Simple string interpolation.

This allows "%(...)" inside a string literal to interpolate the
stringified result of an expression.

It doesn't support custom interpolators or format strings, but we can
consider extending that later.

test/benchmark/binary_trees.wren

@@ -26,8 +26,8 @@ var stretchDepth = maxDepth + 1
 
 var start = System.clock
 
-System.print("stretch tree of depth " + stretchDepth.toString + " check: " +
-    Tree.new(0, stretchDepth).check.toString)
+System.print("stretch tree of depth %(stretchDepth) check: " +
+    "%(Tree.new(0, stretchDepth).check)")
 
 var longLivedTree = Tree.new(0, maxDepth)
 
@@ -44,12 +44,11 @@ while (depth < stretchDepth) {
     check = check + Tree.new(i, depth).check + Tree.new(-i, depth).check
   }
 
-  System.print((iterations * 2).toString + " trees of depth " +
-      depth.toString + " check: " + check.toString)
+  System.print("%(iterations * 2) trees of depth %(depth) check: %(check)")
   iterations = iterations / 4
   depth = depth + 2
 }
 
-System.print("long lived tree of depth " + maxDepth.toString + " check: " +
-    longLivedTree.check.toString)
-System.print("elapsed: " + (System.clock - start).toString)
+System.print(
+    "long lived tree of depth %(maxDepth) check: %(longLivedTree.check)")
+System.print("elapsed: %(System.clock - start)")

test/benchmark/binary_trees_gc.wren

@@ -26,8 +26,8 @@ var stretchDepth = maxDepth + 1
 
 var start = System.clock
 
-System.print("stretch tree of depth " + stretchDepth.toString + " check: " +
-    Tree.new(0, stretchDepth).check.toString)
+System.print("stretch tree of depth %(stretchDepth) check: " +
+    "%(Tree.new(0, stretchDepth).check)")
 for (i in 1...1000) System.gc()
 
 var longLivedTree = Tree.new(0, maxDepth)
@@ -45,16 +45,15 @@ while (depth < stretchDepth) {
     check = check + Tree.new(i, depth).check + Tree.new(-i, depth).check
   }
 
-  System.print((iterations * 2).toString + " trees of depth " +
-      depth.toString + " check: " + check.toString)
+  System.print("%(iterations * 2) trees of depth %(depth) check: %(check)")
   for (i in 1...1000) System.gc()
 
   iterations = iterations / 4
   depth = depth + 2
 }
 
-System.print("long lived tree of depth " + maxDepth.toString + " check: " +
-    longLivedTree.check.toString)
+System.print(
+    "long lived tree of depth %(maxDepth) check: %(longLivedTree.check)")
 for (i in 1...1000) System.gc()
 
-System.print("elapsed: " + (System.clock - start).toString)
+System.print("elapsed: %(System.clock - start)")

test/benchmark/delta_blue.wren

@@ -696,4 +696,4 @@ for (i in 0...40) {
 }
 
 System.print(total)
-System.print("elapsed: " + (System.clock - start).toString)
+System.print("elapsed: %(System.clock - start)")

test/benchmark/fib.wren

@@ -9,4 +9,4 @@ var start = System.clock
 for (i in 1..5) {
   System.print(Fib.get(28))
 }
-System.print("elapsed: " + (System.clock - start).toString)
+System.print("elapsed: %(System.clock - start)")

test/benchmark/fibers.wren

@@ -13,4 +13,4 @@ for (i in 0...100000) {
 
 fibers[0].call()
 System.print(sum)
-System.print("elapsed: " + (System.clock - start).toString)
+System.print("elapsed: %(System.clock - start)")

test/benchmark/for.wren

@@ -7,4 +7,4 @@ var sum = 0
 for (i in list) sum = sum + i
 
 System.print(sum)
-System.print("elapsed: " + (System.clock - start).toString)
+System.print("elapsed: %(System.clock - start)")

test/benchmark/map_numeric.wren

@@ -16,4 +16,4 @@ for (i in 1..1000000) {
   map.remove(i)
 }
 
-System.print("elapsed: " + (System.clock - start).toString)
+System.print("elapsed: %(System.clock - start)")

test/benchmark/map_string.wren

@@ -97,4 +97,4 @@ for (key in keys) {
 }
 
 System.print(sum)
-System.print("elapsed: " + (System.clock - start).toString)
+System.print("elapsed: %(System.clock - start)")

test/benchmark/method_call.wren

@@ -65,4 +65,4 @@ for (i in 0...n) {
 }
 
 System.print(ntoggle.value)
-System.print("elapsed: " + (System.clock - start).toString)
+System.print("elapsed: %(System.clock - start)")

test/benchmark/string_equals.py

@@ -18,7 +18,7 @@ for i in range(0, 1000000):
     count = count + 1
   if "abc" == "abcd":
     count = count + 1
-  if "changed one character" == "changed %ne character":
+  if "changed one character" == "changed !ne character":
     count = count + 1
   if "123" == 123: count = count + 1
   if "a slightly longer string" == \

test/benchmark/string_equals.wren

@@ -10,7 +10,7 @@ for (i in 1..1000000) {
 
   if ("" == "abc") count = count + 1
   if ("abc" == "abcd") count = count + 1
-  if ("changed one character" == "changed %ne character") count = count + 1
+  if ("changed one character" == "changed !ne character") count = count + 1
   if ("123" == 123) count = count + 1
   if ("a slightly longer string" ==
       "a slightly longer string!") count = count + 1
@@ -21,4 +21,4 @@ for (i in 1..1000000) {
 }
 
 System.print(count)
-System.print("elapsed: " + (System.clock - start).toString)
+System.print("elapsed: %(System.clock - start)")