Make IO a static class instead of a singleton.

benchmark/binary_trees.wren

@@ -26,7 +26,7 @@ var stretchDepth = maxDepth + 1
 
 var start = OS.clock
 
-io.write("stretch tree of depth " + stretchDepth.toString + " check: " +
+IO.write("stretch tree of depth " + stretchDepth.toString + " check: " +
     new Tree(0, stretchDepth).check.toString)
 
 var longLivedTree = new Tree(0, maxDepth)
@@ -48,13 +48,13 @@ while (depth < stretchDepth) {
     i = i + 1
   }
 
-  io.write((iterations * 2).toString + " trees of depth " + depth.toString +
+  IO.write((iterations * 2).toString + " trees of depth " + depth.toString +
       " check: " + check.toString)
   iterations = iterations / 4
   depth = depth + 2
 }
 
-io.write("long lived tree of depth " + maxDepth.toString + " check: " +
+IO.write("long lived tree of depth " + maxDepth.toString + " check: " +
     longLivedTree.check.toString)
 
-io.write("elapsed: " + (OS.clock - start).toString)
+IO.write("elapsed: " + (OS.clock - start).toString)

benchmark/fib.wren

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

benchmark/method_call.wren

@@ -39,7 +39,7 @@ while (i < n) {
   i = i + 1
 }
 
-io.write(toggle.value)
+IO.write(toggle.value)
 
 val = true
 var ntoggle = new NthToggle(val, 3)
@@ -50,6 +50,6 @@ while (i < n) {
   i = i + 1
 }
 
-io.write(ntoggle.value)
+IO.write(ntoggle.value)
 
-io.write("elapsed: " + (OS.clock - start).toString)
+IO.write("elapsed: " + (OS.clock - start).toString)

example/hello.wren

@@ -1 +1 @@
-io.write("Hello, world!")
+IO.write("Hello, world!")

src/wren_core.c

@@ -436,6 +436,7 @@ DEF_NATIVE(string_subscript)
 
 DEF_NATIVE(io_write)
 {
+  // TODO: Should call toString on its argument.
   wrenPrintValue(args[1]);
   printf("\n");
   return args[1];
@@ -531,12 +532,7 @@ void wrenInitializeCore(WrenVM* vm)
   NATIVE(vm->stringClass, "[ ]", string_subscript);
 
   ObjClass* ioClass = defineClass(vm, "IO", vm->objectClass);
-  NATIVE(ioClass, "write ", io_write);
-
-  // TODO: Making this an instance is lame. The only reason we're doing it is
-  // because "IO.write()" looks ugly. Maybe just get used to that?
-  Value ioObject = wrenNewInstance(vm, ioClass);
-  vm->globals[addSymbol(&vm->globalSymbols, "io", 2)] = ioObject;
+  NATIVE(ioClass->metaclass, "write ", io_write);
 
   ObjClass* osClass = defineClass(vm, "OS", vm->objectClass);
   NATIVE(osClass->metaclass, "clock", os_clock);

test/and.wren

@@ -1,26 +1,26 @@
 // Note: These tests implicitly depend on ints being truthy.
-//       Also rely on io.write() returning its argument.
+//       Also rely on IO.write() returning its argument.
 
 // Return the first non-true argument.
-io.write(false && 1) // expect: false
-io.write(true && 1) // expect: 1
-io.write(1 && 2 && false) // expect: false
+IO.write(false && 1) // expect: false
+IO.write(true && 1) // expect: 1
+IO.write(1 && 2 && false) // expect: false
 
 // Return the last argument if all are true.
-io.write(1 && true) // expect: true
-io.write(1 && 2 && 3) // expect: 3
+IO.write(1 && true) // expect: true
+IO.write(1 && 2 && 3) // expect: 3
 
 // Short-circuit at the first false argument.
-io.write(true) && // expect: true
-    io.write(false) && // expect: false
-    io.write(false) // should not print
+IO.write(true) && // expect: true
+    IO.write(false) && // expect: false
+    IO.write(false) // should not print
 
 // Swallow a trailing newline.
-io.write(true &&
+IO.write(true &&
     true) // expect: true
 
 // Only false is falsy.
-io.write(0 && true) // expect: true
-io.write(null && true) // expect: true
-io.write("" && true) // expect: true
-io.write(false && true) // expect: false
+IO.write(0 && true) // expect: true
+IO.write(null && true) // expect: true
+IO.write("" && true) // expect: true
+IO.write(false && true) // expect: false

test/assignment/associativity.wren

@@ -4,6 +4,6 @@ var c = "c"
 
 // Assignment is right-associative.
 a = b = c
-io.write(a) // expect: c
-io.write(b) // expect: c
-io.write(c) // expect: c
+IO.write(a) // expect: c
+IO.write(b) // expect: c
+IO.write(c) // expect: c

test/assignment/global.wren

@@ -1,8 +1,8 @@
 var a = "before"
-io.write(a) // expect: before
+IO.write(a) // expect: before
 
 a = "after"
-io.write(a) // expect: after
+IO.write(a) // expect: after
 
-io.write(a = "arg") // expect: arg
-io.write(a) // expect: arg
+IO.write(a = "arg") // expect: arg
+IO.write(a) // expect: arg

test/assignment/local.wren

@@ -1,10 +1,10 @@
 fn {
   var a = "before"
-  io.write(a) // expect: before
+  IO.write(a) // expect: before
 
   a = "after"
-  io.write(a) // expect: after
+  IO.write(a) // expect: after
 
-  io.write(a = "arg") // expect: arg
-  io.write(a) // expect: arg
+  IO.write(a = "arg") // expect: arg
+  IO.write(a) // expect: arg
 }.call

test/assignment/syntax.wren

@@ -2,10 +2,10 @@
 var a = "a"
 var b = "b"
 a = b = "chain"
-io.write(a) // expect: chain
-io.write(a) // expect: chain
+IO.write(a) // expect: chain
+IO.write(a) // expect: chain
 
 // Assignment on RHS of variable.
 var c = a = "var"
-io.write(a) // expect: var
-io.write(c) // expect: var
+IO.write(a) // expect: var
+IO.write(c) // expect: var

test/bool/equality.wren

@@ -1,23 +1,23 @@
-io.write(true == true)    // expect: true
-io.write(true == false)   // expect: false
-io.write(false == true)   // expect: false
-io.write(false == false)  // expect: true
+IO.write(true == true)    // expect: true
+IO.write(true == false)   // expect: false
+IO.write(false == true)   // expect: false
+IO.write(false == false)  // expect: true
 
 // Not equal to other types.
-io.write(true == 1)        // expect: false
-io.write(false == 0)       // expect: false
-io.write(true == "true")   // expect: false
-io.write(false == "false") // expect: false
-io.write(false == "")      // expect: false
+IO.write(true == 1)        // expect: false
+IO.write(false == 0)       // expect: false
+IO.write(true == "true")   // expect: false
+IO.write(false == "false") // expect: false
+IO.write(false == "")      // expect: false
 
-io.write(true != true)    // expect: false
-io.write(true != false)   // expect: true
-io.write(false != true)   // expect: true
-io.write(false != false)  // expect: false
+IO.write(true != true)    // expect: false
+IO.write(true != false)   // expect: true
+IO.write(false != true)   // expect: true
+IO.write(false != false)  // expect: false
 
 // Not equal to other types.
-io.write(true != 1)        // expect: true
-io.write(false != 0)       // expect: true
-io.write(true != "true")   // expect: true
-io.write(false != "false") // expect: true
-io.write(false != "")      // expect: true
+IO.write(true != 1)        // expect: true
+IO.write(false != 0)       // expect: true
+IO.write(true != "true")   // expect: true
+IO.write(false != "false") // expect: true
+IO.write(false != "")      // expect: true

test/bool/not.wren

@@ -1,3 +1,3 @@
-io.write(!true)    // expect: false
-io.write(!false)   // expect: true
-io.write(!!true)   // expect: true
+IO.write(!true)    // expect: false
+IO.write(!false)   // expect: true
+IO.write(!!true)   // expect: true

test/bool/to_string.wren

@@ -1,2 +1,2 @@
-io.write(true.toString)  // expect: true
-io.write(false.toString) // expect: false
+IO.write(true.toString)  // expect: true
+IO.write(false.toString) // expect: false

test/bool/type.wren

@@ -1,4 +1,4 @@
-io.write(true is Bool)      // expect: true
-io.write(true is Object)    // expect: true
-io.write(true is Num)       // expect: false
-io.write(true.type == Bool) // expect: true
+IO.write(true is Bool)      // expect: true
+IO.write(true is Object)    // expect: true
+IO.write(true is Num)       // expect: false
+IO.write(true.type == Bool) // expect: true

test/class/equality.wren

@@ -1,13 +1,13 @@
-io.write(Num == Num)  // expect: true
-io.write(Num == Bool) // expect: false
+IO.write(Num == Num)  // expect: true
+IO.write(Num == Bool) // expect: false
 
 // Not equal to other types.
-io.write(Num == 123)  // expect: false
-io.write(Num == true) // expect: false
+IO.write(Num == 123)  // expect: false
+IO.write(Num == true) // expect: false
 
-io.write(Num != Num)  // expect: false
-io.write(Num != Bool) // expect: true
+IO.write(Num != Num)  // expect: false
+IO.write(Num != Bool) // expect: true
 
 // Not equal to other types.
-io.write(Num != 123)  // expect: true
-io.write(Num != true) // expect: true
+IO.write(Num != 123)  // expect: true
+IO.write(Num != true) // expect: true

test/class/name_inside_body.wren

@@ -1,10 +1,10 @@
 class Foo {
   static sayName {
-    io.write(Foo.toString)
+    IO.write(Foo.toString)
   }
 
   sayName {
-    io.write(Foo.toString)
+    IO.write(Foo.toString)
   }
 
   static toString { return "Foo!" }

test/class/new.wren

@@ -1,6 +1,6 @@
 class Foo {}
 
 var foo = new Foo
-io.write(foo is Foo) // expect: true
+IO.write(foo is Foo) // expect: true
 
 // TODO: Test precedence and grammar of what follows "new".

test/closure/assign_to_closure.wren

@@ -4,15 +4,15 @@ var g = null
 {
   var local = "local"
   f = fn {
-    io.write(local)
+    IO.write(local)
     local = "after f"
-    io.write(local)
+    IO.write(local)
   }
 
   g = fn {
-    io.write(local)
+    IO.write(local)
     local = "after g"
-    io.write(local)
+    IO.write(local)
   }
 }
 

test/closure/close_over_function_parameter.wren

@@ -2,7 +2,7 @@ var f = null
 
 fn(param) {
   f = fn {
-    io.write(param)
+    IO.write(param)
   }
 }.call("param")
 

test/closure/close_over_method_parameter.wren

@@ -3,7 +3,7 @@ var f = null
 class Foo {
   method(param) {
     f = fn {
-      io.write(param)
+      IO.write(param)
     }
   }
 }

test/closure/closed_closure_in_function.wren

@@ -3,7 +3,7 @@ var f = null
 {
   var local = "local"
   f = fn {
-    io.write(local)
+    IO.write(local)
   }
 }
 

test/closure/closed_closure_in_method.wren

@@ -4,7 +4,7 @@ var foo = null
   var local = "local"
   class Foo {
     method {
-      io.write(local)
+      IO.write(local)
     }
   }
 

test/closure/nested_closure.wren

@@ -7,9 +7,9 @@ fn {
     fn {
       var c = "c"
       f = fn {
-        io.write(a)
-        io.write(b)
-        io.write(c)
+        IO.write(a)
+        IO.write(b)
+        IO.write(c)
       }
     }.call
   }.call

test/closure/open_closure_in_function.wren

@@ -1,6 +1,6 @@
 {
   var local = "local"
   fn {
-    io.write(local) // expect: local
+    IO.write(local) // expect: local
   }.call
 }

test/closure/open_closure_in_method.wren

@@ -2,7 +2,7 @@
   var local = "local"
   class Foo {
     method {
-      io.write(local)
+      IO.write(local)
     }
   }
 

test/closure/reference_closure_multiple_times.wren

@@ -3,8 +3,8 @@ var f = null
 {
   var a = "a"
   f = fn {
-    io.write(a)
-    io.write(a)
+    IO.write(a)
+    IO.write(a)
   }
 }
 

test/closure/reuse_closure_slot.wren

@@ -3,7 +3,7 @@
 
   {
     var a = "a"
-    f = fn io.write(a)
+    f = fn IO.write(a)
   }
 
   {

test/closure/use_global_in_function.wren

@@ -2,5 +2,5 @@ var global = "global"
 // TODO: Forward reference to global declared after use.
 
 fn {
-  io.write(global) // expect: global
+  IO.write(global) // expect: global
 }.call

test/closure/use_global_in_method.wren

@@ -3,11 +3,11 @@ var global = "global"
 
 class Foo {
   method {
-    io.write(global)
+    IO.write(global)
   }
 
   static classMethod {
-    io.write(global)
+    IO.write(global)
   }
 }
 

test/comments/block.wren

@@ -1,5 +1,5 @@
 // In middle of line.
-io.write/* ... */(/* */"ok"/* */) // expect: ok
+IO.write/* ... */(/* */"ok"/* */) // expect: ok
 
 // Nested.
-io.write(/* in /* nest */ out */"ok") // expect: ok
+IO.write(/* in /* nest */ out */"ok") // expect: ok

test/comments/block_at_eof.wren

@@ -1,2 +1,2 @@
-io.write("ok") // expect: ok
+IO.write("ok") // expect: ok
 /* comment */

test/comments/line_at_eof.wren

@@ -1,2 +1,2 @@
-io.write("ok") // expect: ok
+IO.write("ok") // expect: ok
 // comment

test/comments/unicode.wren

@@ -8,4 +8,4 @@
 
 // TODO: What about combining characters?
 
-io.write("ok") // expect: ok
+IO.write("ok") // expect: ok

test/constructor/default.wren

@@ -4,5 +4,5 @@ class Foo {
 
 // Classes inherit the argument-less "new" one by default.
 var foo = new Foo
-io.write(foo is Foo) // expect: true
-io.write(foo.toString) // expect: Foo
+IO.write(foo is Foo) // expect: true
+IO.write(foo.toString) // expect: Foo

test/constructor/infix_class_expression.wren

@@ -2,6 +2,6 @@ class Foo {
   + other { return "Foo " + other }
 }
 
-io.write(new Foo + "value") // expect: Foo value
+IO.write(new Foo + "value") // expect: Foo value
 
 // TODO: Other expressions following a constructor, like new Foo.bar("arg").

test/constructor/new.wren

@@ -1,7 +1,7 @@
 class Foo {
-  new { io.write("zero") }
-  new(a) { io.write(a) }
-  new(a, b) { io.write(a + b) }
+  new { IO.write("zero") }
+  new(a) { IO.write(a) }
+  new(a, b) { IO.write(a + b) }
 
   toString { return "Foo" }
 }
@@ -13,5 +13,5 @@ new Foo("one", "two") // expect: onetwo
 
 // Returns the new instance.
 var foo = new Foo // expect: zero
-io.write(foo is Foo) // expect: true
-io.write(foo.toString) // expect: Foo
+IO.write(foo is Foo) // expect: true
+IO.write(foo.toString) // expect: Foo

test/constructor/superclass.wren

@@ -1,6 +1,6 @@
 class A {
   new(arg) {
-    io.write("new A " + arg)
+    IO.write("new A " + arg)
     _field = arg
   }
 
@@ -10,7 +10,7 @@ class A {
 class B is A {
   new(arg1, arg2) {
     super(arg2)
-    io.write("new B " + arg1)
+    IO.write("new B " + arg1)
     _field = arg1
   }
 
@@ -20,7 +20,7 @@ class B is A {
 class C is B {
   new {
     super("one", "two")
-    io.write("new C")
+    IO.write("new C")
     _field = "c"
   }
 
@@ -31,10 +31,10 @@ var c = new C
 // expect: new A two
 // expect: new B one
 // expect: new C
-io.write(c is A) // expect: true
-io.write(c is B) // expect: true
-io.write(c is C) // expect: true
+IO.write(c is A) // expect: true
+IO.write(c is B) // expect: true
+IO.write(c is C) // expect: true
 
-io.write(c.aField) // expect: two
-io.write(c.bField) // expect: one
-io.write(c.cField) // expect: c
+IO.write(c.aField) // expect: two
+IO.write(c.bField) // expect: one
+IO.write(c.cField) // expect: c

test/field/default_to_null.wren

@@ -1,5 +1,5 @@
 class Foo {
-  write { io.write(_field) }
+  write { IO.write(_field) }
 }
 
 (new Foo).write // expect: null

test/field/multiple.wren

@@ -7,11 +7,11 @@ class Foo {
     _e = e
   }
   write {
-    io.write(_a)
-    io.write(_b)
-    io.write(_c)
-    io.write(_d)
-    io.write(_e)
+    IO.write(_a)
+    IO.write(_b)
+    IO.write(_c)
+    IO.write(_d)
+    IO.write(_e)
   }
 }
 

test/field/object_reference.wren

@@ -11,7 +11,7 @@ class Node {
       _left.write
     }
 
-    io.write(_value)
+    IO.write(_value)
 
     if (_right is Node) {
       _right.write

test/field/use_before_set.wren

@@ -1,5 +1,5 @@
 class Foo {
-  write { io.write(_field) } // Compile a use of the field...
+  write { IO.write(_field) } // Compile a use of the field...
   init { _field = "value" }  // ...before an assignment to it.
 }
 

test/function/equality.wren

@@ -1,16 +1,16 @@
 // Not structurally equal.
-io.write((fn 123) == (fn 123))  // expect: false
-io.write((fn 123) != (fn 123))  // expect: true
+IO.write((fn 123) == (fn 123))  // expect: false
+IO.write((fn 123) != (fn 123))  // expect: true
 
 // Not equal to other types.
-io.write((fn 123) == 1)         // expect: false
-io.write((fn 123) == false)     // expect: false
-io.write((fn 123) == "fn 123")  // expect: false
-io.write((fn 123) != 1)         // expect: true
-io.write((fn 123) != false)     // expect: true
-io.write((fn 123) != "fn 123")  // expect: true
+IO.write((fn 123) == 1)         // expect: false
+IO.write((fn 123) == false)     // expect: false
+IO.write((fn 123) == "fn 123")  // expect: false
+IO.write((fn 123) != 1)         // expect: true
+IO.write((fn 123) != false)     // expect: true
+IO.write((fn 123) != "fn 123")  // expect: true
 
 // Equal by identity.
 var f = fn 123
-io.write(f == f) // expect: true
-io.write(f != f) // expect: false
+IO.write(f == f) // expect: true
+IO.write(f != f) // expect: false

test/function/parameters.wren

@@ -1,50 +1,50 @@
 var f0 = fn 0
-io.write(f0.call) // expect: 0
+IO.write(f0.call) // expect: 0
 
 var f1 = fn(a) a
-io.write(f1.call(1)) // expect: 1
+IO.write(f1.call(1)) // expect: 1
 
 var f2 = fn(a, b) a + b
-io.write(f2.call(1, 2)) // expect: 3
+IO.write(f2.call(1, 2)) // expect: 3
 
 var f3 = fn(a, b, c) a + b + c
-io.write(f3.call(1, 2, 3)) // expect: 6
+IO.write(f3.call(1, 2, 3)) // expect: 6
 
 var f4 = fn(a, b, c, d) a + b + c + d
-io.write(f4.call(1, 2, 3, 4)) // expect: 10
+IO.write(f4.call(1, 2, 3, 4)) // expect: 10
 
 var f5 = fn(a, b, c, d, e) a + b + c + d + e
-io.write(f5.call(1, 2, 3, 4, 5)) // expect: 15
+IO.write(f5.call(1, 2, 3, 4, 5)) // expect: 15
 
 var f6 = fn(a, b, c, d, e, f) a + b + c + d + e + f
-io.write(f6.call(1, 2, 3, 4, 5, 6)) // expect: 21
+IO.write(f6.call(1, 2, 3, 4, 5, 6)) // expect: 21
 
 var f7 = fn(a, b, c, d, e, f, g) a + b + c + d + e + f + g
-io.write(f7.call(1, 2, 3, 4, 5, 6, 7)) // expect: 28
+IO.write(f7.call(1, 2, 3, 4, 5, 6, 7)) // expect: 28
 
 var f8 = fn(a, b, c, d, e, f, g, h) a + b + c + d + e + f + g + h
-io.write(f8.call(1, 2, 3, 4, 5, 6, 7, 8)) // expect: 36
+IO.write(f8.call(1, 2, 3, 4, 5, 6, 7, 8)) // expect: 36
 
 var f9 = fn(a, b, c, d, e, f, g, h, i) a + b + c + d + e + f + g + h + i
-io.write(f9.call(1, 2, 3, 4, 5, 6, 7, 8, 9)) // expect: 45
+IO.write(f9.call(1, 2, 3, 4, 5, 6, 7, 8, 9)) // expect: 45
 
 var f10 = fn(a, b, c, d, e, f, g, h, i, j) a + b + c + d + e + f + g + h + i + j
-io.write(f10.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)) // expect: 55
+IO.write(f10.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)) // expect: 55
 
 var f11 = fn(a, b, c, d, e, f, g, h, i, j, k) a + b + c + d + e + f + g + h + i + j + k
-io.write(f11.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11)) // expect: 66
+IO.write(f11.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11)) // expect: 66
 
 var f12 = fn(a, b, c, d, e, f, g, h, i, j, k, l) a + b + c + d + e + f + g + h + i + j + k + l
-io.write(f12.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)) // expect: 78
+IO.write(f12.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)) // expect: 78
 
 var f13 = fn(a, b, c, d, e, f, g, h, i, j, k, l, m) a + b + c + d + e + f + g + h + i + j + k + l + m
-io.write(f13.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)) // expect: 91
+IO.write(f13.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)) // expect: 91
 
 var f14 = fn(a, b, c, d, e, f, g, h, i, j, k, l, m, n) a + b + c + d + e + f + g + h + i + j + k + l + m + n
-io.write(f14.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)) // expect: 105
+IO.write(f14.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)) // expect: 105
 
 var f15 = fn(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) a + b + c + d + e + f + g + h + i + j + k + l + m + n + o
-io.write(f15.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)) // expect: 120
+IO.write(f15.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)) // expect: 120
 
 var f16 = fn(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) a + b + c + d + e + f + g + h + i + j + k + l + m + n + o + p
-io.write(f16.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)) // expect: 136
+IO.write(f16.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)) // expect: 136

test/function/syntax.wren

@@ -1,31 +1,31 @@
 // Single expression body.
-(fn io.write("ok")).call // expect: ok
+(fn IO.write("ok")).call // expect: ok
 
 // TODO: Precedence of fn body.
 
 // Curly body.
 fn {
-  io.write("ok") // expect: ok
+  IO.write("ok") // expect: ok
 }.call
 
 // No trailing newline.
 fn {
-  io.write("ok") }.call // expect: ok
+  IO.write("ok") }.call // expect: ok
 
 // Multiple expressions.
 fn {
-  io.write("1") // expect: 1
-  io.write("2") // expect: 2
+  IO.write("1") // expect: 1
+  IO.write("2") // expect: 2
 }.call
 
 // Extra newlines.
 fn {
 
 
-  io.write("1") // expect: 1
+  IO.write("1") // expect: 1
 
 
-  io.write("2") // expect: 2
+  IO.write("2") // expect: 2
 
 
 }.call

test/function/type.wren

@@ -1,4 +1,4 @@
-io.write((fn 0) is Function)      // expect: true
-io.write((fn 0) is Object)        // expect: true
-io.write((fn 0) is String)        // expect: false
-io.write((fn 0).type == Function) // expect: true
+IO.write((fn 0) is Function)      // expect: true
+IO.write((fn 0) is Object)        // expect: true
+IO.write((fn 0) is String)        // expect: false
+IO.write((fn 0).type == Function) // expect: true

test/grammar.wren

@@ -1,31 +1,31 @@
 // * has higher precedence than +.
-io.write(2 + 3 * 4) // expect: 14
+IO.write(2 + 3 * 4) // expect: 14
 
 // * has higher precedence than -.
-io.write(20 - 3 * 4) // expect: 8
+IO.write(20 - 3 * 4) // expect: 8
 
 // / has higher precedence than +.
-io.write(2 + 6 / 3) // expect: 4
+IO.write(2 + 6 / 3) // expect: 4
 
 // / has higher precedence than -.
-io.write(2 - 6 / 3) // expect: 0
+IO.write(2 - 6 / 3) // expect: 0
 
 // < has higher precedence than ==.
-io.write(false == 2 < 1) // expect: true
+IO.write(false == 2 < 1) // expect: true
 
 // > has higher precedence than ==.
-io.write(false == 1 > 2) // expect: true
+IO.write(false == 1 > 2) // expect: true
 
 // <= has higher precedence than ==.
-io.write(false == 2 <= 1) // expect: true
+IO.write(false == 2 <= 1) // expect: true
 
 // >= has higher precedence than ==.
-io.write(false == 1 >= 2) // expect: true
+IO.write(false == 1 >= 2) // expect: true
 
 // Unary - has lower precedence than ..
-io.write(-"abc".count) // expect: -3
+IO.write(-"abc".count) // expect: -3
 
 // TODO: %, associativity.
 
 // Using () for grouping.
-io.write((2 * (6 - (2 + 2)))) // expect: 4
+IO.write((2 * (6 - (2 + 2)))) // expect: 4

test/if.wren

@@ -1,28 +1,28 @@
 // Evaluate the 'then' expression if the condition is true.
-if (true) io.write("good") // expect: good
-if (false) io.write("bad")
+if (true) IO.write("good") // expect: good
+if (false) IO.write("bad")
 
 // Evaluate the 'else' expression if the condition is false.
-if (true) io.write("good") else io.write("bad") // expect: good
-if (false) io.write("bad") else io.write("good") // expect: good
+if (true) IO.write("good") else IO.write("bad") // expect: good
+if (false) IO.write("bad") else IO.write("good") // expect: good
 
 // Allow blocks for branches.
-if (true) { io.write("block") } // expect: block
-if (false) null else { io.write("block") } // expect: block
+if (true) { IO.write("block") } // expect: block
+if (false) null else { IO.write("block") } // expect: block
 
 // Assignment in if condition.
 var a = false
-if (a = true) io.write(a) // expect: true
+if (a = true) IO.write(a) // expect: true
 
 // Newline after "if".
 if
-(true) io.write("good") // expect: good
+(true) IO.write("good") // expect: good
 
 // Newline after "else".
-if (false) io.write("bad") else
-io.write("good") // expect: good
+if (false) IO.write("bad") else
+IO.write("good") // expect: good
 
 // Only false is falsy.
-if (0) io.write(0) // expect: 0
-if (null) io.write(null) // expect: null
-if ("") io.write("empty") // expect: empty
+if (0) IO.write(0) // expect: 0
+if (null) IO.write(null) // expect: null
+if ("") IO.write("empty") // expect: empty

test/inheritance/inherit_fields.wren

@@ -5,8 +5,8 @@ class Foo {
   }
 
   fooPrint {
-    io.write(_field1)
-    io.write(_field2)
+    IO.write(_field1)
+    IO.write(_field2)
   }
 }
 
@@ -17,8 +17,8 @@ class Bar is Foo {
   }
 
   barPrint {
-    io.write(_field1)
-    io.write(_field2)
+    IO.write(_field1)
+    IO.write(_field2)
   }
 }
 

test/inheritance/inherit_methods.wren

@@ -1,15 +1,15 @@
 class Foo {
-  methodOnFoo { io.write("foo") }
-  method(a) { io.write("foo") }
-  method(a, b, c) { io.write("foo") }
-  override { io.write("foo") }
+  methodOnFoo { IO.write("foo") }
+  method(a) { IO.write("foo") }
+  method(a, b, c) { IO.write("foo") }
+  override { IO.write("foo") }
 }
 
 class Bar is Foo {
-  methodOnBar { io.write("bar") }
-  method(a, b) { io.write("bar") }
-  method(a, b, c, d) { io.write("bar") }
-  override { io.write("bar") }
+  methodOnBar { IO.write("bar") }
+  method(a, b) { IO.write("bar") }
+  method(a, b, c, d) { IO.write("bar") }
+  override { IO.write("bar") }
 }
 
 var bar = new Bar

test/inheritance/inherit_static_methods.wren

@@ -1,15 +1,15 @@
 class Foo {
-  static methodOnFoo { io.write("foo") }
-  static method(a) { io.write("foo") }
-  static method(a, b, c) { io.write("foo") }
-  static override { io.write("foo") }
+  static methodOnFoo { IO.write("foo") }
+  static method(a) { IO.write("foo") }
+  static method(a, b, c) { IO.write("foo") }
+  static override { IO.write("foo") }
 }
 
 class Bar is Foo {
-  static methodOnBar { io.write("bar") }
-  static method(a, b) { io.write("bar") }
-  static method(a, b, c, d) { io.write("bar") }
-  static override { io.write("bar") }
+  static methodOnBar { IO.write("bar") }
+  static method(a, b) { IO.write("bar") }
+  static method(a, b, c, d) { IO.write("bar") }
+  static override { IO.write("bar") }
 }
 
 Bar.methodOnFoo // expect: foo

test/inheritance/is.wren

@@ -5,12 +5,12 @@ var a = new A
 var b = new B
 var c = new C
 
-io.write(a is A) // expect: true
-io.write(a is B) // expect: false
-io.write(a is C) // expect: false
-io.write(b is A) // expect: true
-io.write(b is B) // expect: true
-io.write(b is C) // expect: false
-io.write(c is A) // expect: true
-io.write(c is B) // expect: true
-io.write(c is C) // expect: true
+IO.write(a is A) // expect: true
+IO.write(a is B) // expect: false
+IO.write(a is C) // expect: false
+IO.write(b is A) // expect: true
+IO.write(b is B) // expect: true
+IO.write(b is C) // expect: false
+IO.write(c is A) // expect: true
+IO.write(c is B) // expect: true
+IO.write(c is C) // expect: true

test/is.wren

@@ -1,32 +1,32 @@
-io.write(Num is Class) // expect: true
-io.write(true is Bool) // expect: true
-io.write((fn 1) is Function) // expect: true
-io.write(123 is Num) // expect: true
-io.write(null is Null) // expect: true
-io.write("s" is String) // expect: true
+IO.write(Num is Class) // expect: true
+IO.write(true is Bool) // expect: true
+IO.write((fn 1) is Function) // expect: true
+IO.write(123 is Num) // expect: true
+IO.write(null is Null) // expect: true
+IO.write("s" is String) // expect: true
 
-io.write(Num is Bool) // expect: false
-io.write(null is Class) // expect: false
-io.write(true is Function) // expect: false
-io.write((fn 1) is Num) // expect: false
-io.write("s" is Null) // expect: false
-io.write(123 is String) // expect: false
+IO.write(Num is Bool) // expect: false
+IO.write(null is Class) // expect: false
+IO.write(true is Function) // expect: false
+IO.write((fn 1) is Num) // expect: false
+IO.write("s" is Null) // expect: false
+IO.write(123 is String) // expect: false
 
 // Everything extends Object.
-io.write(Num is Object) // expect: true
-io.write(null is Object) // expect: true
-io.write(true is Object) // expect: true
-io.write((fn 1) is Object) // expect: true
-io.write("s" is Object) // expect: true
-io.write(123 is Object) // expect: true
+IO.write(Num is Object) // expect: true
+IO.write(null is Object) // expect: true
+IO.write(true is Object) // expect: true
+IO.write((fn 1) is Object) // expect: true
+IO.write("s" is Object) // expect: true
+IO.write(123 is Object) // expect: true
 
 // Classes extend Class.
-io.write(Num is Class) // expect: true
-io.write(null is Class) // expect: false
-io.write(true is Class) // expect: false
-io.write((fn 1) is Class) // expect: false
-io.write("s" is Class) // expect: false
-io.write(123 is Class) // expect: false
+IO.write(Num is Class) // expect: true
+IO.write(null is Class) // expect: false
+IO.write(true is Class) // expect: false
+IO.write((fn 1) is Class) // expect: false
+IO.write("s" is Class) // expect: false
+IO.write(123 is Class) // expect: false
 
 // TODO: Non-class on RHS.
 // TODO: Precedence and associativity.

test/list/add.wren

@@ -1,10 +1,10 @@
 var a = []
 a.add(1)
-io.write(a) // expect: [1]
+IO.write(a) // expect: [1]
 a.add(2)
-io.write(a) // expect: [1, 2]
+IO.write(a) // expect: [1, 2]
 a.add(3)
-io.write(a) // expect: [1, 2, 3]
+IO.write(a) // expect: [1, 2, 3]
 
 // Returns added element.
-io.write(a.add(4)) // expect: 4
+IO.write(a.add(4)) // expect: 4

test/list/clear.wren

@@ -1,7 +1,7 @@
 var a = [1, 2, 3]
 a.clear
-io.write(a)       // expect: []
-io.write(a.count) // expect: 0
+IO.write(a)       // expect: []
+IO.write(a.count) // expect: 0
 
 // Returns null.
-io.write([1, 2].clear) // expect: null
+IO.write([1, 2].clear) // expect: null

test/list/count.wren

@@ -1,3 +1,3 @@
-io.write([].count)           // expect: 0
-io.write([1].count)          // expect: 1
-io.write([1, 2, 3, 4].count) // expect: 4
+IO.write([].count)           // expect: 0
+IO.write([1].count)          // expect: 1
+IO.write([1, 2, 3, 4].count) // expect: 4

test/list/insert.wren

@@ -4,41 +4,41 @@
 // Add to empty list.
 var a = []
 a.insert(1, 0)
-io.write(a) // expect: [1]
+IO.write(a) // expect: [1]
 
 // Normal indices.
 var b = [1, 2, 3]
 b.insert(4, 0)
-io.write(b) // expect: [4, 1, 2, 3]
+IO.write(b) // expect: [4, 1, 2, 3]
 
 var c = [1, 2, 3]
 c.insert(4, 1)
-io.write(c) // expect: [1, 4, 2, 3]
+IO.write(c) // expect: [1, 4, 2, 3]
 
 var d = [1, 2, 3]
 d.insert(4, 2)
-io.write(d) // expect: [1, 2, 4, 3]
+IO.write(d) // expect: [1, 2, 4, 3]
 
 var e = [1, 2, 3]
 e.insert(4, 3)
-io.write(e) // expect: [1, 2, 3, 4]
+IO.write(e) // expect: [1, 2, 3, 4]
 
 // Negative indices.
 var f = [1, 2, 3]
 f.insert(4, -4)
-io.write(f) // expect: [4, 1, 2, 3]
+IO.write(f) // expect: [4, 1, 2, 3]
 
 var g = [1, 2, 3]
 g.insert(4, -3)
-io.write(g) // expect: [1, 4, 2, 3]
+IO.write(g) // expect: [1, 4, 2, 3]
 
 var h = [1, 2, 3]
 h.insert(4, -2)
-io.write(h) // expect: [1, 2, 4, 3]
+IO.write(h) // expect: [1, 2, 4, 3]
 
 var i = [1, 2, 3]
 i.insert(4, -1)
-io.write(i) // expect: [1, 2, 3, 4]
+IO.write(i) // expect: [1, 2, 3, 4]
 
 // Returns.inserted value.
-io.write([1, 2].insert(3, 0)) // expect: 3
+IO.write([1, 2].insert(3, 0)) // expect: 3

test/list/newlines.wren

@@ -8,7 +8,7 @@ var list = [
 
 ]
 
-io.write(list[0]) // expect: a
-io.write(list[1]) // expect: b
-io.write(list[2]) // expect: c
-io.write(list[3]) // expect: d
+IO.write(list[0]) // expect: a
+IO.write(list[1]) // expect: b
+IO.write(list[2]) // expect: c
+IO.write(list[3]) // expect: d

test/list/remove_at.wren

@@ -1,32 +1,32 @@
 var a = [1, 2, 3]
 a.removeAt(0)
-io.write(a) // expect: [2, 3]
+IO.write(a) // expect: [2, 3]
 
 var b = [1, 2, 3]
 b.removeAt(1)
-io.write(b) // expect: [1, 3]
+IO.write(b) // expect: [1, 3]
 
 var c = [1, 2, 3]
 c.removeAt(2)
-io.write(c) // expect: [1, 2]
+IO.write(c) // expect: [1, 2]
 
 // Index backwards from end.
 var d = [1, 2, 3]
 d.removeAt(-3)
-io.write(d) // expect: [2, 3]
+IO.write(d) // expect: [2, 3]
 
 var e = [1, 2, 3]
 e.removeAt(-2)
-io.write(e) // expect: [1, 3]
+IO.write(e) // expect: [1, 3]
 
 var f = [1, 2, 3]
 f.removeAt(-1)
-io.write(f) // expect: [1, 2]
+IO.write(f) // expect: [1, 2]
 
 // Out of bounds.
 // TODO: Signal error in better way.
-io.write([1, 2, 3].removeAt(3)) // expect: null
-io.write([1, 2, 3].removeAt(-4)) // expect: null
+IO.write([1, 2, 3].removeAt(3)) // expect: null
+IO.write([1, 2, 3].removeAt(-4)) // expect: null
 
 // Return the removed value.
-io.write([3, 4, 5].removeAt(1)) // expect: 4
+IO.write([3, 4, 5].removeAt(1)) // expect: 4

test/list/subscript.wren

@@ -1,25 +1,25 @@
 // Returns elements.
 var list = ["a", "b", "c", "d"]
-io.write(list[0]) // expect: a
-io.write(list[1]) // expect: b
-io.write(list[2]) // expect: c
-io.write(list[3]) // expect: d
+IO.write(list[0]) // expect: a
+IO.write(list[1]) // expect: b
+IO.write(list[2]) // expect: c
+IO.write(list[3]) // expect: d
 
 // Allows indexing backwards from the end.
-io.write(list[-4]) // expect: a
-io.write(list[-3]) // expect: b
-io.write(list[-2]) // expect: c
-io.write(list[-1]) // expect: d
+IO.write(list[-4]) // expect: a
+IO.write(list[-3]) // expect: b
+IO.write(list[-2]) // expect: c
+IO.write(list[-1]) // expect: d
 
 // Handle out of bounds.
 // TODO: Should halt the fiber or raise an error somehow.
-io.write(list[4])  // expect: null
-io.write(list[-5]) // expect: null
+IO.write(list[4])  // expect: null
+IO.write(list[-5]) // expect: null
 
 // Handle wrong argument type.
 // TODO: Should halt the fiber or raise an error somehow.
-io.write(list[true]) // expect: null
+IO.write(list[true]) // expect: null
 
 // Handle non-integer index.
 // TODO: Should halt the fiber or raise an error somehow.
-io.write(list[1.5]) // expect: null
+IO.write(list[1.5]) // expect: null

test/list/subscript_setter.wren

@@ -4,13 +4,13 @@
   list[0] = 5
   list[1] = 6
   list[2] = 7
-  io.write(list) // expect: [5, 6, 7]
+  IO.write(list) // expect: [5, 6, 7]
 }
 
 // Returns right-hand side.
 {
   var list = [1, 2, 3]
-  io.write(list[1] = 5) // expect: 5
+  IO.write(list[1] = 5) // expect: 5
 }
 
 // Negative indices.
@@ -19,7 +19,7 @@
   list[-1] = 5
   list[-2] = 6
   list[-3] = 7
-  io.write(list) // expect: [7, 6, 5]
+  IO.write(list) // expect: [7, 6, 5]
 }
 
 // TODO: Handle out of range.

test/list/type.wren

@@ -1,4 +1,4 @@
-io.write([] is List)      // expect: true
-io.write([] is Object)    // expect: true
-io.write([] is Bool)      // expect: false
-io.write([].type == List) // expect: true
+IO.write([] is List)      // expect: true
+IO.write([] is Object)    // expect: true
+IO.write([] is Bool)      // expect: false
+IO.write([].type == List) // expect: true

test/method/arity.wren

@@ -19,20 +19,20 @@ class Foo {
 }
 
 var foo = new Foo
-io.write(foo.method) // expect: 0
-io.write(foo.method(1)) // expect: 1
-io.write(foo.method(1, 2)) // expect: 3
-io.write(foo.method(1, 2, 3)) // expect: 6
-io.write(foo.method(1, 2, 3, 4)) // expect: 10
-io.write(foo.method(1, 2, 3, 4, 5)) // expect: 15
-io.write(foo.method(1, 2, 3, 4, 5, 6)) // expect: 21
-io.write(foo.method(1, 2, 3, 4, 5, 6, 7)) // expect: 28
-io.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8)) // expect: 36
-io.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9)) // expect: 45
-io.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)) // expect: 55
-io.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11)) // expect: 66
-io.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)) // expect: 78
-io.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)) // expect: 91
-io.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)) // expect: 105
-io.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)) // expect: 120
-io.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)) // expect: 136
+IO.write(foo.method) // expect: 0
+IO.write(foo.method(1)) // expect: 1
+IO.write(foo.method(1, 2)) // expect: 3
+IO.write(foo.method(1, 2, 3)) // expect: 6
+IO.write(foo.method(1, 2, 3, 4)) // expect: 10
+IO.write(foo.method(1, 2, 3, 4, 5)) // expect: 15
+IO.write(foo.method(1, 2, 3, 4, 5, 6)) // expect: 21
+IO.write(foo.method(1, 2, 3, 4, 5, 6, 7)) // expect: 28
+IO.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8)) // expect: 36
+IO.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9)) // expect: 45
+IO.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)) // expect: 55
+IO.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11)) // expect: 66
+IO.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)) // expect: 78
+IO.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)) // expect: 91
+IO.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)) // expect: 105
+IO.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)) // expect: 120
+IO.write(foo.method(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)) // expect: 136

test/method/long_name.wren

@@ -4,4 +4,4 @@ class Foo {
   }
 }
 
-io.write((new Foo).thisHasAMethodNameThatIsExactly64CharactersLongWhichIsTheMaximum) // expect: result
+IO.write((new Foo).thisHasAMethodNameThatIsExactly64CharactersLongWhichIsTheMaximum) // expect: result

test/method/operators.wren

@@ -16,16 +16,16 @@ class Foo {
 }
 
 var foo = new Foo
-io.write(foo + "a") // expect: infix + a
-io.write(foo - "a") // expect: infix - a
-io.write(foo * "a") // expect: infix * a
-io.write(foo / "a") // expect: infix / a
-io.write(foo % "a") // expect: infix % a
-io.write(foo < "a") // expect: infix < a
-io.write(foo > "a") // expect: infix > a
-io.write(foo <= "a") // expect: infix <= a
-io.write(foo >= "a") // expect: infix >= a
-io.write(foo == "a") // expect: infix == a
-io.write(foo != "a") // expect: infix != a
-io.write(!foo) // expect: prefix !
-io.write(-foo) // expect: prefix -
+IO.write(foo + "a") // expect: infix + a
+IO.write(foo - "a") // expect: infix - a
+IO.write(foo * "a") // expect: infix * a
+IO.write(foo / "a") // expect: infix / a
+IO.write(foo % "a") // expect: infix % a
+IO.write(foo < "a") // expect: infix < a
+IO.write(foo > "a") // expect: infix > a
+IO.write(foo <= "a") // expect: infix <= a
+IO.write(foo >= "a") // expect: infix >= a
+IO.write(foo == "a") // expect: infix == a
+IO.write(foo != "a") // expect: infix != a
+IO.write(!foo) // expect: prefix !
+IO.write(-foo) // expect: prefix -

test/method/static.wren

@@ -6,7 +6,7 @@ class Foo {
   static bar(arg) { return "on metaclass " + arg }
 }
 
-io.write((new Foo).bar)        // expect: on instance
-io.write(Foo.bar)              // expect: on metaclass
-io.write((new Foo).bar("arg")) // expect: on instance arg
-io.write(Foo.bar("arg"))       // expect: on metaclass arg
+IO.write((new Foo).bar)        // expect: on instance
+IO.write(Foo.bar)              // expect: on metaclass
+IO.write((new Foo).bar("arg")) // expect: on instance arg
+IO.write(Foo.bar("arg"))       // expect: on metaclass arg

test/method/too_many_arguments.wren

@@ -1 +1 @@
-io.write(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17) // expect error
+IO.write(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17) // expect error

test/no_trailing_newline.wren

@@ -1 +1 @@
-io.write("ok") // expect: ok
+IO.write("ok") // expect: ok

test/null.wren

@@ -1 +1 @@
-io.write(null) // expect: null
+IO.write(null) // expect: null

test/null_type.wren

@@ -1,4 +1,4 @@
-io.write(null is Null)      // expect: true
-io.write(null is Object)    // expect: true
-io.write(null is Bool)      // expect: false
-io.write(null.type == Null) // expect: true
+IO.write(null is Null)      // expect: true
+IO.write(null is Object)    // expect: true
+IO.write(null is Bool)      // expect: false
+IO.write(null.type == Null) // expect: true

test/number/abs.wren

@@ -1,6 +1,6 @@
-io.write(123.abs)    // expect: 123
-io.write(-123.abs)   // expect: 123
-io.write(0.abs)      // expect: 0
-io.write(-0.abs)     // expect: 0
-io.write(-0.12.abs)  // expect: 0.12
-io.write(12.34.abs)  // expect: 12.34
+IO.write(123.abs)    // expect: 123
+IO.write(-123.abs)   // expect: 123
+IO.write(0.abs)      // expect: 0
+IO.write(-0.abs)     // expect: 0
+IO.write(-0.12.abs)  // expect: 0.12
+IO.write(12.34.abs)  // expect: 12.34

test/number/bitwise_not.wren

@@ -1,22 +1,22 @@
-io.write(~0) // expect: 4294967295
-io.write(~1) // expect: 4294967294
-io.write(~23) // expect: 4294967272
+IO.write(~0) // expect: 4294967295
+IO.write(~1) // expect: 4294967294
+IO.write(~23) // expect: 4294967272
 
 // Max u32 value.
-io.write(~4294967295) // expect: 0
+IO.write(~4294967295) // expect: 0
 
 // Past max u32 value.
-io.write(~4294967296) // expect: 4294967295
+IO.write(~4294967296) // expect: 4294967295
 
 // Negative numbers.
-io.write(~-1) // expect: 0
-io.write(~-123) // expect: 122
-io.write(~-4294967294) // expect: 4294967293
-io.write(~-4294967295) // expect: 4294967294
-io.write(~-4294967296) // expect: 4294967295
+IO.write(~-1) // expect: 0
+IO.write(~-123) // expect: 122
+IO.write(~-4294967294) // expect: 4294967293
+IO.write(~-4294967295) // expect: 4294967294
+IO.write(~-4294967296) // expect: 4294967295
 
 // Floating point values.
-io.write(~1.23) // expect: 4294967294
-io.write(~0.00123) // expect: 4294967295
-io.write(~345.67) // expect: 4294966950
-io.write(~-12.34) // expect: 11
+IO.write(~1.23) // expect: 4294967294
+IO.write(~0.00123) // expect: 4294967295
+IO.write(~345.67) // expect: 4294966950
+IO.write(~-12.34) // expect: 11

test/number/comparison.wren

@@ -1,27 +1,27 @@
-io.write(1 < 2)    // expect: true
-io.write(2 < 2)    // expect: false
-io.write(2 < 1)    // expect: false
+IO.write(1 < 2)    // expect: true
+IO.write(2 < 2)    // expect: false
+IO.write(2 < 1)    // expect: false
 
-io.write(1 <= 2)    // expect: true
-io.write(2 <= 2)    // expect: true
-io.write(2 <= 1)    // expect: false
+IO.write(1 <= 2)    // expect: true
+IO.write(2 <= 2)    // expect: true
+IO.write(2 <= 1)    // expect: false
 
-io.write(1 > 2)    // expect: false
-io.write(2 > 2)    // expect: false
-io.write(2 > 1)    // expect: true
+IO.write(1 > 2)    // expect: false
+IO.write(2 > 2)    // expect: false
+IO.write(2 > 1)    // expect: true
 
-io.write(1 >= 2)    // expect: false
-io.write(2 >= 2)    // expect: true
-io.write(2 >= 1)    // expect: true
+IO.write(1 >= 2)    // expect: false
+IO.write(2 >= 2)    // expect: true
+IO.write(2 >= 1)    // expect: true
 
 // Zero and negative zero compare the same.
-io.write(0 < -0) // expect: false
-io.write(-0 < 0) // expect: false
-io.write(0 > -0) // expect: false
-io.write(-0 > 0) // expect: false
-io.write(0 <= -0) // expect: true
-io.write(-0 <= 0) // expect: true
-io.write(0 >= -0) // expect: true
-io.write(-0 >= 0) // expect: true
+IO.write(0 < -0) // expect: false
+IO.write(-0 < 0) // expect: false
+IO.write(0 > -0) // expect: false
+IO.write(-0 > 0) // expect: false
+IO.write(0 <= -0) // expect: true
+IO.write(-0 <= 0) // expect: true
+IO.write(0 >= -0) // expect: true
+IO.write(-0 >= 0) // expect: true
 
 // TODO: Wrong type for RHS.

test/number/divide.wren

@@ -1,5 +1,5 @@
-io.write(8 / 2)        // expect: 4
-io.write(12.34 / -0.4) // expect: -30.85
+IO.write(8 / 2)        // expect: 4
+IO.write(12.34 / -0.4) // expect: -30.85
 
 // TODO: Unsupported RHS types.
 // TODO: Divide by zero.

test/number/equality.wren

@@ -1,19 +1,19 @@
-io.write(123 == 123)  // expect: true
-io.write(123 == 124)  // expect: false
-io.write(-3 == 3)     // expect: false
-io.write(0 == -0)     // expect: true
+IO.write(123 == 123)  // expect: true
+IO.write(123 == 124)  // expect: false
+IO.write(-3 == 3)     // expect: false
+IO.write(0 == -0)     // expect: true
 
 // Not equal to other types.
-io.write(123 == "123") // expect: false
-io.write(1 == true)    // expect: false
-io.write(0 == false)   // expect: false
+IO.write(123 == "123") // expect: false
+IO.write(1 == true)    // expect: false
+IO.write(0 == false)   // expect: false
 
-io.write(123 != 123)  // expect: false
-io.write(123 != 124)  // expect: true
-io.write(-3 != 3)     // expect: true
-io.write(0 != -0)     // expect: false
+IO.write(123 != 123)  // expect: false
+IO.write(123 != 124)  // expect: true
+IO.write(-3 != 3)     // expect: true
+IO.write(0 != -0)     // expect: false
 
 // Not equal to other types.
-io.write(123 != "123") // expect: true
-io.write(1 != true)    // expect: true
-io.write(0 != false)   // expect: true
+IO.write(123 != "123") // expect: true
+IO.write(1 != true)    // expect: true
+IO.write(0 != false)   // expect: true

test/number/literals.wren

@@ -1,10 +1,10 @@
-io.write(123)     // expect: 123
-io.write(987654)  // expect: 987654
-io.write(0)       // expect: 0
-io.write(-0)      // expect: -0
+IO.write(123)     // expect: 123
+IO.write(987654)  // expect: 987654
+IO.write(0)       // expect: 0
+IO.write(-0)      // expect: -0
 
-io.write(123.456) // expect: 123.456
-io.write(-0.001)  // expect: -0.001
+IO.write(123.456) // expect: 123.456
+IO.write(-0.001)  // expect: -0.001
 
 // TODO: Hex? Scientific notation?
 // TODO: Literals at and beyond numeric limits.

test/number/minus.wren

@@ -1,10 +1,10 @@
 // Infix.
-io.write(5 - 3)      // expect: 2
-io.write(3.1 - 0.24) // expect: 2.86
-io.write(3 - 2 - 1)  // expect: 0
+IO.write(5 - 3)      // expect: 2
+IO.write(3.1 - 0.24) // expect: 2.86
+IO.write(3 - 2 - 1)  // expect: 0
 
 // Unary negation.
 var a = 3
-io.write(-a) // expect: -3
+IO.write(-a) // expect: -3
 
 // TODO: Unsupported RHS types.

test/number/mod.wren

@@ -1,14 +1,14 @@
-io.write(5 % 3) // expect: 2
-io.write(10 % 5) // expect: 0
-io.write(-4 % 3) // expect: -1
-io.write(4 % -3) // expect: 1
-io.write(-4 % -3) // expect: -1
-io.write(-4.2 % 3.1) // expect: -1.1
-io.write(4.2 % -3.1) // expect: 1.1
-io.write(-4.2 % -3.1) // expect: -1.1
+IO.write(5 % 3) // expect: 2
+IO.write(10 % 5) // expect: 0
+IO.write(-4 % 3) // expect: -1
+IO.write(4 % -3) // expect: 1
+IO.write(-4 % -3) // expect: -1
+IO.write(-4.2 % 3.1) // expect: -1.1
+IO.write(4.2 % -3.1) // expect: 1.1
+IO.write(-4.2 % -3.1) // expect: -1.1
 
 // Left associative.
-io.write(13 % 7 % 4) // expect: 2
+IO.write(13 % 7 % 4) // expect: 2
 
 // TODO: Unsupported RHS types.
 // TODO: Error on mod by zero.

test/number/multiply.wren

@@ -1,4 +1,4 @@
-io.write(5 * 3) // expect: 15
-io.write(12.34 * 0.3) // expect: 3.702
+IO.write(5 * 3) // expect: 15
+IO.write(12.34 * 0.3) // expect: 3.702
 
 // TODO: Unsupported RHS types.

test/number/plus.wren

@@ -1,5 +1,5 @@
-io.write(1 + 2) // expect: 3
-io.write(12.34 + 0.13) // expect: 12.47
-io.write(3 + 5 + 2) // expect: 10
+IO.write(1 + 2) // expect: 3
+IO.write(12.34 + 0.13) // expect: 12.47
+IO.write(3 + 5 + 2) // expect: 10
 
 // TODO: Unsupported RHS types.

test/number/to_string.wren

@@ -1,5 +1,5 @@
-io.write(123.toString == "123") // expect: true
-io.write(-123.toString == "-123") // expect: true
-io.write(-0.toString == "-0") // expect: true
-io.write(12.34.toString == "12.34") // expect: true
-io.write(-0.0001.toString == "-0.0001") // expect: true
+IO.write(123.toString == "123") // expect: true
+IO.write(-123.toString == "-123") // expect: true
+IO.write(-0.toString == "-0") // expect: true
+IO.write(12.34.toString == "12.34") // expect: true
+IO.write(-0.0001.toString == "-0.0001") // expect: true

test/number/type.wren

@@ -1,4 +1,4 @@
-io.write(123 is Num)      // expect: true
-io.write(123 is Object)   // expect: true
-io.write(123 is String)   // expect: false
-io.write(123.type == Num) // expect: true
+IO.write(123 is Num)      // expect: true
+IO.write(123 is Object)   // expect: true
+IO.write(123 is String)   // expect: false
+IO.write(123.type == Num) // expect: true

test/or.wren

@@ -1,26 +1,26 @@
 // Note: These tests implicitly depend on ints being truthy.
-//       Also rely on io.write() returning its argument.
+//       Also rely on IO.write() returning its argument.
 
 // Return the first true argument.
-io.write(1 || true) // expect: 1
-io.write(false || 1) // expect: 1
-io.write(false || false || true) // expect: true
+IO.write(1 || true) // expect: 1
+IO.write(false || 1) // expect: 1
+IO.write(false || false || true) // expect: true
 
 // Return the last argument if all are false.
-io.write(false || false) // expect: false
-io.write(false || false || false) // expect: false
+IO.write(false || false) // expect: false
+IO.write(false || false || false) // expect: false
 
 // Short-circuit at the first true argument.
-io.write(false) || // expect: false
-    io.write(true) || // expect: true
-    io.write(true) // should not print
+IO.write(false) || // expect: false
+    IO.write(true) || // expect: true
+    IO.write(true) // should not print
 
 // Swallow a trailing newline.
-io.write(true ||
+IO.write(true ||
     true) // expect: true
 
 // Only false is falsy.
-io.write(0 || true) // expect: 0
-io.write(null || true) // expect: null
-io.write(("" || true) == "") // expect: true
-io.write(false || true) // expect: true
+IO.write(0 || true) // expect: 0
+IO.write(null || true) // expect: null
+IO.write(("" || true) == "") // expect: true
+IO.write(false || true) // expect: true

test/semicolon.wren

@@ -1 +1 @@
-var a = "ok"; io.write(a) // expect: ok
+var a = "ok"; IO.write(a) // expect: ok

test/setter/associativity.wren

@@ -13,6 +13,6 @@ var c = new Foo("c")
 
 // Assignment is right-associative.
 a.bar = b.bar = c.bar = "d"
-io.write(a.toString) // expect: d
-io.write(b.toString) // expect: d
-io.write(c.toString) // expect: d
+IO.write(a.toString) // expect: d
+IO.write(b.toString) // expect: d
+IO.write(c.toString) // expect: d

test/setter/instance.wren

@@ -1,6 +1,6 @@
 class Foo {
   bar = value {
-    io.write(value)
+    IO.write(value)
   }
 }
 

test/setter/result.wren

@@ -3,4 +3,4 @@ class Foo {
 }
 
 var foo = new Foo
-io.write(foo.bar = "value") // expect: result
+IO.write(foo.bar = "value") // expect: result

test/setter/same_name_as_method.wren

@@ -1,6 +1,6 @@
 class Foo {
-  bar = value { io.write("set") }
-  bar { io.write("get") }
+  bar = value { IO.write("set") }
+  bar { IO.write("get") }
 }
 
 var foo = new Foo

test/setter/static.wren

@@ -1,6 +1,6 @@
 class Foo {
   static bar = value {
-    io.write(value)
+    IO.write(value)
   }
 }
 

test/string/contains.wren

@@ -1,8 +1,8 @@
-io.write("".contains(""))              // expect: true
-io.write("anything".contains(""))      // expect: true
-io.write("something".contains("meth")) // expect: true
-io.write("something".contains("some")) // expect: true
-io.write("something".contains("ing"))  // expect: true
-io.write("something".contains("math")) // expect: false
+IO.write("".contains(""))              // expect: true
+IO.write("anything".contains(""))      // expect: true
+IO.write("something".contains("meth")) // expect: true
+IO.write("something".contains("some")) // expect: true
+IO.write("something".contains("ing"))  // expect: true
+IO.write("something".contains("math")) // expect: false
 
 // TODO: Passing non-string as argument.

test/string/count.wren

@@ -1,2 +1,2 @@
-io.write("".count)   // expect: 0
-io.write("a string".count) // expect: 8
+IO.write("".count)   // expect: 0
+IO.write("a string".count) // expect: 8

test/string/equality.wren

@@ -1,19 +1,19 @@
-io.write("" == "")          // expect: true
-io.write("abcd" == "abcd")  // expect: true
-io.write("abcd" == "d")     // expect: false
-io.write("e" == "abcd")     // expect: false
-io.write("" == "abcd")      // expect: false
+IO.write("" == "")          // expect: true
+IO.write("abcd" == "abcd")  // expect: true
+IO.write("abcd" == "d")     // expect: false
+IO.write("e" == "abcd")     // expect: false
+IO.write("" == "abcd")      // expect: false
 
 // Not equal to other types.
-io.write("1" == 1)        // expect: false
-io.write("true" == true)  // expect: false
+IO.write("1" == 1)        // expect: false
+IO.write("true" == true)  // expect: false
 
-io.write("" != "")          // expect: false
-io.write("abcd" != "abcd")  // expect: false
-io.write("abcd" != "d")     // expect: true
-io.write("e" != "abcd")     // expect: true
-io.write("" != "abcd")      // expect: true
+IO.write("" != "")          // expect: false
+IO.write("abcd" != "abcd")  // expect: false
+IO.write("abcd" != "d")     // expect: true
+IO.write("e" != "abcd")     // expect: true
+IO.write("" != "abcd")      // expect: true
 
 // Not equal to other types.
-io.write("1" != 1)        // expect: true
-io.write("true" != true)  // expect: true
+IO.write("1" != 1)        // expect: true
+IO.write("true" != true)  // expect: true

test/string/escapes.wren

@@ -1,7 +1,7 @@
 // Escape characters.
-io.write("\"")     // expect: "
-io.write("\\")     // expect: \
-io.write("(\n)")   // expect: (
+IO.write("\"")     // expect: "
+IO.write("\\")     // expect: \
+IO.write("(\n)")   // expect: (
                    // expect: )
 
 // TODO: Non-printing escapes like \t.

test/string/literals.wren

@@ -1,2 +1,2 @@
-io.write("".count)   // expect: 0
-io.write("a string") // expect: a string
+IO.write("".count)   // expect: 0
+IO.write("a string") // expect: a string

test/string/subscript.wren

@@ -1,24 +1,24 @@
 // Returns characters (as strings).
-io.write("abcd"[0]) // expect: a
-io.write("abcd"[1]) // expect: b
-io.write("abcd"[2]) // expect: c
-io.write("abcd"[3]) // expect: d
+IO.write("abcd"[0]) // expect: a
+IO.write("abcd"[1]) // expect: b
+IO.write("abcd"[2]) // expect: c
+IO.write("abcd"[3]) // expect: d
 
 // Allows indexing backwards from the end.
-io.write("abcd"[-4]) // expect: a
-io.write("abcd"[-3]) // expect: b
-io.write("abcd"[-2]) // expect: c
-io.write("abcd"[-1]) // expect: d
+IO.write("abcd"[-4]) // expect: a
+IO.write("abcd"[-3]) // expect: b
+IO.write("abcd"[-2]) // expect: c
+IO.write("abcd"[-1]) // expect: d
 
 // Handle out of bounds.
 // TODO: Should halt the fiber or raise an error somehow.
-io.write("abcd"[4])  // expect: null
-io.write("abcd"[-5]) // expect: null
+IO.write("abcd"[4])  // expect: null
+IO.write("abcd"[-5]) // expect: null
 
 // Handle wrong argument type.
 // TODO: Should halt the fiber or raise an error somehow.
-io.write("abcd"[true]) // expect: null
+IO.write("abcd"[true]) // expect: null
 
 // Handle non-integer index.
 // TODO: Should halt the fiber or raise an error somehow.
-io.write("abcd"[1.5]) // expect: null
+IO.write("abcd"[1.5]) // expect: null

test/string/to_string.wren

@@ -1,2 +1,2 @@
-io.write("".toString == "") // expect: true
-io.write("blah".toString == "blah") // expect: true
+IO.write("".toString == "") // expect: true
+IO.write("blah".toString == "blah") // expect: true

test/string/type.wren

@@ -1,4 +1,4 @@
-io.write("s" is String)      // expect: true
-io.write("s" is Object)      // expect: true
-io.write("s" is Num)         // expect: false
-io.write("s".type == String) // expect: true
+IO.write("s" is String)      // expect: true
+IO.write("s" is Object)      // expect: true
+IO.write("s" is Num)         // expect: false
+IO.write("s".type == String) // expect: true

test/super/call_other_method.wren

@@ -1,12 +1,12 @@
 class Base {
   foo {
-    io.write("Base.foo")
+    IO.write("Base.foo")
   }
 }
 
 class Derived is Base {
   bar {
-    io.write("Derived.bar")
+    IO.write("Derived.bar")
     super.foo
   }
 }

test/super/call_same_method.wren

@@ -1,12 +1,12 @@
 class Base {
   foo {
-    io.write("Base.foo")
+    IO.write("Base.foo")
   }
 }
 
 class Derived is Base {
   foo {
-    io.write("Derived.foo")
+    IO.write("Derived.foo")
     super.foo
   }
 }

test/super/indirectly_inherited.wren

@@ -1,6 +1,6 @@
 class A {
   foo {
-    io.write("A.foo")
+    IO.write("A.foo")
   }
 }
 
@@ -8,7 +8,7 @@ class B is A {}
 
 class C is B {
   foo {
-    io.write("C.foo")
+    IO.write("C.foo")
     super.foo
   }
 }

test/this/closure.wren

@@ -9,4 +9,4 @@ class Foo {
 }
 
 var closure = (new Foo).getClosure
-io.write(closure.call) // expect: Foo
+IO.write(closure.call) // expect: Foo