Automatically re-export sub-packages

Using a re-export macro allows us to add functions e.g. to
QuantumControlBase and have those automatically be available in
QuantumControl.

Author: goerz

src/QuantumControl.jl

@@ -1,51 +1,32 @@
 module QuantumControl
+include("reexport.jl")
 
 using QuantumPropagators
 export propagate, propstep!, propstep
 
 using QuantumControlBase
-export ControlProblem, Objective, WeightedObjective, liouvillian
-export discretize, discretize_on_midpoints, getcontrols, get_control_parameters
-export get_tlist_midpoints
-export propagate_objective
-export optimize, @optimize_or_load, optimization_savename, load_optimization
-export default_optimization_savename_kwargs
-export chain_infohooks
+@reexport_members(QuantumControlBase)
 
 module Shapes
+    # we need `QuantumControlBase.Shapes` to be available under a name that
+    # doesn't clash with `QuantumControl.Shapes` in order for the
+    # `@reexport_members` macro to work correctly
+    using QuantumControlBase: Shapes as QuantumControlBase_Shapes
     using QuantumControlBase.Shapes
-    export flattop, box, blackman
+    include("reexport.jl")
+    @reexport_members(QuantumControlBase_Shapes)
 end
 
 module Functionals
+    using QuantumControlBase: Functionals as QuantumControlBase_Functionals
     using QuantumControlBase.Functionals
-    export F_ss, J_T_ss, chi_ss!, F_sm, J_T_sm, chi_sm!, F_re, J_T_re, chi_re!
-    export grad_J_T_sm!
+    include("reexport.jl")
+    @reexport_members(QuantumControlBase_Functionals)
 end
 
 using Krotov
 using GRAPE
 
-using Pkg
-using UUIDs
-
-"""Print the versions of the packages constituting QuantumControl."""
-function print_versions()
-    project_toml = Pkg.TOML.parsefile(joinpath(@__DIR__, "..", "Project.toml"))
-    version = project_toml["version"]
-    direct_deps = project_toml["deps"]
-    deps = Pkg.dependencies()
-    pkg_names = [name for name in keys(direct_deps) if name ∉ ["Pkg", "UUIDs"]]
-    col_width = maximum([length(name) for name in pkg_names])
-    for name in reverse(pkg_names)
-        pkginfo = deps[UUIDs.UUID(direct_deps[name])]
-        if pkginfo.is_tracking_path
-            println("$(rpad(name, col_width)): $(pkginfo.version) ($(pkginfo.source))")
-        else
-            println("$(rpad(name, col_width)): $(pkginfo.version)")
-        end
-    end
-    println("$(rpad("QuantumControl", col_width)): $version")
-end
+include("print_versions.jl")
 
 end

src/print_versions.jl

@@ -0,0 +1,21 @@
+using Pkg
+using UUIDs
+
+"""Print the versions of the packages constituting QuantumControl."""
+function print_versions()
+    project_toml = Pkg.TOML.parsefile(joinpath(@__DIR__, "..", "Project.toml"))
+    version = project_toml["version"]
+    direct_deps = project_toml["deps"]
+    deps = Pkg.dependencies()
+    pkg_names = [name for name in keys(direct_deps) if name ∉ ["Pkg", "UUIDs"]]
+    col_width = maximum([length(name) for name in pkg_names])
+    for name in reverse(pkg_names)
+        pkginfo = deps[UUIDs.UUID(direct_deps[name])]
+        if pkginfo.is_tracking_path
+            println("$(rpad(name, col_width)): $(pkginfo.version) ($(pkginfo.source))")
+        else
+            println("$(rpad(name, col_width)): $(pkginfo.version)")
+        end
+    end
+    println("$(rpad("QuantumControl", col_width)): $version")
+end

src/reexport.jl

@@ -0,0 +1,21 @@
+# I'm aware of Reexport.jl, but it doesn't work for QuantumControl.jl
+#
+# For one thing, `@reexport using QuantumControlBase` re-exports not just the
+# members of `QuantumControlBase`, but also `QuantumControlBase` itself. Also,
+# as far as I can tell `@reexport using QuantumControlBase.Shapes` does not
+# work when it's inside a module also called `Shapes`, as we're doing.
+#
+# Besides, the macro below is pretty trivial
+
+macro reexport_members(modname::Symbol)
+    mod = getfield(__module__, modname)
+    member_names = _exported_names(mod)
+    Expr(:export, member_names...)
+end
+
+function _exported_names(m::Module)
+    return filter!(
+        x -> (Base.isexported(m, x) && (x != nameof(m))),
+        names(m; all=true, imported=true)
+    )
+end