Trimming dependencies

[longemen3000]

Transducers should reduce their dependencies, as pointed in the zulip channel. some cases are LinearAlgebra, Test and Markdown, here is an analysis on those dependencies, (done by calling Pkg.why and looking at each pkg code)

LinearAlgebra:

  Transducers → Accessors → ConstructionBase → LinearAlgebra
  Transducers → Accessors → LinearAlgebra
  Transducers → Adapt → LinearAlgebra
  Transducers → BangBang → Accessors → ConstructionBase → LinearAlgebra
  Transducers → BangBang → Accessors → LinearAlgebra
  Transducers → BangBang → ConstructionBase → LinearAlgebra
  Transducers → BangBang → LinearAlgebra
  Transducers → ConstructionBase → LinearAlgebra
  Transducers → MicroCollections → Accessors → ConstructionBase → LinearAlgebra
  Transducers → MicroCollections → Accessors → LinearAlgebra
  Transducers → MicroCollections → BangBang → Accessors → ConstructionBase → LinearAlgebra
  Transducers → MicroCollections → BangBang → Accessors → LinearAlgebra
  Transducers → MicroCollections → BangBang → ConstructionBase → LinearAlgebra
  Transducers → MicroCollections → BangBang → LinearAlgebra
  Transducers → SplittablesBase → Setfield → ConstructionBase → LinearAlgebra
  Transducers → Tables → LinearAlgebra

filtering for duplicates:

ConstructionBase → LinearAlgebra
Accessors → LinearAlgebra
Adapt → LinearAlgebra
BangBang → LinearAlgebra
Tables → LinearAlgebra

the situation is the following:

• ConstructionBase: uses linear algebra for some constructors, ConstructionBase should be defining an extension
• Adapt: needs linear algebra, transducers should define an extension
• Accessors LinearAlgebra loaded via ext (EDIT: code is loaded unconditionally, see Errors in extensions during precompilation  JuliaObjects/Accessors.jl#127)
• BangBang : https://github.com/JuliaFolds2/BangBang.jl/blob/master/src/linearalgebra.jl .I don't know what to do about this, seems exported functionality.
• Tables: loads linear algebra (i dont't know where), and transducers seems to use it (?):

  Transducers.jl/src/basics.jl

  Lines 28 to 31 in d264b62

  	function _materializer(xs)
  	T = Tables.materializer(xs)
  	return T isa Type ? T : _materializer(typeof(xs))
  	end

Test

  Transducers → Accessors → InverseFunctions → Test
  Transducers → Accessors → Test
  Transducers → BangBang → Accessors → InverseFunctions → Test
  Transducers → BangBang → Accessors → Test
  Transducers → MicroCollections → Accessors → InverseFunctions → Test
  Transducers → MicroCollections → Accessors → Test
  Transducers → MicroCollections → BangBang → Accessors → InverseFunctions → Test
  Transducers → MicroCollections → BangBang → Accessors → Test
  Transducers → SplittablesBase → Test

filtering duplicates:

InverseFunctions → Test
Accessors → Test
SplittablesBase → Test

the situation here is the following:

• InverseFunctions: exports test functionality (fixed by Make Test a weak dependency JuliaMath/InverseFunctions.jl#52)
• Accessors: loaded via ext (EDIT: code is loaded unconditionally, see Errors in extensions during precompilation  JuliaObjects/Accessors.jl#127) (being worked on in Don't make Test a dependency JuliaObjects/Accessors.jl#164)
• SplittablesBase: there is some testing functionality (that was being moved to SplittablesTesting but the code still recides in SplittablesBase. the best option here would be to make a breaking release, moving all the testing code to SplittablesTesting (that would also require moving SplittablesTesting to JuliaFolds2

Markdown:

Transducers → Accessors → InverseFunctions → Test → InteractiveUtils → Markdown
  Transducers → Accessors → MacroTools → Markdown
  Transducers → Accessors → Markdown
  Transducers → Accessors → Test → InteractiveUtils → Markdown
  Transducers → BangBang → Accessors → InverseFunctions → Test → InteractiveUtils → Markdown
  Transducers → BangBang → Accessors → MacroTools → Markdown
  Transducers → BangBang → Accessors → Markdown
  Transducers → BangBang → Accessors → Test → InteractiveUtils → Markdown
  Transducers → Markdown
  Transducers → MicroCollections → Accessors → InverseFunctions → Test → InteractiveUtils → Markdown
  Transducers → MicroCollections → Accessors → MacroTools → Markdown
  Transducers → MicroCollections → Accessors → Markdown
  Transducers → MicroCollections → Accessors → Test → InteractiveUtils → Markdown
  Transducers → MicroCollections → BangBang → Accessors → InverseFunctions → Test → InteractiveUtils → Markdown
  Transducers → MicroCollections → BangBang → Accessors → MacroTools → Markdown
  Transducers → MicroCollections → BangBang → Accessors → Markdown
  Transducers → MicroCollections → BangBang → Accessors → Test → InteractiveUtils → Markdown
  Transducers → SplittablesBase → Setfield → MacroTools → Markdown
  Transducers → SplittablesBase → Test → InteractiveUtils → Markdown

filtering for duplicates

Test → InteractiveUtils → Markdown
MacroTools → Markdown
Accessors → Markdown
Transducers → Markdown

• Test: if we remove that dependency, we handle this for free
• MacroTools: used as direct dependency, i don't know where 😬
• Accessors: used in their init file
• Transducers: used as direct dependency