Move search path specifications to (guix search-paths).

* guix/packages.scm (<search-path-specification>,
  search-path-specification->sexp, sexp->search-path-specification):
  Move to...
* guix/search-paths.scm: ... here.  New file.
* Makefile.am (MODULES): Add it.
* guix/build-system/cmake.scm, guix/build-system/glib-or-gtk.scm,
  guix/build-system/gnu.scm, guix/build-system/haskell.scm,
  guix/build-system/perl.scm, guix/build-system/python.scm,
  guix/build-system/ruby.scm, guix/build-system/waf.scm,
  guix/profiles.scm, guix/scripts/package.scm: Use it.

1 files changed, 77 insertions, 0 deletions

diff --git a/guix/search-paths.scm b/guix/search-paths.scm
new file mode 100644
index 0000000000..147bfcae8c
--- /dev/null
+++ b/guix/search-paths.scm
@@ -0,0 +1,77 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix search-paths)
+  #:use-module (guix records)
+  #:use-module (ice-9 match)
+  #:export (<search-path-specification>
+            search-path-specification
+            search-path-specification?
+            search-path-specification-variable
+            search-path-specification-files
+            search-path-specification-separator
+            search-path-specification-file-type
+            search-path-specification-file-pattern
+
+            search-path-specification->sexp
+            sexp->search-path-specification))
+
+;;; Commentary:
+;;;
+;;; This module defines "search path specifications", which allow packages to
+;;; declare environment variables that they use to define search paths.  For
+;;; instance, GCC has the 'CPATH' variable, Guile has the 'GUILE_LOAD_PATH'
+;;; variable, etc.
+;;;
+;;; Code:
+
+;; The specification of a search path.
+(define-record-type* <search-path-specification>
+  search-path-specification make-search-path-specification
+  search-path-specification?
+  (variable     search-path-specification-variable) ;string
+  (files        search-path-specification-files)    ;list of strings
+  (separator    search-path-specification-separator ;string
+                (default ":"))
+  (file-type    search-path-specification-file-type ;symbol
+                (default 'directory))
+  (file-pattern search-path-specification-file-pattern ;#f | string
+                (default #f)))
+
+(define (search-path-specification->sexp spec)
+  "Return an sexp representing SPEC, a <search-path-specification>.  The sexp
+corresponds to the arguments expected by `set-path-environment-variable'."
+  ;; Note that this sexp format is used both by build systems and in
+  ;; (guix profiles), so think twice before you change it.
+  (match spec
+    (($ <search-path-specification> variable files separator type pattern)
+     `(,variable ,files ,separator ,type ,pattern))))
+
+(define (sexp->search-path-specification sexp)
+  "Convert SEXP, which is as returned by 'search-path-specification->sexp', to
+a <search-path-specification> object."
+  (match sexp
+    ((variable files separator type pattern)
+     (search-path-specification
+      (variable variable)
+      (files files)
+      (separator separator)
+      (file-type type)
+      (file-pattern pattern)))))
+
+;;; search-paths.scm ends here