[parenscript-devel] [PATCH] Implementation of TRY-EXPRESSIONIZE-IF? that doesn't call the printer.

[sblist at me.com]

I needed to avoid secondary calls to the printer for the purpose of 
generating source mappings, but this seems like a more precise
definition anyway (unless I've missed something).

	Scott

---
src/special-operators.lisp |   14 ++++++++++----
1 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/special-operators.lisp b/src/special-operators.lisp
index 3a77ae5..be95a5f 100644
--- a/src/special-operators.lisp
+++ b/src/special-operators.lisp
@@ -130,10 +130,16 @@
    `(ps-js:label ,name ,(wrap-block-for-dynamic-return name (compile-statement `(progn , at body))))))

(defun try-expressionize-if? (form)
-  (< (count #\Newline (with-output-to-string (*psw-stream*)
-                        (let ((*ps-print-pretty* t))
-                          (parenscript-print (compile-statement form) t))))
-     (if (= (length form) 4) 5 4)))
+  (destructuring-bind (if condition
+                          (block . consequent)
+                          &optional
+                          else
+                          alternative-block)
+      (compile-statement form)
+    (declare (ignore if condition else block))
+    (and (= (length consequent) 1)
+         (or (null alternative-block)
+             (= (length alternative-block) 2)))))

(define-statement-operator return-from (tag &optional result)
  (if (not tag)
-- 
1.7.6