Added Transformer class

Author: Willem Wyndham

.gitignore

@@ -3,4 +3,7 @@ docs/
 node_modules/
 out/
 raw/
-.history
+.history
+lib/visitor/dist/lib/
+
+lib/visitor/dist/src/

cli/asc.js

@@ -212,20 +212,27 @@ exports.main = function main(argv, options, callback) {
   // Set up transforms
   const transforms = [];
   if (args.transform) {
-    args.transform.forEach(transform =>
-      transforms.push(
-        require(
-          path.isAbsolute(transform = transform.trim())
-            ? transform
-            : path.join(process.cwd(), transform)
-        )
-      )
-    );
+    args.transform.forEach(transform => {
+      const transformer = require(path.isAbsolute(transform = transform.trim())
+                                  ? transform : path.join(process.cwd(), transform));
+                                  debugger;
+      if (transformer.default){
+        transforms.push(transformer.default);
+      } else {
+        throw new Error("Transformer must have a default export.");
+      }
+    });
   }
   function applyTransform(name, ...args) {
     transforms.forEach(transform => {
       try {
-        if (typeof transform[name] === "function") transform[name](...args);
+        if (typeof transform === "function") {
+          const transformer = new transform(...args);
+          if (typeof transformer[name] !== "function") {
+            throw new Error("Transformer missing " + name + " method.");
+          }
+          transformer[name]();
+        }
       } catch (e) {
         callback(e);
       }
@@ -430,7 +437,7 @@ exports.main = function main(argv, options, callback) {
   }
 
   // Call afterParse transform hook
-  applyTransform("afterParse", parser, writeFile, baseDir);
+  applyTransform("afterParse", parser, writeFile, baseDir, writeStdout);
 
   // Parse additional files, if any
   {

lib/visitor/README.md

@@ -1,9 +1,6 @@
-# Near Bindings
+# AST Transformer
 
-This AST transformer is added to the compiler fontend so that it is called automatically after all files have been parsed.
+After parsing the files imported by the entry files, the Abstract Syntax Tree (AST) is made.  With the `--transform` argument, the compiler will load any js files provided and if the exports include a Transformer class.
 
-Any file that has `//@nearfile` as the first line, will be processed and a new source text will be generated.
+# Transformer class
 
-Currently any class defined in the file will have an `encode` and `decode` method for serializing to and from json.  Furthermore, any functions that are exported by an entry function are wrapped so that their arguments are deserialized from storage and its return value is serailazed.
-
-Furthermore `./src/preamble.ts` defines a string that can be added to the top of the source file.  After each file is processed the new source text is parsed.  This means any new imports added in the preamble will be parsed too.