Commit some minor fixes in emit and capture

There are still issues but they will likely require more thought and a
deeper refactoring.

symex-primitives-lisp.el

@@ -168,6 +168,9 @@
 (defvar symex--re-whitespace "[[:space:]|\n]+"
   "Whitespace that may extend over many lines.")
 
+(defvar symex--re-optional-whitespace "[[:space:]|\n]*"
+  "Optional whitespace that may extend over many lines.")
+
 (defvar symex--re-symex-line "^[[:space:]]*[^;[:space:]\n]"
   "A line that isn't blank and isn't a comment line.")
 
@@ -245,7 +248,7 @@
   "Check if we're looking at an empty list."
   (looking-at-p
    (concat symex--re-left
-           symex--re-whitespace
+           symex--re-optional-whitespace
            symex--re-right)))
 
 (defun symex-empty-string-p ()
@@ -258,10 +261,10 @@
 (defun symex-inside-empty-form-p ()
   "Check if point is inside an empty form."
   (and (looking-back (concat symex--re-left
-                             symex--re-whitespace)
+                             symex--re-optional-whitespace)
                      (line-beginning-position))
        (looking-at-p
-        (concat symex--re-whitespace
+        (concat symex--re-optional-whitespace
                 symex--re-right))))
 
 (defun symex--racket-syntax-object-p ()

symex-transformations-lisp.el

@@ -179,12 +179,18 @@ text, on the respective side."
             ((and before
                   (string-match-p (concat symex--re-whitespace "$")
                                   (symex--current-kill)))
+             ;; if the text to be pasted before includes whitespace already,
+             ;; then don't add more
              "")
             (t " ")))))
 
 (defun symex-lisp--paste-before ()
   "Paste before symex."
   (interactive)
+  (when (symex-inside-empty-form-p)
+    (symex--kill-ring-push
+     (string-trim-right
+      (symex--kill-ring-pop))))
   (symex-lisp--paste ""
                      (symex-lisp--padding t)))
 
@@ -217,10 +223,10 @@ If a symex is currently selected, then paste after the end of the
 selected expression. Otherwise, paste in place."
   (interactive)
   (let ((padding (symex-lisp--padding nil)))
-    (if (symex-lisp--point-at-last-symex-p)
-        (symex--kill-ring-push
-         (string-trim-right
-          (symex--kill-ring-pop))))
+    (when (symex-lisp--point-at-last-symex-p)
+      (symex--kill-ring-push
+       (string-trim-right
+        (symex--kill-ring-pop))))
     (save-excursion
       (condition-case nil
           (forward-sexp)