From ddee59e73348acf88bca6e9f32138e4fa322574d Mon Sep 17 00:00:00 2001
From: Olof-Joachim Frahm <olof@macrolet.net>
Date: Wed, 16 Oct 2013 02:05:42 +0200
Subject: [PATCH] Differentiate between T/NIL/undefined/false.

This means that OGET/OSET return the symbol UNDEFINED if a value is undefined
on the Javascript side.  Similarly for FALSE.
---
 src/array.lisp   |    8 ++++++--
 src/ffi.lisp     |   12 ++++++++++++
 src/package.lisp |    5 +++--
 src/prelude.js   |   12 +++++++++++-
 4 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/src/array.lisp b/src/array.lisp
index a15b4eb..1cd4c08 100644
--- a/src/array.lisp
+++ b/src/array.lisp
@@ -54,12 +54,16 @@
     (error "~S is not an array." array))
   (if (eq (oget array "stringp") 1)
       'character
-      (oget array "type")))
+      (let ((type (oget array "type")))
+        (and (not (undefined type))
+             type))))
 
 (defun array-dimensions (array)
   (unless (arrayp array)
     (error "~S is not an array." array))
-  (oget array "dimensions"))
+  (let ((dimensions (oget array "dimensions")))
+    (and (not (undefined dimensions))
+         dimensions)))
 
 ;; TODO: Error checking
 (defun array-dimension (array axis)
diff --git a/src/ffi.lisp b/src/ffi.lisp
index db6a23e..d833d96 100644
--- a/src/ffi.lisp
+++ b/src/ffi.lisp
@@ -15,6 +15,18 @@
 
 (/debug "loading ffi.lisp!")
 
+;; for FFI
+(defconstant false 'false)
+(%js-vset "falseSymbol" false)
+(defconstant undefined 'undefined)
+(%js-vset "undefinedSymbol" undefined)
+
+(defun false (x)
+  (eq x false))
+
+(defun undefined (x)
+  (eq x undefined))
+
 (define-setf-expander oget (object key &rest keys)
   (let* ((keys (cons key keys))
          (g!object (gensym))
diff --git a/src/package.lisp b/src/package.lisp
index 3ee5105..b026cd4 100644
--- a/src/package.lisp
+++ b/src/package.lisp
@@ -122,7 +122,6 @@
       (if foundp
           (values symbol foundp)
           (let ((symbols (%package-symbols package)))
-            (oget symbols name)
             (let ((symbol (make-symbol name)))
               (setf (oget symbol "package") package)
               (when (eq package *keyword-package*)
@@ -136,7 +135,9 @@
 (defun symbol-package (symbol)
   (unless (symbolp symbol)
     (error "`~S' is not a symbol." symbol))
-  (oget symbol "package"))
+  (let ((package (oget symbol "package")))
+    (and (not (undefined package))
+         package)))
 
 (defun export (symbols &optional (package *package*))
   (let ((exports (%package-external-symbols package)))
diff --git a/src/prelude.js b/src/prelude.js
index f3ef952..25908d5 100644
--- a/src/prelude.js
+++ b/src/prelude.js
@@ -4,6 +4,8 @@
 var window = this;
 var t;
 var nil;
+var falseSymbol;
+var undefinedSymbol;
 
 var lisp = {};
 
@@ -119,6 +121,10 @@ function lisp_to_js (x) {
         return null;
     else if (x === t)
         return true;
+    else if (x === falseSymbol)
+        return false;
+    else if (x === undefinedSymbol)
+        return undefined;
     else if (typeof x == 'object' && 'length' in x && x.stringp == 1)
         return xstring(x);
     else if (typeof x == 'function'){
@@ -134,10 +140,14 @@ function lisp_to_js (x) {
 }
 
 function js_to_lisp (x) {
-    if (x === null || x === undefined || x === false)
+    if (x === null)
         return nil;
     else if (x === true)
         return t;
+    else if (x === false)
+        return falseSymbol;
+    else if (x === undefined)
+        return undefinedSymbol;
     else if (typeof x == 'string')
         return make_lisp_string(x);
     else if (typeof x == 'function'){
-- 
1.7.10.4