Range operators!

Added ".." and "..." infix operators. Num implements them to
return Range objects. Those in turn implement the iterator
protocol, so now numeric for loops are easy:

    for (i in 1..10) { ... }

I also cleaned up the Wren benchmarks to use this.

In the process, I discovered the method_call benchmark really
just showed loop peformance, so I unrolled the loops in all of
the languages to stress method calls.

benchmark/README.md

@@ -0,0 +1,19 @@
+The benchmarks in here attempt to faithfully implement the exact same algorithm in a few different languages. We're using Lua, Python, and Ruby for comparison here because those are all in Wren's ballpark: dynamically-typed, object-oriented, bytecode-compiled.
+
+A bit about each benchmark:
+
+## binary_trees
+
+This benchmark stress object creation and garbage collection. It builds a few big, deeply nested binaries and then traverses them.
+
+## fib
+
+This is just a simple naïve Fibonacci number calculator. It was the first benchmark I wrote when Wren supported little more than function calls and arithmetic. It isn't particularly representative of real-world code, but it does stress function call and arithmetic.
+
+## for
+
+This microbenchmark just tests the performance of for loops. Not too useful, but i used it when implementing `for` in Wren to make sure it wasn't too far off the mark.
+
+## method_call
+
+This is the most useful benchmark: it tests dynamic dispatch and polymorphism. You'll note that the main iteration loop is unrolled in all of the implementations. This is to ensure that the loop overhead itself doesn't dwarf the method call time.

benchmark/binary_trees.wren

@@ -33,10 +33,8 @@ var longLivedTree = new Tree(0, maxDepth)
 
 // iterations = 2 ** maxDepth
 var iterations = 1
-var d = 0
-while (d < maxDepth) {
+for (d in 0...maxDepth) {
   iterations = iterations * 2
-  d = d + 1
 }
 
 var depth = minDepth

benchmark/fib.wren

@@ -7,9 +7,7 @@ var fib = fn(n) {
 }
 
 var start = OS.clock
-var i = 0
-while (i < 5) {
+for (i in 1..5) {
   IO.write(fib.call(28))
-  i = i + 1
 }
 IO.write("elapsed: " + (OS.clock - start).toString)

benchmark/for.wren

@@ -1,12 +1,6 @@
 var list = []
 
-{
-  var i = 0
-  while (i < 2000000) {
-    list.add(i)
-    i = i + 1
-  }
-}
+for (i in 0...2000000) list.add(i)
 
 var start = OS.clock
 var sum = 0

benchmark/method_call.lua

@@ -54,12 +54,21 @@ end
 
 function main ()
   local start = os.clock()
-  local N = 1000000
+  local N = 100000
 
   local val = 1
   local toggle = Toggle:new(val)
   for i=1,N do
     val = toggle:activate():value()
+    val = toggle:activate():value()
+    val = toggle:activate():value()
+    val = toggle:activate():value()
+    val = toggle:activate():value()
+    val = toggle:activate():value()
+    val = toggle:activate():value()
+    val = toggle:activate():value()
+    val = toggle:activate():value()
+    val = toggle:activate():value()
   end
   print(val and "true" or "false")
 
@@ -67,6 +76,15 @@ function main ()
   local ntoggle = NthToggle:new(val, 3)
   for i=1,N do
     val = ntoggle:activate():value()
+    val = ntoggle:activate():value()
+    val = ntoggle:activate():value()
+    val = ntoggle:activate():value()
+    val = ntoggle:activate():value()
+    val = ntoggle:activate():value()
+    val = ntoggle:activate():value()
+    val = ntoggle:activate():value()
+    val = ntoggle:activate():value()
+    val = ntoggle:activate():value()
   end
   print(val and "true" or "false")
   io.write(string.format("elapsed: %.8f\n", os.clock() - start))

benchmark/method_call.py

@@ -29,12 +29,21 @@ class NthToggle(Toggle):
 def main():
     start = time.clock()
 
-    NUM = 1000000
+    NUM = 100000
 
     val = 1
     toggle = Toggle(val)
     for i in xrange(0,NUM):
         val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
     if val:
         print "true"
     else:
@@ -44,6 +53,15 @@ def main():
     ntoggle = NthToggle(val, 3)
     for i in xrange(0,NUM):
         val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
     if val:
         print "true"
     else:

benchmark/method_call.rb

@@ -39,12 +39,21 @@ end
 def main()
     start = Time.now
 
-    n = 1000000
+    n = 100000
 
     val = 1
     toggle = Toggle.new(val)
     n.times do
         val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
+        val = toggle.activate().value()
     end
     if val then puts "true" else puts "false" end
 
@@ -52,6 +61,15 @@ def main()
     ntoggle = NthToggle.new(val, 3)
     n.times do
         val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
+        val = ntoggle.activate().value()
     end
     if val then puts "true" else puts "false" end
 

benchmark/method_call.wren

@@ -29,14 +29,21 @@ class NthToggle is Toggle {
 }
 
 var start = OS.clock
-var n = 1000000
-var i = 0
+var n = 100000
 var val = true
 var toggle = new Toggle(val)
 
-while (i < n) {
+for (i in 0...n) {
+  val = toggle.activate.value
+  val = toggle.activate.value
+  val = toggle.activate.value
+  val = toggle.activate.value
+  val = toggle.activate.value
+  val = toggle.activate.value
+  val = toggle.activate.value
+  val = toggle.activate.value
+  val = toggle.activate.value
   val = toggle.activate.value
-  i = i + 1
 }
 
 IO.write(toggle.value)
@@ -44,10 +51,17 @@ IO.write(toggle.value)
 val = true
 var ntoggle = new NthToggle(val, 3)
 
-i = 0
-while (i < n) {
+for (i in 0...n) {
+  val = ntoggle.activate.value
+  val = ntoggle.activate.value
+  val = ntoggle.activate.value
+  val = ntoggle.activate.value
+  val = ntoggle.activate.value
+  val = ntoggle.activate.value
+  val = ntoggle.activate.value
+  val = ntoggle.activate.value
+  val = ntoggle.activate.value
   val = ntoggle.activate.value
-  i = i + 1
 }
 
 IO.write(ntoggle.value)