Add TypeMap with test.

README.md

@@ -408,4 +408,8 @@ Here, `Value` will just use a plain expression, whereas `Arg` and `OptArg` will
 
 ### Expression Level Transformation
 
-Because the state of a constructor is rather delicate, the API prohibits you to just mess around with the whole constructor body at an expression level. For that to happen, you can register `onGenerate` hooks. These will be called when the corresponding `ClassBuilder` does its export. The hooks are cleared after the export.
+Because the state of a constructor is rather delicate, the API prohibits you to just mess around with the whole constructor body at an expression level. For that to happen, you can register `onGenerate` hooks. These will be called when the corresponding `ClassBuilder` does its export. The hooks are cleared after the export.
+
+#  TypeMap
+
+You can find a type map, i.e. a map where the keys are `haxe.macro.Type`, in `tink.macro.TypeMap`. It's pretty much an ordinary map. Currently, it relies rather strongly on [`haxe.macro.TypeTools.toString()`](http://api.haxe.org/haxe/macro/TypeTools.html#toString) and it remains to be determined whether that is a reliable choice. Please report any issues you might face.

src/tink/macro/TypeMap.hx

@@ -0,0 +1,32 @@
+package tink.macro;
+
+import haxe.Constraints.IMap;
+import haxe.ds.BalancedTree;
+import haxe.macro.Context;
+import haxe.macro.Type;
+
+using haxe.macro.Tools;
+using tink.MacroApi;
+
+class TypeMap<V> extends BalancedTree<Type, V> implements IMap<Type, V> {
+  var follow:Bool;
+  
+  public function new(?noFollow:Bool) {
+    this.follow = noFollow != true;
+    super();
+  }
+  
+  override function compare(k1:Type, k2:Type):Int {
+    if (follow) {
+      k1 = k1.reduce();
+      k2 = k2.reduce();
+    }
+    //trace(k1.toString());
+    //trace(k2.toString());
+    return switch k1.getIndex() - k2.getIndex() {
+      case 0: Reflect.compare(k1.toString(), k2.toString());//TODO: this may be rather expensive and not very reliable
+      case v: v;
+    }
+  }
+  
+}

tests/Run.hx

@@ -11,6 +11,7 @@ class Run {
     new Exprs(),
     new Types(),
     new Positions(),
+    new TypeMapTest(),
   ];
   #end
   macro static function test() {

tests/TypeMapTest.hx

@@ -0,0 +1,30 @@
+package;
+
+import haxe.unit.TestCase;
+
+import tink.macro.TypeMap;
+using haxe.macro.Context;
+
+class TypeMapTest extends TestCase {
+
+  function testMap() {
+    var t = new TypeMap();
+    var t1 = (macro [{ foo: [{ bar: '5' }]}]).typeof();
+    var t2 = (macro [{ foo: [{ bar: 5 }]}]).typeof();
+    
+    t.set(t1, 0);
+    assertEquals(Lambda.count(t), 1);
+    t.set(t2, 1);
+    assertEquals(Lambda.count(t), 2);
+    t.set(t1, 2);
+    assertEquals(Lambda.count(t), 2);
+    t.set(t2, 3);
+    assertEquals(Lambda.count(t), 2);
+    
+    assertEquals(t.get(t1), 2);
+    assertEquals(t.get(t2), 3);
+    
+    assertTrue(true);
+  }
+  
+}