paredit-kill: Tweak rule for adding space if kill-whole-line is t.

For now, disable the yank part of the test -- with kill-whole-line,
killing and then yanking is not always a noop and it's not clear
making it a noop is the right approach.  I don't use kill-whole-line
so I'm not sure what expectations are and I'm reluctant to change it,
except to fix obviously-wrong outcomes like (x|(y)) that should be
(x| (y)).

While here, document the effect of kill-whole-line on paredit-kill.

3 files changed, 27 insertions, 22 deletions

diff --git a/NEWS b/NEWS
index 59659bb..29f9ca8 100644
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,11 @@ https://paredit.org
 Latest release: https://paredit.org/paredit.el
 Current development version: https://paredit.org/paredit-beta.el
 
+** Version 27 (beta)
+
+*** Improved some edge cases in paredit-kill with kill-whole-line enabled.
+**** Many other edge cases are slightly broken; patches welcome!
+
 ** Version 26 -- 2022-11-26
 
 Minor bug fix release, mainly to set a new branch scheme:
diff --git a/paredit.el b/paredit.el
index 8522421..ea14a15 100644
--- a/paredit.el
+++ b/paredit.el
@@ -1509,7 +1509,12 @@ On a line with no S-expressions on it starting after the point or
   within a comment, act exactly as `kill-line'.
 Otherwise, kill all S-expressions that start after the point.
 With a `C-u' prefix argument, just do the standard `kill-line'.
-With a numeric prefix argument N, do `kill-line' that many times."
+With a numeric prefix argument N, do `kill-line' that many times.
+
+If `kill-whole-line' is true, kills the newline character and
+  indentation on the next line as well.
+In that case, ensure there is at least one space between the
+  preceding S-expression and whatever follows on the next line."
   (interactive "P")
   (cond (argument
          (kill-line (if (integerp argument) argument 1)))
@@ -1623,13 +1628,9 @@ With a numeric prefix argument N, do `kill-line' that many times."
         ;; Insert a space to avoid invalid joining if necessary.
         ((let ((syn-before (char-syntax (char-before)))
                (syn-after  (char-syntax (char-after))))
-           (or (and (eq syn-before ?\) )            ; Separate opposing
-                    (eq syn-after  ?\( ))           ;   parentheses,
-               (and (eq syn-before ?\" )            ; string delimiter
-                    (eq syn-after  ?\" ))           ;   pairs,
-               (and (memq syn-before '(?_ ?w))      ; or word or symbol
-                    (memq syn-after  '(?_ ?w)))))   ;   constituents.
-         (insert " "))))
+           (and (memq syn-before '(?\) ?\" ?_ ?w))
+                (memq syn-after '(?\( ?\" ?_ ?w))))
+         (save-excursion (insert " ")))))
 
 ;;;;; Killing Words
 
diff --git a/test.el b/test.el
index 9e1b50c..ca85187 100644
--- a/test.el
+++ b/test.el
@@ -752,13 +752,14 @@ Four arguments: the paredit command, the text of the buffer
     (";f\n(b\n z|)\n" ";f\n(b\n z|)\n")))
 
 (let ((kill-whole-line t))
-  (paredit-test (defun paredit-test-kill ()
+  (paredit-test (defun paredit-test-kill-whole-line ()
                   (interactive)
-                  ;; Horrible kludge.  Do it once, and then yank to make
-                  ;; sure we get back what we expect.  Then do it again,
-                  ;; to get the effects on the buffer the automatic test
-                  ;; framework will check.
-                  (save-excursion
+                  ;; For now the check to see that we yanked the
+                  ;; correct string is disabled, because it isn't quite
+                  ;; right: with kill-whole-line enabled, sometimes it
+                  ;; inserts an extra space to avoid joining two
+                  ;; expressions.
+                  '(save-excursion
                     (let ((kill-ring nil))
                       (let ((text (buffer-string)))
                         (call-interactively 'paredit-kill)
@@ -819,9 +820,8 @@ Four arguments: the paredit command, the text of the buffer
       ("\"\n\"\n|" error)
 
       ("|(a (b) (c)\n   (d) (e))" "|" error)
-      (xfail
-       "(a| (b) (c)\n   (d) (e))"
-       "(a|   (d) (e))"
+      ("(a| (b) (c)\n   (d) (e))"
+       "(a| (d) (e))"
        "(a|)"
        "(a|)")
       (xfail
@@ -885,7 +885,7 @@ Four arguments: the paredit command, the text of the buffer
 
       ("|(a ((b) (c)\n    (d) (e)) (f))" "|" error)
       (xfail "(|a ((b) (c)\n    (d) (e)) (f))" "(| (f))" "(|)" "(|)")
-      (xfail "(a| ((b) (c)\n    (d) (e)) (f))" "(a| (f))" "(a|)" "(a|)")
+      ("(a| ((b) (c)\n    (d) (e)) (f))" "(a| (f))" "(a|)" "(a|)")
       (xfail "(a |((b) (c)\n    (d) (e)) (f))" "(a | (f))" "(a |)" "(a |)")
       (xfail
        "(a (|(b) (c)\n    (d) (e)) (f))"
@@ -968,8 +968,7 @@ Four arguments: the paredit command, the text of the buffer
        "(| (f))"
        "(|)"
        "(|)")
-      (xfail
-       "(a| \"(b) (c)\n )  { ;;;; \n\n\n(d)( (e);\" (f))"
+      ("(a| \"(b) (c)\n )  { ;;;; \n\n\n(d)( (e);\" (f))"
        "(a| (f))"
        "(a|)"
        "(a|)")
@@ -1006,7 +1005,7 @@ Four arguments: the paredit command, the text of the buffer
        "(a \"(b) (c)\n )  { ;;;; \n\n\n|\" (f))")
 
       ("|x(\n)(z)" "|(z)" "|" error)
-      ("x|(\n)(z)" "x|(z)" "x|" error)
+      ("x|(\n)(z)" "x| (z)" "x|" error)
       ("x(|\n)(z)" "x(|)(z)" "x(|)(z)")
       (xfail "x(\n|)(z)" "x(\n|)(z)")
       ("x(\n)|(z)" "x(\n)|" error)
@@ -1015,7 +1014,7 @@ Four arguments: the paredit command, the text of the buffer
       ("x(\n)(z)|" error)
 
       ("|x\"\n\"(z)" "|(z)" "|" error)
-      ("x|\"\n\"(z)" "x|(z)" "x|" error)
+      ("x|\"\n\"(z)" "x| (z)" "x|" error)
       ("x\"|\n\"(z)" "x\"|\"(z)" "x\"|\"(z)")
       ("x\"\n|\"(z)" "x\"\n|\"(z)")
       ("x\"\n\"|(z)" "x\"\n\"|" error)