From 85ac96e3e2de4a3598c1658f7c1de6cf88734d93 Mon Sep 17 00:00:00 2001
From: David Nolen <david.nolen@gmail.com>
Date: Tue, 29 Oct 2013 18:45:28 -0400
Subject: [PATCH] CLJS-646: single segment namespaces and reify don't work

the exists? call in reify was not correct, it was a property access on
the namespace, which would of course get resolved by the compiler,
creating a symbol foo/foo (in the case where foo is the single segment
namespace). now we actually emit a symbol of the namespace and the type
symbol, the exists? macro now annotates this symbol with
:cljs.analyzer/no-resolve, the analyzer now respects this so the user
won't get spurious warnings from using exists? on vars that don't exist.
---
 src/clj/cljs/analyzer.clj | 4 +++-
 src/clj/cljs/core.clj     | 7 +++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/clj/cljs/analyzer.clj b/src/clj/cljs/analyzer.clj
index 0b9920e494..4d3cb6ff18 100644
--- a/src/clj/cljs/analyzer.clj
+++ b/src/clj/cljs/analyzer.clj
@@ -247,7 +247,9 @@
                      :ns full-ns})))))))
 
 (defn resolve-existing-var [env sym]
-  (resolve-var env sym confirm-var-exists))
+  (if-not (-> sym meta ::no-resolve)
+    (resolve-var env sym confirm-var-exists)
+    (resolve-var env sym)))
 
 (defn confirm-bindings [env names]
   (doseq [name names]
diff --git a/src/clj/cljs/core.clj b/src/clj/cljs/core.clj
index 87149eba77..1e76b4d7a2 100644
--- a/src/clj/cljs/core.clj
+++ b/src/clj/cljs/core.clj
@@ -279,8 +279,11 @@
 (defmacro string? [x]
   (bool-expr (list 'js* "typeof ~{} === 'string'" x)))
 
+;; TODO: x must be a symbol, not an arbitrary expression
 (defmacro exists? [x]
-  (bool-expr (list 'js* "typeof ~{} !== 'undefined'" x)))
+  (bool-expr
+    (list 'js* "typeof ~{} !== 'undefined'"
+      (vary-meta x assoc :cljs.analyzer/no-resolve true))))
 
 (defmacro undefined? [x]
   (bool-expr (list 'js* "(void 0 === ~{})" x)))
@@ -576,7 +579,7 @@
         ns     (-> &env :ns :name)
         munge  cljs.compiler/munge]
     `(do
-       (when-not (exists? (. ~ns ~(symbol (core/str "-" t))))
+       (when-not (exists? ~(symbol (core/str ns) (core/str t)))
          (deftype ~t [~@locals ~meta-sym]
            IWithMeta
            (~'-with-meta [~this-sym ~meta-sym]