type checks with (the [type] [value])

src/kiss/SpecialForms.hx

@@ -48,7 +48,16 @@ class SpecialForms {
 
         // TODO special form for switch
 
-        // TODO special form for try
+        // Type check syntax:
+        map["the"] = (args:Array<ReaderExp>, convert:ExprConversion) -> {
+            if (args.length != 2) {
+                throw '(the [type] [value]) expression has wrong number of arguments: ${args.length}';
+            }
+            ECheckType(convert(args[1]), switch (args[0]) {
+                case Symbol(type): Helpers.parseTypePath(type);
+                default: throw 'first argument to (the... ) should be a valid type';
+            }).withPos();
+        };
 
         map["try"] = (args:Array<ReaderExp>, convert:ExprConversion) -> {
             if (args.length == 0) {

src/test/cases/BasicTestCase.hx

@@ -137,4 +137,8 @@ class BasicTestCase extends Test {
         Assert.equals(6, BasicTestCase.myTryCatch(404));
         Assert.equals(7, BasicTestCase.myTryCatch(["list error"]));
     }
+
+    function testTypeCheck() {
+        Assert.equals(5, BasicTestCase.myTypeCheck());
+    }
 }

src/test/cases/BasicTestCase.kiss

@@ -83,3 +83,6 @@
         (catch [:String error] 5)
         (catch [:Int error] 6)
         (catch [error] 7)))
+
+(defun myTypeCheck []
+    (the Int 5))