branch: elpa/llama
commit 65b5d9f4469469e99b8b5aab2b671f09c7450d49
Author: Jonas Bernoulli <jo...@bernoul.li>
Commit: Jonas Bernoulli <jo...@bernoul.li>
Hide the empty symbol from completing-read
Re https://github.com/minad/vertico/discussions/481.
---
llama.el | 46 +++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 41 insertions(+), 5 deletions(-)
diff --git a/llama.el b/llama.el
index 1c63a39b60..4f5fdafa8d 100644
--- a/llama.el
+++ b/llama.el
@@ -82,8 +82,8 @@
;;; Code:
;;;###autoload
-(defmacro ## (fn &rest body)
- "Expand to a `lambda' expression that wraps around FN and BODY.
+(defmacro llama (fn &rest body)
+ "Expand to a `lambda' expression that wraps around FN and BODY.
This `lambda' expression calls the function FN with arguments
BODY and returns its value. Its own arguments are derived from
@@ -128,9 +128,10 @@ Note how `_%3' and `_&6' are removed from the body,
because their
names begin with an underscore. Also note that `_&4' is optional,
unlike the explicitly specified `_%3'.
-The name `##' was chosen because that allows (optionally)
-omitting the whitespace between it and the following symbol.
-It also looks a bit like #\\='function."
+The name `##' was chosen because that allows (optionally) omitting
+the whitespace between it and the following symbol. If you dislike
+this trickery, you can alternatively use this macro under the name
+`llama'."
(unless (symbolp fn)
(signal 'wrong-type-argument (list 'symbolp fn)))
(let* ((args (make-vector 10 nil))
@@ -168,6 +169,8 @@ It also looks a bit like #\\='function."
,@(and rest (list '&rest rest)))
(,fn ,@body))))
+(defalias '## 'llama)
+
(defconst llama--unused-argument (make-symbol "llama--unused-argument"))
(defun llama--collect (expr args)
@@ -260,6 +263,39 @@ It also looks a bit like #\\='function."
(advice-add 'elisp-mode-syntax-propertize :override
'llama--elisp-mode-syntax-propertize))
+(defun llama--suspend-empty-symbol-from-collection (fn &rest args)
+ "Unintern the symbol with the empty name during completion.
+
+`##' is the notation for the symbol whose name is the empty string.
+ (intern \"\") => ##
+ (symbol-name \\='##) => \"\"
+
+The `llama' package uses `##' as the name of a macro, which allows
+it to be used akin to syntax, without actually being new syntax.
+(`describe-function' won't let you select `##', but because that is an
+alias for `llama', you can access the documentation under that name.)
+
+This advice prevents the empty string from being offered as a completion
+candidate when `obarray' (or a completion table that internally uses
+that) is used as COLLECTION, by `unintern'ing that symbol temporarily."
+ (let ((plist (symbol-plist '##))
+ (value nil)
+ (bound nil))
+ (with-no-warnings
+ (when (boundp '##)
+ (setq bound t)
+ (setq value ##)))
+ (unwind-protect
+ (progn (unintern "" obarray)
+ (apply fn args))
+ (defalias (intern "") 'llama)
+ (setplist (intern "") plist)
+ (when bound
+ (set (intern "") value)))))
+
+(advice-add 'completing-read :around
+ #'llama--suspend-empty-symbol-from-collection)
+
;;; Fontification
(defgroup llama ()
