updated code sample in the readme

README.md

@@ -21,25 +21,29 @@ Here's an example of a noja program that orders the items in list using a bubble
 ```
 L = [3, 2, 1];
 
-do {
+fun swap(a: int, b: int)
+    return b, a;
+
+fun order(L: List) {
+
+    do {
         swapped = false;
 
         i = 0;
         while i < count(L)-1 and not swapped: {
 
-        if L[i+1] < L[i]: {
+            swapped = L[i+1] < L[i];
+            if swapped:
+                L[i], L[i+1] = swap(L[i], L[i+1]);
             
-            swapped = true;
-            tmp = L[i+1];
-            L[i+1] = L[i];
-            L[i] = tmp;
+            i = i+1;
         }
+    } while swapped;
+}
 
-        i = i + 1;
-    }
-} while swapped;
-
-print(L, '\n'); # Outputs [1, 2, 3]
+print(L, '\n'); # [3, 2, 1]
+order(L);
+print(L, '\n'); # [1, 2, 3]
 ```
 
 ## Implementation Overview

examples/json/json.noja

@@ -1,21 +1,21 @@
 
-fun isSpace(c)
+fun isSpace(c: String)
     return c == " " or c == "\t" or c == "\n";
 
-fun isDigit(c) {
+fun isDigit(c: String) {
     u = unicode(c);
     d = u - unicode("0");
     return d >= 0 and d <= 9;
 }
 
-fun skipSpaces(context) {
+fun skipSpaces(context: Map) {
     # Skip zero or more whitespace characters.
     while context.cur < count(context.str) 
       and isSpace(context.str[context.cur]):
       context.cur = context.cur + 1;
 }
 
-fun parseNull(context) {
+fun parseNull(context: Map) {
     
     assert(context.cur < count(context) 
        and context.str[context.cur] == 'n');
@@ -30,7 +30,7 @@ fun parseNull(context) {
     return none;
 }
 
-fun parseTrue(context) {
+fun parseTrue(context: Map) {
     
     assert(context.cur < count(context) 
        and context.str[context.cur] == 't');
@@ -45,7 +45,7 @@ fun parseTrue(context) {
     return true;
 }
 
-fun parseFalse(context) {
+fun parseFalse(context: Map) {
     
     assert(context.cur < count(context) 
        and context.str[context.cur] == 'f');
@@ -61,14 +61,17 @@ fun parseFalse(context) {
     return false;
 }
 
-fun skip(context, test_callback) {
+fun dummy() {}
+Func = type(dummy);
+
+fun skip(context: Map, test_callback: Func) {
     k = context.cur;
     while k < count(context) and test_callback(context.str[k]):
         k = k + 1;
     return k;
 }
 
-fun parseInteger(context) {
+fun parseInteger(context: Map) {
     assert(context.cur < count(context) and isDigit(context.str[context.cur]));
 
     buffer = 0;
@@ -84,7 +87,7 @@ fun parseInteger(context) {
     return buffer;
 }
 
-fun parseFloating(context) {
+fun parseFloating(context: Map) {
     assert(context.cur < count(context) and isDigit(context.str[context.cur]));
 
     # It's ensured by the caller (parseIntegerOrFloating)
@@ -117,7 +120,7 @@ fun parseFloating(context) {
     return buffer;
 }
 
-fun parseIntegerOrFloating(context) {
+fun parseIntegerOrFloating(context: Map) {
     assert(context.cur < count(context) and isDigit(context.str[context.cur]));
 
     # Is the first digit sequence followed by a dot
@@ -132,7 +135,7 @@ fun parseIntegerOrFloating(context) {
         return parseInteger(context);
 }
 
-fun parseValue(context) {
+fun parseValue(context: Map) {
 
     if context.cur == count(context):
         return none, "Source ended where a value was expected";
@@ -159,7 +162,7 @@ fun parseValue(context) {
     return val, err;
 }
 
-fun parse(str) {
+fun parse(str: String) {
     context = {str: str, cur: 0};
     skipSpaces(context);
     val, err = parseValue(context);

src/lib/compiler/codegen.c

@@ -208,15 +208,24 @@ static void emitInstrForFuncCallNode(CodegenContext *ctx, CallExprNode *expr,
 static void emitInstrForArgumentNode(CodegenContext *ctx, ArgumentNode *arg, int argidx)
 {
 	/*
+	 *   // Push the type of the argument
 	 *   PUSHTYP;
-	 *   <arg-type-0> // What if this isn't a type?
+	 *   
+	 *   // Evaluate the type annotation and make
+	 *   // sure that it evaluated to a type.
+	 *   <arg-type-0>
 	 *   PUSHTYP;
 	 *   PUSHTYPTYP;
 	 *   EQL;
 	 *   JUMPIFANDPOP argument_annotation_0_not_type;
+     *
+	 *   // If the annotated type and the argument's
+	 *   // type match, jump to the argument assignment.
 	 *   EQL;
 	 *   JUMPIFANDPOP argument_type_ok;
 	 *
+	 *   // To the same for the next annotation.
+	 *
 	 *   PUSHTYP;
 	 *   <arg-type-1>
 	 *   PUSHTYP;
@@ -239,6 +248,9 @@ static void emitInstrForArgumentNode(CodegenContext *ctx, ArgumentNode *arg, int
 	 * argument_annotation_0_not_a_type:
 	 *   ERROR "Argument N annotation M isn't a type";
 	 * argument_type_ok:
+	 *
+	 *   // At this point we know that the argument has
+	 *   // a valid type.
 	 *   ASS <arg-name>;
 	 *   POP 1;
 	 */