tvl-depot/lisp/f/main.lisp
William Carroll 5c9079a410 Splice ./universe directory into ./
Manually merging:
- README.md: I added the description from universe/README.md into the heading of
  dotfiles/README.md.
- .envrc: dotfiles/.envrc was a superset of universe/.envrc
- .gitignore: Adding some of the ignored patterns from universe/.gitignore to
  dotfiles/.gitignore

Everything else here should be a simple rename.
2020-01-29 14:43:20 +00:00

48 lines
1.3 KiB
Common Lisp

(in-package #:cl-user)
(defpackage #:main
(:documentation "Modern API for working with files and directories.")
(:use #:cl)
(:shadow #:type))
(in-package #:main)
;; Common Lisp distinguishes between `namestrings` and `pathnames` as two types
;; of filename representations.
;;
;; A `pathname` is a structured representation of the name of a file, which
;; consists of six parts:
;; 1. host
;; 2. device
;; 3. directory
;; 4. name
;; 5. type
;; 6. version
;; TODO: Should I be using `string` as a type or `namestring`?
(defmacro type (name in out)
`(declaim (ftype (function ,in ,out) ,name)))
(type join (&rest namestring) pathname)
(defun join (&rest args)
"Join ARGS to a single path."
(apply #'merge-pathnames args))
(type ext (pathname) string)
(defun ext (path)
"Return the file extension of PATH."
(pathname-type path))
;; TODO: Define these tests elsewhere.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Tests
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; join
(string= (join "path") "path")
(string= (join "path" "to") "path/to")
(string= (join "/" "path" "to" "heaven") "/path/to/heaven")
;; ext
(string= (ext #p"path/to/file.ext") "ext")
(string= (ext #p"path/to/directory") nil)