CPS and yield: end of life

nuprl · Nov 3, 2017 · f593dfe · f593dfe
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diff --git a/README.md b/README.md
@@ -1,3 +1,19 @@
+Stopify: CPS and Yield End-of-Life
+==================================
+
+This repository has Stopify's CPS and generator based implementations of
+continuations.  We find that they are significantly slower than the approach
+that Stopify now uses. To observe this, run the following script to time CPS
+and generator based continuations:
+
+    yarn install
+    yarn run build
+    ./compare.sh
+
+The script builds and runs `./triangle.js` without ever yielding. You'll find
+that it is 3x (CPS) or 2x (generator) slower than compiling with Stopify
+"jumper"-based strategies.
+
 ## Stopify [![Build Status](http://23.20.114.147:5000/buildStatus/icon?job=stopify-build/master)](http://23.20.114.147:5000/job/stopify-build/job/master/)
 
 Web-based programming environments lack many basic features that programmers

diff --git a/compare.sh b/compare.sh
@@ -0,0 +1,9 @@
+#!/bin/bash
+
+echo "**** CPS ****"
+./bin/stopify --optimize -t cps -i triangle.js > triangle.cps.js
+node --harmony_tailcalls triangle.cps.js
+
+echo "**** Generators ****"
+./bin/stopify --optimize -t yield -i triangle.js > triangle.yield.js
+node --harmony_tailcalls triangle.yield.js
diff --git a/triangle.js b/triangle.js
@@ -0,0 +1,15 @@
+'use strict';
+
+function triangle(n) {
+  if (n === 0) {
+    return 1;
+  }
+  else {
+    return n + triangle(n - 1);
+  }
+}
+
+var r = 0;
+for (var i = 0; i < 150000; i++) {
+  r = (i % 2) + triangle(1000);
+}
diff --git a/yarn.lock b/yarn.lock
@@ -2719,7 +2719,7 @@ ms@2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/ms/-/ms-2.0.0.tgz#5608aeadfc00be6c2901df5f9861788de0d597c8"
 
-nan@>=2.0.0, nan@^2.3.0:
+nan@^2.3.0:
   version "2.6.2"
   resolved "https://registry.yarnpkg.com/nan/-/nan-2.6.2.tgz#e4ff34e6c95fdfb5aecc08de6596f43605a7db45"
 
@@ -3508,12 +3508,6 @@ slash@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/slash/-/slash-1.0.0.tgz#c41f2f6c39fc16d1cd17ad4b5d896114ae470d55"
 
-sleep@3.0.x:
-  version "3.0.1"
-  resolved "https://registry.yarnpkg.com/sleep/-/sleep-3.0.1.tgz#be4d17c579360e07e04ed8172ba2b10a69054df3"
-  dependencies:
-    nan ">=2.0.0"
-
 sntp@1.x.x:
   version "1.0.9"
   resolved "https://registry.yarnpkg.com/sntp/-/sntp-1.0.9.tgz#6541184cc90aeea6c6e7b35e2659082443c66198"