diff -urN /Users/bpalmer/Programming/lua-5.1.2/src/lparser.c ./src/lparser.c
--- /Users/bpalmer/Programming/lua-5.1.2/src/lparser.c	2007-03-23 11:06:30.000000000 -0600
+++ ./src/lparser.c	2007-06-10 10:51:01.000000000 -0600
@@ -592,6 +592,27 @@
   pushclosure(ls, &new_fs, e);
 }
 
+static void body_lambda (LexState *ls, expdesc *e, int line) {
+  /* body_lambda ->  (`(' parlist `)' |) chunk ] */
+	/* omitting the `(` parlist `)` implies a vararg function */
+  FuncState new_fs;
+  open_func(ls, &new_fs);
+  new_fs.f->linedefined = line;
+	if (testnext(ls, '(')) {
+  	parlist(ls);
+  	checknext(ls, ')');
+	} else {
+		/* implied vararg */
+		new_fs.f->is_vararg |= VARARG_ISVARARG;
+		new_fs.f->numparams = cast_byte(new_fs.nactvar - (new_fs.f->is_vararg & VARARG_HASARG));
+	  luaK_reserveregs(&new_fs, new_fs.nactvar);  /* reserve register for parameters */
+	}
+  chunk(ls);
+  new_fs.f->lastlinedefined = ls->linenumber;
+  check_match(ls, ']', '[', line);
+  close_func(ls);
+  pushclosure(ls, &new_fs, e);
+}
 
 static int explist1 (LexState *ls, expdesc *v) {
   /* explist1 -> expr { `,' expr } */
@@ -761,6 +782,11 @@
       constructor(ls, v);
       return;
     }
+		case '[': {
+			luaX_next(ls);
+			body_lambda(ls, v, ls->linenumber);
+			return;
+		}
     case TK_FUNCTION: {
       luaX_next(ls);
       body(ls, v, 0, ls->linenumber);
@@ -871,7 +897,7 @@
 static int block_follow (int token) {
   switch (token) {
     case TK_ELSE: case TK_ELSEIF: case TK_END:
-    case TK_UNTIL: case TK_EOS:
+    case TK_UNTIL: case TK_EOS: case ']':
       return 1;
     default: return 0;
   }
@@ -1130,7 +1156,7 @@
   int condexit;
   luaX_next(ls);  /* skip IF or ELSEIF */
   condexit = cond(ls);
-  checknext(ls, TK_THEN);
+  testnext(ls, TK_THEN); /* THEN is optional */
   block(ls);  /* `then' part */
   return condexit;
 }
@@ -1303,7 +1329,7 @@
         localstat(ls);
       return 0;
     }
-    case TK_RETURN: {  /* stat -> retstat */
+    case TK_RETURN: case '|': {  /* stat -> retstat */
       retstat(ls);
       return 1;  /* must be last statement */
     }