emacs: Add Hydra interface.

* emacs/guix-utils.el (guix-hexify, guix-number->bool): New procedures.
  (guix-while-null): New macro.
* emacs/guix-hydra.el: New file.
* emacs/guix-hydra-build.el: New file.
* emacs/guix-hydra-jobset.el: New file.
* emacs.am (ELFILES): Add them.
* doc/emacs.texi (Emacs Hydra): New node.
  (Emacs Interface): Add it.
* doc/guix.texi (Top): Add it.
  (Substitutes): Mention Emacs interface.

1 files changed, 20 insertions, 0 deletions

diff --git a/emacs/guix-utils.el b/emacs/guix-utils.el
index 98a408f875..8c1a5b42de 100644
--- a/emacs/guix-utils.el
+++ b/emacs/guix-utils.el
@@ -174,6 +174,15 @@ add both to the end and to the beginning."
           (t
            (concat separator str separator)))))
 
+(defun guix-hexify (value)
+  "Convert VALUE to string and hexify it."
+  (url-hexify-string (guix-get-string value)))
+
+(defun guix-number->bool (number)
+  "Convert NUMBER to boolean value.
+Return nil, if NUMBER is 0; return t otherwise."
+  (not (zerop number)))
+
 (defun guix-shell-quote-argument (argument)
   "Quote shell command ARGUMENT.
 This function is similar to `shell-quote-argument', but less strict."
@@ -282,6 +291,15 @@ single argument."
      (while (re-search-forward ,regexp nil t)
        ,@body)))
 
+(defmacro guix-while-null (&rest body)
+  "Evaluate BODY until its result becomes non-nil."
+  (declare (indent 0) (debug t))
+  (let ((result-var (make-symbol "result")))
+    `(let (,result-var)
+       (while (null ,result-var)
+         (setq ,result-var ,@body))
+       ,result-var)))
+
 (defun guix-modify (object modifiers)
   "Apply MODIFIERS to OBJECT.
 OBJECT is passed as an argument to the first function from
@@ -527,6 +545,8 @@ See `defun' for the meaning of arguments."
     `((,(rx "(" (group (or "guix-define-reader"
                            "guix-define-readers"
                            "guix-keyword-args-let"
+                           "guix-while-null"
+                           "guix-while-search"
                            "guix-with-indent"))
             symbol-end)
        . 1)