lens-filesystem

HACKAGE

A lensy style interface to your filesystem.

This is pretty experimental; I wouldn't recommend using it in production code at the moment; Using the read-only operations should be fine, but I'd strongly recommend doing lots of testing with print before you run destructive filesystem operations.

This library is meant to be used in conjunction with the lens-action library.

The interface to this package could change at any time.

Examples:

Many of the combinators you see here come from `lens-action`.

-- Find all files in ~ or ~/config with a .vim or .conf extension
>>> "/Users/chris" ^!! including (path "config") . ls . traversed . exts ["vim", "conf"]
["/Users/chris/.vim","/Users/chris/tmux.conf","/Users/chris/config/plugins.vim"]

-- Check whether a filename is a dotfile
>>> let isDotfile = has (filename . _head . only '.')
-- Crawl a filetree according to a given fold, 
-- e.g. crawl all dirs that aren't dotfiles (a.k.a. .git, .stack-work)
>>> "." ^!! crawling (ls'ed . dirs . filtered (not . isDotfile))
[ "." , "./app" , "./test" , "./src" , "./src/Control"
, "./src/Control/Lens", "./src/Control/Lens/FileSystem"]

-- Crawl ALL files in "src" collecting "*.hs" files, then make file paths absolute
>>> "src" ^!! crawled . exts ["hs"] . absolute
[ "/Users/chris/dev/lens-fs/src/Control/Lens/FileSystem/Combinators.hs"
, "/Users/chris/dev/lens-fs/src/Control/Lens/FileSystem.hs" ]

-- Find all executables in the 'scripts' directory and copy them to bin
>>> "scripts" ^! crawled . withPerms [executable] . act (`copyFile` "/Users/chris/bin")

-- Read all markdown files and get their contents with filename
>>> "./test" ^!! crawled . exts ["md"] . contents . withIndex
[("./test/data/flat/file.md","markdown\n")]

See more examples in the tests