DatasetLoader interface
"""
abstract type DatasetLoader
A `DatasetLoader` defines how a dataset can made available and loaded.
See [`DataDepLoader`](#) as an example.
A `DatasetLoader` has to implement the following functions:
- [`loaddata`](#)
- [`makeavailable`](#)
- [`isavailable`](#)
"""
abstract
type
DatasetLoader
end
function
makeavailable
end
function
isavailable
end
function
loaddata
end
Loader for
DataDeps
"""
struct DataDepLoader(datadep) <: DatasetLoader
A dataset loader that uses DataDeps.jl to load datasets.
The DataDep has to be registered before creating the loader, and will
error otherwise.
"""
struct
DataDepLoader
<:
DatasetLoader
datadep
::
String
function
DataDepLoader
(
datadep
)
if
!
haskey
(
DataDeps
.
registry
,
datadep
)
throw
(
ArgumentError
(
"
DataDep \"
$
datadep
\" does not exist.
"
)
)
end
return
new
(
datadep
)
end
end
function
isavailable
(
loader
::
DataDepLoader
)
!
isnothing
(
DataDeps
.
try_determine_load_path
(
loader
.
datadep
,
@
__FILE__
)
)
end
function
makeavailable
(
loader
::
DataDepLoader
)
return
DataDeps
.
resolve
(
loader
.
datadep
,
@
__FILE__
)
end
function
loaddata
(
loader
::
DataDepLoader
)
isavailable
(
loader
)
||
makeavailable
(
loader
)
return
DataDeps
.
resolve
(
loader
.
datadep
,
@
__FILE__
)
end