From d39df5314dba662a3fb587f98830c5a246623d16 Mon Sep 17 00:00:00 2001
From: Mitchell Plamann <mitchell.plamann@gmail.com>
Date: Sun, 19 Apr 2015 19:11:20 -0400
Subject: [PATCH] Fixed strings

---
 src/c0vm.js   | 19 +++++++++----------
 test/tests.js | 23 +++++++++++++++++------
 2 files changed, 26 insertions(+), 16 deletions(-)

diff --git a/src/c0vm.js b/src/c0vm.js
index 3bce00e..768964c 100755
--- a/src/c0vm.js
+++ b/src/c0vm.js
@@ -28,7 +28,6 @@ function i32_to_array(i32) {
             ((i32 >> 8) & 0xFF),
             ((i32 >> 16) & 0xFF),
             ((i32 >> 24) & 0xFF)];
-            
 }
 
 function array_to_i32(array) {
@@ -63,13 +62,13 @@ var ProgramState = function(parsed_file, callback_dict) {
         try {
             this.natives[i] = callback_dict[i];
         } catch (key_not_found) {
-            dict[i] = function (arg) { 
+            this.natives[i] = function (arg) {
                 console.log("Native function " + name + " called, ran method stub.");
                 return 0;
             };
         }
     }
-    
+
     // Memory is just a big array of bytes, right?
     // "Allocation" is appending onto this array
     // A pointer to memory is an index into this array.
@@ -138,7 +137,7 @@ ProgramState.prototype.step = function() {
     case op.BIPUSH:
         this.frame.pc += 2;
         var val = this.frame.program[this.frame.pc-1];
-        
+
         // Do sign extension if necessary
         if ((val & 0x80) != 0)
             val = -0x80 + (val & 0x7F);
@@ -340,9 +339,9 @@ ProgramState.prototype.step = function() {
             };
             console.log("Unknown native function index " + f.function_table_index);
         }
-        log("Calling native function with index " + index + " with arguments " + 
+        log("Calling native function with index " + index + " with arguments " +
             arg_array);
-        this.push(native_function(arg_array));
+        this.push(native_function(arg_array, this));
         break;
 
         // Memory allocation operations:
@@ -352,7 +351,7 @@ ProgramState.prototype.step = function() {
         var address = this.heap.length;
 
         for (var i = 0; i < size; i++) this.heap.push(0);
-        
+
         this.push(address);
         this.frame.pc += 2;
         break;
@@ -365,7 +364,7 @@ ProgramState.prototype.step = function() {
 
         this.heap.push(num_elements);
         this.heap.push(size);
-        
+
         for (var i = 0; i < num_elements; i++) {
             for (var j = 0; j < size; j++)
                 this.heap.push(0);
@@ -481,7 +480,7 @@ function execute(file, callbacks, v) {
     if (verbose) log(file);
 
     log("Beginning execution");
-    
+
     while (true) {
         var val = state.step();
         if (val !== undefined) return val;
@@ -500,7 +499,7 @@ function execute(file, callbacks, v) {
         //   save state (maybe in a global in this file?)
         //   return;
         // }
-    }        
+    }
 }
 
 exports.execute = execute;
diff --git a/test/tests.js b/test/tests.js
index 9d6a198..ad533a2 100644
--- a/test/tests.js
+++ b/test/tests.js
@@ -24,13 +24,25 @@ callbacks[c0ffi.NATIVE_STRING_LENGTH] = function(args) {
     return args[0].length;
 }
 
-callbacks[c0ffi.NATIVE_STRING_TO_CHARARRAY] = function(args) {
-    return args[0];
+callbacks[c0ffi.NATIVE_STRING_TO_CHARARRAY] = function(args, vm) {
+    var address = vm.heap.length;
+    vm.heap.push(args[0].length+1);
+    vm.heap.push(1);
+    for (var i = 0; i < args[0].length; i++) {
+        vm.heap.push(args[0][i]);
+    }
+    vm.heap.push(0);
+    return address;
 }
 
-callbacks[c0ffi.NATIVE_STRING_FROM_CHARARRAY] = function(args) {
-    console.log("string_from_chararray: " + args);
-    return args[0];
+callbacks[c0ffi.NATIVE_STRING_FROM_CHARARRAY] = function(args, vm) {
+    var i = args[0] + 2;
+    var result = "";
+    while (vm.heap[i] !== 0) {
+        result += vm.heap[i];
+        i++;
+    }
+    return result;
 }
 
 callbacks[c0ffi.NATIVE_CHAR_CHR] = function(args) {
@@ -38,7 +50,6 @@ callbacks[c0ffi.NATIVE_CHAR_CHR] = function(args) {
 }
 
 callbacks[c0ffi.NATIVE_CHAR_ORD] = function(args) {
-    console.log("native_car_ord: " + args);
     if (typeof args[0] == "string")
         return args[0].charCodeAt(0);
     return args[0];