafeBestTerminationMode(Base.Fix2(norm, 2); max_stalled_steps = 32)
+end
+
+function init_termination_cache(
+        prob::AbstractNonlinearProblem, abstol, reltol, du, u, ::Nothing, callee::Val)
+    return init_termination_cache(
+        prob, abstol, reltol, du, u, default_termination_mode(prob, callee), callee)
+end
+
+function init_termination_cache(::AbstractNonlinearProblem, abstol, reltol, du,
+        u, tc::AbstractNonlinearTerminationMode, ::Val)
+    T = promote_type(eltype(du), eltype(u))
+    abstol = get_tolerance(abstol, T)
+    reltol = get_tolerance(reltol, T)
+    cache = init(du, u, tc; abstol, reltol)
+    return abstol, reltol, cache
+end