From 782d97a3babbd6ae0855ed77a67a49bd87a9859d Mon Sep 17 00:00:00 2001
From: Tony Garnock-Jones <tonyg@leastfixedpoint.com>
Date: Fri, 14 Jun 2019 13:06:40 +0100
Subject: [PATCH] Still whacking away at the singleton issue

---
 packages/core/package.json     |  2 +-
 packages/core/src/dataspace.js | 38 +++++-----------------------------
 2 files changed, 6 insertions(+), 34 deletions(-)

diff --git a/packages/core/package.json b/packages/core/package.json
index c4a4076..2e1d66f 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -23,6 +23,6 @@
   "dependencies": {
     "debug": "^4.1.1",
     "immutable": "^3.8.2",
-    "preserves": "0.0.11"
+    "preserves": "0.0.12"
   }
 }
diff --git a/packages/core/src/dataspace.js b/packages/core/src/dataspace.js
index 227aede..3db893d 100644
--- a/packages/core/src/dataspace.js
+++ b/packages/core/src/dataspace.js
@@ -17,6 +17,11 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 //---------------------------------------------------------------------------
 
+if (require('preserves/src/singletonmodule.js')('syndicate-lang.org/syndicate-js',
+                                                require('../package.json').version,
+                                                'dataspace.js',
+                                                module)) return;
+
 const Immutable = require("immutable");
 const Preserves = require("preserves");
 // const debug = require("debug")("syndicate/core:dataspace");
@@ -37,39 +42,6 @@ const PRIORITY = Object.freeze({
   _count: 6
 });
 
-// Singleton hackery.
-const Dataspace = (function () {
-  const SYNDICATE = Symbol.for('@syndicate-lang/core');
-  const version = require('../package.json').version;
-  if (!(SYNDICATE in global)) {
-    function Dataspace(bootProc) {
-      this.nextId = 0;
-      this.index = new Skeleton.Index();
-      this.dataflow = new Dataflow.Graph();
-      this.runnable = Immutable.List();
-      this.pendingActions = Immutable.List([
-        new ActionGroup(null, Immutable.List([new Spawn(null, bootProc, Immutable.Set())]))]);
-      this.activatedModules = Immutable.Set();
-      this.actors = Immutable.Map();
-    }
-
-    // Parameters
-    Dataspace._currentFacet = null;
-    Dataspace._inScript = true;
-
-    global[SYNDICATE] = {
-      version: version,
-      Dataspace: Dataspace,
-    };
-  }
-  const g = global[SYNDICATE];
-  if (g.version !== version) {
-    console.warn('Potentially incompatible versions of @syndicate-lang/core loaded:',
-                 version, g.version);
-  }
-  return g.Dataspace;
-})();
-
 Dataspace.BootSteps = Symbol.for('SyndicateBootSteps');
 
 Dataspace.currentFacet = function () {