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Re-exported SciMLBase API

Every OrdinaryDiffEq solver sublibrary (OrdinaryDiffEqTsit5, OrdinaryDiffEqFeagin, …) re-exports part of SciMLBase, so that using OrdinaryDiffEqFeagin alone is enough to write and run a solve, exactly as using DifferentialEquations is. This page defines which names that is, and why.

Sublibraries that name their re-exports use exactly the list below. The remaining sublibraries still re-export all of SciMLBase, which is a superset of this list, and are migrated to it separately so that no release both narrows exports and changes behaviour.

The rule

A SciMLBase name is re-exported if and only if it belongs to the user-facing common interface — the part of SciMLBase a user writes in a script. Concretely, a name is re-exported when it falls in one of these five closed categories:

  1. Problem and function types — the concrete SciMLBase types in the Common Interface API. This is the set OrdinaryDiffEq uses for ODEs, split ODEs, second-order and dynamical ODEs, DAEs, discrete maps, and ensembles. Problem domains solved by other libraries, such as optimization, nonlinear equations, SDEs, DDEs, and boundary value problems, are not re-exported.
  2. Solving and solution inspection — solve, solve!, init, step!, remake, ReturnCode, successful_retcode, the statistics types, and the specialization and initialization options accepted by problem constructors and solve.
  3. Callbacks — the callback types and their root-finding options.
  4. Integrator interface — the mutating and querying verbs documented for use inside a callback or an init/step! loop (u_modified!, add_tstop!, set_u!, get_du, …).
  5. Ensembles — the ensemble algorithms and EnsembleAnalysis.

Everything else SciMLBase exports stays behind the SciMLBase. qualifier. Those exclusions are categories, not case-by-case decisions:

  • Abstract types (AbstractODEProblem, AbstractDEAlgorithm, …) — dispatch hooks for package authors, not something a user constructs.
  • Solver-author API — trait predicates (isinplace, has_jac, allowscomplex, requiresgradient, …), construction helpers (build_solution), wrapper and cache types, and macros. These are the interface a new solver package implements, not the interface a user calls.
  • Internal dispatch tags (StandardODEProblem, …AliasSpecifier internals, originator types).
  • Other problem domains (OptimizationProblem, NonlinearProblem, SDEProblem, …) — their solver packages own those interfaces.

Two consequences worth stating explicitly, because they are the point of having a rule:

  • The list follows real usage. It is not "whatever this package happened to export before"; the problem and function types come from OrdinaryDiffEq's documented common interface.
  • The list is uniform. Every solver sublibrary re-exports the same names. A name is never available from one sublibrary and missing from another, so moving a script between solver packages never produces an UndefVarError.

The rule is enforced, not just described: test/qa/reexport_tests.jl reads the Common Interface API and asserts that its concrete SciMLBase problem and function types exactly match this page. It also checks that the enumerated names are exported by SciMLBase and that every selective sublibrary uses exactly the same list.

Do not rely on using for solver names

Only the names below come from SciMLBase. Algorithm names (Tsit5, Feagin14, FBDF, …) come from the solver sublibrary that defines them, and everything else in SciMLBase remains reachable as SciMLBase.name.

The re-exported names

Problem and function types

DAEProblem, DiscreteProblem, DynamicalODEProblem, EnsembleProblem, ODEProblem,
SecondOrderODEProblem, SplitODEProblem, DAEFunction, DiscreteFunction,
DynamicalODEFunction, ODEFunction, SplitFunction

Solving and solution inspection

solve, solve!, init, step!,
remake, ReturnCode, successful_retcode, DEStats,
NLStats, NullParameters, AutoSpecialize, FullSpecialize,
NoSpecialize, FunctionWrapperSpecialize, CheckInit, NoInit,
OverrideInit

Callbacks

CallbackSet, ContinuousCallback, DiscreteCallback, VectorContinuousCallback,
LeftRootFind, RightRootFind, NoRootFind

Integrator interface

add_saveat!, add_tstop!, auto_dt_reset!, change_t_via_interpolation!,
check_error, check_error!, first_tstop, get_dt,
get_du, get_du!, get_proposed_dt, get_tmp_cache,
pop_tstop!, reinit!, savevalues!, set_abstol!,
set_proposed_dt!, set_reltol!, set_t!, set_u!,
set_ut!, terminate!, u_modified!

Ensembles

EnsembleAnalysis, EnsembleDistributed, EnsembleSerial, EnsembleSplitThreads,
EnsembleSummary, EnsembleThreads