diff options
Diffstat (limited to 'guix/gexp.scm')
| -rw-r--r-- | guix/gexp.scm | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/guix/gexp.scm b/guix/gexp.scm index 2622c5cb62..b9525603ee 100644 --- a/guix/gexp.scm +++ b/guix/gexp.scm @@ -78,6 +78,8 @@ gexp->script text-file* mixed-text-file + file-union + directory-union imported-files imported-modules compiled-modules @@ -1171,6 +1173,56 @@ This is the declarative counterpart of 'text-file*'." (computed-file name build)) +(define (file-union name files) + "Return a <computed-file> that builds a directory containing all of FILES. +Each item in FILES must be a two-element list where the first element is the +file name to use in the new directory, and the second element is a gexp +denoting the target file. Here's an example: + + (file-union \"etc\" + `((\"hosts\" ,(plain-file \"hosts\" + \"127.0.0.1 localhost\")) + (\"bashrc\" ,(plain-file \"bashrc\" + \"alias ls='ls --color'\")))) + +This yields an 'etc' directory containing these two files." + (computed-file name + (gexp + (begin + (mkdir (ungexp output)) + (chdir (ungexp output)) + (ungexp-splicing + (map (match-lambda + ((target source) + (gexp + (begin + ;; Stat the source to abort early if it does + ;; not exist. + (stat (ungexp source)) + + (symlink (ungexp source) + (ungexp target)))))) + files)))))) + +(define (directory-union name things) + "Return a directory that is the union of THINGS, where THINGS is a list of +file-like objects denoting directories. For example: + + (directory-union \"guile+emacs\" (list guile emacs)) + +yields a directory that is the union of the 'guile' and 'emacs' packages." + (match things + ((one) + ;; Only one thing; return it. + one) + (_ + (computed-file name + (with-imported-modules '((guix build union)) + (gexp (begin + (use-modules (guix build union)) + (union-build (ungexp output) + '(ungexp things))))))))) + ;;; ;;; Syntactic sugar. |