Add herbstluftwm configuration with xsession extension

The herbstluftwm configuration isn't complete yet, it's only the package so far,
but it does extend the xsession service to include a line in xsession to execute
the window manager in a bit of a hacky way.

This also adds a ‘mixed-executable-file’ function which is the same as the
‘mixed-text-file’ except that it also sets the executable bit for the computed
file.

oni/home/data/config.scm

@@ -7,6 +7,7 @@
   #:use-module (gnu packages)
   #:use-module (gnu packages admin)
   #:use-module (gnu packages shellutils)
+  #:use-module (gnu packages wm)
   #:use-module (guix gexp)
   #:use-module (oni home services xdisorg)
   #:use-module (oni home services xmodmap)
@@ -14,7 +15,8 @@
   #:use-module (oni home services xsession)
   #:use-module (oni home services compton)
   #:use-module (oni home services xbindkeys)
-  #:use-module (oni home services zsh))
+  #:use-module (oni home services zsh)
+  #:use-module (oni home services herbstluftwm))
 
 (home-environment
  (packages (list (specification->package+output "glibc-locales")))
@@ -218,10 +220,12 @@
             (home-xsession-configuration
              (configuration
               (list
-               "xrdb -cpp m4 -merge \"${HOME}/.config/X11/Xresources\" -I\"${HOME}/.config/X11/Xresources.d\""
-               "xrandr --setprovideroutputsource modesetting NVIDIA-0"
-               "xrandr --auto"
-               "xrandr --dpi 96"))))
+               (mixed-text-file
+                "xsession"
+                "xrdb -cpp m4 -merge \"${HOME}/.config/X11/Xresources\" -I\"${HOME}/.config/X11/Xresources.d\"\n"
+                "xrandr --setprovideroutputsource modesetting NVIDIA-0\n"
+                "xrandr --auto\n"
+                "xrandr --dpi 96\n")))))
 
    (service home-picom-service-type
             (home-picom-configuration
@@ -235,4 +239,6 @@
                                  "class_g = 'trayer'"
                                  "bounding_shaped"))))))
 
-   (service home-xbindkeys-service-type))))
+   (service home-xbindkeys-service-type)
+
+   (service home-herbstluftwm-service-type))))

oni/home/services/herbstluftwm.scm

@@ -0,0 +1,41 @@
+(define-module (oni home services herbstluftwm)
+  #:use-module (gnu services configuration)
+  #:use-module (gnu packages wm)
+  #:use-module (gnu home services)
+  #:use-module (gnu home services utils)
+  #:use-module (guix packages)
+  #:use-module (guix gexp)
+  #:use-module (oni home services xsession)
+
+  #:export (home-herbstluftwm-service-type
+            home-herbstluftwm-configuration))
+
+(define-configuration/no-serialization home-herbstluftwm-configuration
+  (package
+   (package herbstluftwm)
+   "Package use for setting herbstluftwm"))
+
+(define (add-herbstluftwm-packages config)
+  (list (home-herbstluftwm-configuration-package config)))
+
+(define (add-herbstluftwm-executable config)
+  (home-xsession-extension
+   (wm
+    (list
+     (mixed-text-file
+      "xsession"
+      "exec " herbstluftwm "/bin/herbstluftwm")))))
+
+(define home-herbstluftwm-service-type
+  (service-type
+   (name 'home-herbstluftwm)
+   (extensions
+    (list (service-extension
+           home-profile-service-type
+           add-herbstluftwm-packages)
+          (service-extension
+           home-xsession-service-type
+           add-herbstluftwm-executable)))
+   (compose identity)
+   (default-value (home-herbstluftwm-configuration))
+   (description "Install and configure herbstluftwm.")))

oni/home/services/xsession.scm

@@ -4,20 +4,52 @@
   #:use-module (gnu home services utils)
   #:use-module (guix packages)
   #:use-module (guix gexp)
+  #:use-module (srfi srfi-1)
 
   #:export (home-xsession-service-type
-            home-xsession-configuration))
+            home-xsession-configuration
+            home-xsession-extension))
 
-(define-configuration/no-serialization home-xsession-configuration
+(define-configuration home-xsession-configuration
   (configuration
    (text-config '())
    "Configuration"))
 
+(define-configuration/no-serialization home-xsession-extension
+  (wm
+   (text-config '())
+   "String"))
+
+(define* (mixed-executable-file name #:key guile #:rest text)
+  "Return an object representing store file NAME containing TEXT.  TEXT is a
+sequence of strings and file-like objects, as in:
+
+  (mixed-text-file \"profile\"
+                   \"export PATH=\" coreutils \"/bin:\" grep \"/bin\")
+
+This is the declarative counterpart of 'text-file*'."
+  (define build
+    (let ((text (if guile (drop text 2) text)))
+      (gexp (call-with-output-file (ungexp output "out")
+              (lambda (port)
+                (set-port-encoding! port "UTF-8")
+                (display (string-append (ungexp-splicing text)) port)
+                (chmod port #o555))))))
+
+  (computed-file name build #:guile guile))
+
 (define (xsession-home-files config)
-  `(("xsession"
-     ,(mixed-text-file
+  `((".xsession"
+     ,(mixed-executable-file
        "xsession"
-       (string-join (home-xsession-configuration-configuration config) "\n")))))
+       (serialize-text-config 'configuration (home-xsession-configuration-configuration config))))))
+
+(define (home-xsession-extensions original-config extension-configs)
+  (home-xsession-configuration
+   (inherit original-config)
+   (configuration
+    (append (home-xsession-configuration-configuration original-config)
+            (home-xsession-extension-wm (last extension-configs))))))
 
 (define home-xsession-service-type
   (service-type
@@ -27,5 +59,6 @@
            home-files-service-type
            xsession-home-files)))
    (compose identity)
+   (extend home-xsession-extensions)
    (default-value (home-xsession-configuration))
    (description "Configure xsession.")))