Readme for filepath-1.3.0.2
System.FilePath
I have written a System.FilePath
module in part based on the one in
Yhc, and in part based on the one in Cabal (thanks to Lemmih). The aim
is to try and get this module into the base package, as FilePath
s
are something many programs use, but its all too easy to hack up a
little function that gets it right most of the time on most platforms,
and there lies a source of bugs.
This module is Posix (Linux) and Windows capable - just import
System.FilePath
and it will pick the right one. Of course, if you
demand Windows paths on all OSes, then System.FilePath.Windows
will
give you that (same with Posix). Written in Haskell 98 with
Hierarchical Modules.
If you go to the Haddock page, there are a few little examples at the top of the re-exported module.
Acknowledgments
Thanks to Marc Webber, shapr, David House, Lemmih, others...
Competitors
System.FilePath
from Cabal, by Lemmih FilePath.hs
and
NameManip.hs
from MissingH
The one from Cabal and FilePath.hs
in MissingH are both very
similar, I stole lots of good ideas from those two.
NameManip.hs
seems to be more unix specific, but all functions in
that module have equivalents in this new System.FilePath
module.
Hopefully this new module can be used without noticing any lost functions, and certainly adds new features/functions to the table.
Should FilePath
be an abstract data type?
The answer for this library is no. This is a deliberate design decision.
In Haskell 98 the definition is type FilePath = String
, and all
functions operating on FilePath
s, i.e. readFile
/writeFile
etc
take FilePath
s. The only way to introduce an abstract type is to
provide wrappers for these functions or casts between String
s and
FilePathAbstract
s.
There are also additional questions as to what constitutes a
FilePath
, and what is just a pure String
. For example,
"/path/file.ext" is a FilePath
. Is "/" ? "/path" ? "path" ?
"file.ext" ? ".ext" ? "file" ?
With that being accepted, it should be trivial to write
System.FilePath.ByteString
which has the same interface as
System.FilePath
yet operates on ByteString
s.