branch: elpa/llama
commit 67a43eb4f0502d92227b9513eb247355aa5e598e
Author: Jonas Bernoulli <jo...@bernoul.li>
Commit: Jonas Bernoulli <jo...@bernoul.li>
Support explicit unused arguments
- Support trailing unused (mandatory and/or optional) arguments.
- Support unused optional arguments, in between (used and/or unused)
mandatory arguments and used optional arguments. (In a later step
we will start preferring optional arguments, for unused arguments
that are not explicitly named.)
---
llama.el | 72 ++++++++++++++++++++++++++++++++++++++++++++++------------------
1 file changed, 52 insertions(+), 20 deletions(-)
diff --git a/llama.el b/llama.el
index 33dff5b2e3..a1fc5fd086 100644
--- a/llama.el
+++ b/llama.el
@@ -105,26 +105,24 @@ omitting the whitespace between it and the following
symbol.
It also looks a bit like #\\='function."
(unless (symbolp fn)
(signal 'wrong-type-argument (list 'symbolp fn)))
- `(lambda ,(llama--arguments body)
- (,fn ,@body)))
-
-(defun llama--arguments (data)
- (let ((args (make-vector 10 nil))
- (optional nil)
- (pos 0))
- (llama--collect data args)
- (apply #'nconc
+ (let* ((args (make-vector 10 nil))
+ (body (llama--collect body args))
+ (optional nil)
+ (pos 0))
+ `(lambda
+ (,@(apply
+ #'nconc
(mapcar
(lambda (symbol)
(setq pos (1+ pos))
(cond
((not symbol)
(list (intern (format "_%c%s" (if optional ?& ?%) pos))))
- ((eq (aref (symbol-name symbol) 0) ?%)
+ ((string-match-p "\\`_?%" (symbol-name symbol))
(when optional
(error "`%s' cannot follow optional arguments" symbol))
(list symbol))
- ((eq symbol '&*)
+ ((memq symbol '(&* _&*))
(list '&rest symbol))
(optional
(list symbol))
@@ -136,15 +134,19 @@ It also looks a bit like #\\='function."
(push symbol symbols)))
symbols)
(let ((rest (aref args 0)))
- (and rest (list rest))))))))
+ (and rest (list rest)))))))
+ (,fn ,@body))))
+
+(defconst llama--unused-argument (make-symbol "llama--unused-argument"))
(defun llama--collect (expr args)
(cond
((symbolp expr)
(let ((name (symbol-name expr)))
(save-match-data
- (when (string-match "\\`[%&]\\([1-9*]\\)?\\'" name)
- (let* ((pos (match-string 1 name))
+ (cond
+ ((string-match "\\`\\(_\\)?[%&]\\([1-9*]\\)?\\'" name)
+ (let* ((pos (match-string 2 name))
(pos (cond ((equal pos "*") 0)
((not pos) 1)
((string-to-number pos)))))
@@ -152,17 +154,30 @@ It also looks a bit like #\\='function."
(aref args 1)
(not (equal expr (aref args 1))))
(error "`%s' and `%s' are mutually exclusive" expr (aref args
1)))
- (aset args pos expr))))))
- ((memq (car-safe expr) '(## quote)))
+ (aset args pos expr))
+ (if (match-string 1 name)
+ llama--unused-argument
+ expr))
+ (expr)))))
+ ((memq (car-safe expr) '(## quote))
+ expr)
+ ((and (listp expr) (ignore-errors (length expr)))
+ (mapcan (lambda (elt)
+ (let ((symbol (llama--collect elt args)))
+ (and (not (eq symbol llama--unused-argument))
+ (list symbol))))
+ expr))
((listp expr)
(while (consp (cdr expr))
(llama--collect (car expr) args)
(setq expr (cdr expr)))
(when expr
(llama--collect (car expr) args)
- (llama--collect (cdr expr) args)))
+ (llama--collect (cdr expr) args))
+ expr)
((vectorp expr)
- (mapc (lambda (elt) (llama--collect elt args)) expr))))
+ (vconcat (mapcar (lambda (elt) (llama--collect elt args)) expr)))
+ (expr)))
;;; Advices
@@ -231,10 +246,27 @@ It also looks a bit like #\\='function."
(defface llama-optional-argument '((t :inherit font-lock-type-face))
"Face used for optional arguments `&1' through `&9', `&' and `&*'.")
+(defface llama-erased-argument
+ `((((supports :box t))
+ :box ( :line-width ,(if (>= emacs-major-version 28) (cons -1 -1) -1)
+ :style nil
+ :color "red"))
+ (((supports :underline t))
+ :underline "red")
+ (t
+ :inherit font-lock-warning-face))
+ "Face used for erased arguments `_%1'...`_%9', `_&1'...`_&9' and `_&*'.
+This face is used in addition to one of llama's other argument faces.
+Unlike implicit unused arguments (which do not appear in the function
+body), these arguments are erased from the function body during macro
+expansion, and the looks of this face should hint at that.")
+
(defvar llama-font-lock-keywords
'(("(\\(##\\)" 1 'llama-macro)
- ("\\_<\\(?:%[1-9]?\\)\\_>" 0 'llama-mandatory-argument)
- ("\\_<\\(?:&[1-9*]?\\)\\_>" 0 'llama-optional-argument)))
+ ("\\_<\\(?:_?%[1-9]?\\)\\_>" 0 'llama-mandatory-argument)
+ ("\\_<\\(?:_?&[1-9*]?\\)\\_>" 0 'llama-optional-argument)
+ ("\\_<\\(?:_\\(?:%[1-9]?\\|&[1-9*]?\\)\\)\\_>"
+ 0 'llama-erased-argument prepend)))
(defvar llama-fontify-mode-lighter nil)
