@syndicate-lang/driver-timer

Makefile

@@ -1,4 +1,4 @@
-MAKEABLE_PACKAGES=syntax syntax-playground
+MAKEABLE_PACKAGES=syntax driver-timer syntax-playground
 
 all:
 	for p in $(MAKEABLE_PACKAGES); do $(MAKE) -C packages/$$p; done

packages/driver-timer/.babelrc

@@ -0,0 +1,4 @@
+{
+  "presets": [ "@babel/preset-env" ],
+  "plugins": [ "@syndicate-lang/syntax/plugin" ]
+}

packages/driver-timer/Makefile

@@ -0,0 +1,8 @@
+.PHONY: build
+
+build:
+	mkdir -p lib
+	npx syndicate-babel src --out-dir lib
+
+clean:
+	rm -rf lib

packages/driver-timer/package.json

@@ -0,0 +1,18 @@
+{
+  "name": "@syndicate-lang/driver-timer",
+  "version": "0.0.0",
+  "description": "Time and timer driver for Syndicate/js",
+  "main": "lib/index.js",
+  "repository": "github:syndicate-lang/syndicate-js",
+  "author": "Tony Garnock-Jones <tonyg@leastfixedpoint.com>",
+  "license": "GPL-3.0+",
+  "homepage": "https://github.com/syndicate-lang/syndicate-js/tree/master/packages/driver-timer",
+  "devDependencies": {
+    "@babel/core": "^7.1.2",
+    "@babel/preset-env": "^7.1.0",
+    "@syndicate-lang/syntax": "^0.0.7"
+  },
+  "dependencies": {
+    "@syndicate-lang/core": "^0.0.5"
+  }
+}

packages/driver-timer/src/index.js

@@ -0,0 +1,77 @@
+//---------------------------------------------------------------------------
+// @syndicate-lang/syntax-test, a demo of Syndicate extensions to JS.
+// Copyright (C) 2016-2018 Tony Garnock-Jones <tonyg@leastfixedpoint.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//---------------------------------------------------------------------------
+
+import { Observe, Dataspace } from "@syndicate-lang/core";
+
+export { PeriodicTick, TimeLaterThan };
+
+message type PeriodicTick(intervalMS);
+assertion type TimeLaterThan(deadlineMS);
+
+spawn named 'driver-timer/PeriodicTick' {
+  during Observe(PeriodicTick($intervalMS)) spawn named ('PeriodicTick('+intervalMS+')') {
+    let handle = null;
+    let finish = Dataspace.backgroundTask();
+    on start {
+      handle = setInterval(Dataspace.wrapExternal(() => {
+        << PeriodicTick(intervalMS);
+      }, intervalMS));
+    }
+    on stop {
+      if (handle) {
+        clearInterval(handle);
+        handle = null;
+      }
+      if (finish) {
+        finish();
+        finish = null;
+      }
+    }
+  }
+}
+
+spawn named 'driver-timer/TimeLaterThan' {
+  during Observe(TimeLaterThan($deadlineMS)) spawn named ('TimeLaterThan('+deadlineMS+')') {
+    let handle = null;
+    let finish = Dataspace.backgroundTask();
+    on start {
+      let delta = deadlineMS - (+(new Date()));
+      console.log('Observation of TimeLaterThan', deadlineMS, delta);
+      handle = setTimeout(Dataspace.wrapExternal(() => {
+        console.log('Firing TimeLaterThan', deadlineMS);
+        handle = null;
+        finish();
+        finish = null;
+        react {
+          assert TimeLaterThan(deadlineMS);
+        }
+      }, delta));
+    }
+    on stop {
+      console.log('Retraction of observation of TimeLaterThan', deadlineMS);
+      if (handle) {
+        clearTimeout(handle);
+        handle = null;
+      }
+      if (finish) {
+        finish();
+        finish = null;
+      }
+    }
+  }
+}

packages/syntax-playground/package.json

@@ -13,6 +13,7 @@
   },
   "dependencies": {
     "@syndicate-lang/core": "^0.0.5",
+    "@syndicate-lang/driver-timer": "^0.0.0",
     "webpack": "^4.23.1",
     "webpack-cli": "^3.1.2"
   }

packages/syntax-playground/src/ticker.js

@@ -18,29 +18,22 @@
 
 import { Dataspace } from "@syndicate-lang/core";
 
-message type Tick();
+const Timer = activate require("@syndicate-lang/driver-timer");
+const TimeLaterThan = Timer.TimeLaterThan;
 
 spawn named 'ticker' {
   field this.counter = 0;
+  field this.deadline = +(new Date());
 
   on start { console.log('ticker starting'); }
   on stop  { console.log('ticker stopping'); }
 
-  on message Tick() {
+  on asserted TimeLaterThan(this.deadline) {
     this.counter++;
     console.log('tick', new Date(), this.counter);
-    if (this.counter < 5) {
-      Dataspace.backgroundTask((finish) => {
-        setTimeout(Dataspace.wrapExternal(() => {
-          << Tick();
-          finish();
-        }), 1000);
-      });
-    }
+    this.deadline += 1000;
   }
 
-  on start {
-    console.log('sending first tick');
-    << Tick();
-  }
+  stop on (this.counter == 5);
 }
+