From b9bbf3a15fd9162fecef160c5c32d1628014671b Mon Sep 17 00:00:00 2001
From: Expanding Man <savastio@protonmail.com>
Date: Tue, 25 Jan 2022 18:37:42 -0500
Subject: [PATCH] experimental traits to more cleanly extend to key-value
 stores

---
 src/FilePathsBase.jl | 13 +++++++++++++
 src/path.jl          |  7 ++++++-
 src/system.jl        |  2 ++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/FilePathsBase.jl b/src/FilePathsBase.jl
index d3b35d1..21d15a1 100644
--- a/src/FilePathsBase.jl
+++ b/src/FilePathsBase.jl
@@ -100,6 +100,19 @@ Defines an abstract filesystem path.
 """
 abstract type AbstractPath end  # Define the AbstractPath here to avoid circular include dependencies
 
+# whether path is a key-value store or true file system
+abstract type DirectoriesType end
+struct DirectoriesExplicit <: DirectoriesType end
+struct DirectoriesImplicit <: DirectoriesType end
+
+# whether path supports permissions
+abstract type PermissionsType end
+struct HasPermissions <: PermissionsType end
+struct NoPermissions <: PermissionsType end
+
+directoriestype(::Type{<:AbstractPath}) = DirectoriesExplicit()
+permissionstype(::Type{<:AbstractPath}) = NoPermissions()
+
 """
     register(::Type{<:AbstractPath})
 
diff --git a/src/path.jl b/src/path.jl
index 62f8e8d..3c56394 100644
--- a/src/path.jl
+++ b/src/path.jl
@@ -533,8 +533,13 @@ julia> created(p"src/FilePathsBase.jl")
 ```
 """
 created(fp::AbstractPath) = stat(fp).ctime
-Base.isdir(fp::AbstractPath) = isdir(mode(fp))
+
+Base.isdir(fp::AbstractPath) = isdir(directoriestype(fp), fp)
+Base.isdir(::DirectoriesExplicit, fp::AbstractPath) = isdir(mode(fp))
+
 Base.isfile(fp::AbstractPath) = isfile(mode(fp))
+
+#TODO: most of these clearly only make sense on local FS, should they have traits?
 Base.islink(fp::AbstractPath) = islink(lstat(fp).mode)
 Base.issocket(fp::AbstractPath) = issocket(mode(fp))
 Base.isfifo(fp::AbstractPath) = issocket(mode(fp))
diff --git a/src/system.jl b/src/system.jl
index ffc38d9..5dc2658 100644
--- a/src/system.jl
+++ b/src/system.jl
@@ -6,6 +6,8 @@ methods that wrap base functionality.
 """
 abstract type SystemPath <: AbstractPath end
 
+permissionstype(::Type{<:SystemPath}) = HasPermissions()
+
 Path() = @static Sys.isunix() ? PosixPath() : WindowsPath()
 Path(pieces::Tuple{Vararg{String}}) =
     @static Sys.isunix() ? PosixPath(pieces) : WindowsPath(pieces)