> 1. Lose the *...* earmuffs. Elisp doesn't embrace that CL convention for defvars.
I wonder, is it because Emacs had only dynamic binding? Maybe now the "*..*" can be helpful to distinguish dynamic vars from lexical.
> 2. The var's doc should say what it means by "skip". Apparently it means (only) that function `apply-on-rectangle' doesn't apply
its FUNCTION arg to empty lines. I think it's important to say that the var affects (only) that function's behavior.
I think the application of FUNCTION is the main part of `apply-on-rectangle', so it is more or less obvious.
And you can easily see the effect in GUI, when using `rectangle-mark-mode' (C-x SPC).
I'm not quite sure how to name the var.
What it does:
For example you have a buffer "env.sh" with content:
"
FOO=1
BAR=2
"
Now if you do
`M-<' beginning-of-buffer
`C-x SPC' rectangle-mark-mode
`C-n' next-line
`C-n' next-line
`C-t' string-rectangle
`export RET'
With standard rect.el you will get:
"
export FOO=1
export
export BAR=2
"
With patched version and `rectangle-select-skip-line'(new name of var) set to `t':
"
export FOO=1
export BAR=2
"
New version of patch:
--- rect-orig.el 2023-01-31 17:25:08.498658466 +0300
+++ rect-patched.el 2023-02-02 20:21:11.041198925 +0300
@@ -144,11 +144,18 @@
;;; Rectangle operations.
+(defvar rectangle-select-skip-line nil
+ "Control the `apply-on-rectangle' execution.
+`nil' -- apply action to selected lines, `t' -- skip empty lines,
+`function' -- skip line if it return non-`nil'.
+The function get all arguments of `apply-on-rectangle' as input.")
+
(defun apply-on-rectangle (function start end &rest args)
"Call FUNCTION for each line of rectangle with corners at START, END.
FUNCTION is called with two arguments: the start and end columns of the
rectangle, plus ARGS extra arguments. Point is at the beginning of line when
the function is called.
+The `rectangle-select-skip-line' variable allow to skip lines.
The final point after the last operation will be returned."
(save-excursion
(let* ((cols (rectangle--pos-cols start end))
@@ -166,7 +173,14 @@
(goto-char startpt)
(while
(progn
- (apply function startcol endcol args)
+ (when (cond
+ ((null rectangle-select-skip-line)
+ t)
+ ((functionp rectangle-select-skip-line)
+ (apply rectangle-select-skip-line function start end args))
+ (t
+ (not (string-match-p "\\`\\s-*$" (thing-at-point 'line)))))
+ (apply function startcol endcol args))
(setq final-point (point))
(and (zerop (forward-line 1)) (bolp)
(<= (point) endpt))))