Add support for facts.

modules/ordo.scm

@@ -2,6 +2,7 @@
   #:use-module (ice-9 exceptions)
   #:use-module (logging logger)
   #:use-module (ordo connection)
+  #:use-module (ordo facts)
   #:use-module (srfi srfi-1)  ; list utils
   #:use-module (srfi srfi-9)  ; records
   #:use-module (srfi srfi-26) ; cut
@@ -27,6 +28,7 @@
             playbook-plays
             run-playbook
             $
+            $$
             register-play-var
             register-playbook-var))
 
@@ -67,6 +69,10 @@ variable (in that order). Raise an exception if the variable is not found."
                  v)))))
   (lookup-var var-name (list +play-vars+ +playbook-vars+)))
 
+(define ($$ . keys)
+  "Look up nested keys in gathered facts."
+  (apply get-fact (hash-table-ref +play-vars+ #:ordo-facts) keys))
+
 (define +triggers+ #f)
 
 (define (add-triggers triggers)
@@ -106,18 +112,19 @@ variable (in that order). Raise an exception if the variable is not found."
   (make-handler name action))
 
 (define-record-type <play>
-  (make-play name connection vars tasks handlers)
+  (make-play name connection vars gather-facts tasks handlers)
   play?
   (name play-name)
   (connection play-connection)
   (vars play-vars)
   (tasks play-tasks)
-  (handlers play-handlers))
+  (handlers play-handlers)
+  (gather-facts play-gather-facts))
 
-(define* (play name #:key connection (vars '()) . more)
+(define* (play name #:key connection (vars '()) (gather-facts #t) . more)
   (let ((tasks (filter task? more))
         (handlers (filter handler? more)))
-    (make-play name connection vars tasks handlers)))
+    (make-play name connection vars gather-facts tasks handlers)))
 
 (define (run-play p)
   (log-msg 'NOTICE "Running play " (play-name p))
@@ -126,6 +133,8 @@ variable (in that order). Raise an exception if the variable is not found."
       (set! +play-vars+ (alist->hash-table (play-vars p) equal?))
       (init-connection! (play-connection p)))
     (lambda ()
+      (when (play-gather-facts p)
+        (hash-table-set! +play-vars+ #:ordo-facts (gather-facts (play-connection p))))
       (for-each (cut run-task <> (play-connection p)) (play-tasks p))
       (for-each (lambda (h)
                   (when (member (handler-name h) +triggers+)