1 files changed, 33 insertions, 0 deletions

diff --git a/modules/ryan-config/utils.scm b/modules/ryan-config/utils.scm
new file mode 100644
index 0000000..e889e69
--- /dev/null
+++ b/modules/ryan-config/utils.scm
@@ -0,0 +1,33 @@
+(define-module (ryan-config utils)
+  #:use-module (gnu packages)
+  #:use-module (gnu services)
+  #:use-module (gnu home services)
+  #:use-module (gnu home services shepherd)
+  #:use-module (gnu packages freedesktop)
+  #:use-module (gnu services configuration)
+  #:use-module (guix gexp)
+  #:use-module (ice-9 regex)
+  #:use-module (ice-9 pretty-print)
+  #:use-module (ice-9 textual-ports)
+
+  #:export (gather-manifest-packages
+            apply-template-file))
+
+(define (apply-template template-string value-alist)
+  (regexp-substitute/global #f
+                            "\\$\\{([A-Za-z/\\-]+)\\}"
+                            template-string
+                            'pre
+                            (lambda (m)
+                              (let ((entry (assq (string->symbol (match:substring m 1))
+                                                 value-alist)))
+                                (if entry
+                                    (cdr entry)
+                                    "VALUE NOT FOUND")))
+                            'post))
+
+(define (apply-template-file file-path value-alist)
+  (call-with-input-file file-path
+    (lambda (port)
+      (apply-template (get-string-all port)
+                      value-alist))))