X-Git-Url: https://git.hcoop.net/clinton/parenscript.git/blobdiff_plain/1af04ae56277989d39b46f5924c8f8a90bf4c6e0..c72e87d8951cdb4bf9315c2dfae99b99d91a3a60:/src/lib/js-utils.lisp

diff --git a/src/lib/js-utils.lisp b/src/lib/js-utils.lisp
index 5644972..5e413bd 100644
--- a/src/lib/js-utils.lisp
+++ b/src/lib/js-utils.lisp
@@ -37,7 +37,24 @@
 (defpsmacro ignore-errors (&body body)
   `(try (progn ,@body) (:catch (e))))
 
+;;; Data structures
+
+(defpsmacro length (a)
+  `(.size ,a))
+
 ;;; Misc
 
 (defpsmacro null (x)
   `(= ,x nil))
+
+(defpsmacro @ (obj &rest props)
+  "Handy slot-value/aref composition macro."
+  (if (null props)
+      obj
+      `(@ (slot-value
+           ,(if (stringp obj) `($ ,obj) obj)
+           ,(let ((prop (macroexpand (first props))))
+                 (if (symbolp prop)
+                     `',prop
+                     prop)))
+        ,@(cdr props))))
\ No newline at end of file