diff --git a/bin/main.c b/bin/main.c
index d547c6e..881182a 100644
--- a/bin/main.c
+++ b/bin/main.c
@@ -96,6 +96,9 @@ struct xtn_t
 	/*hcl_oop_t sym_errstr;*/
 };
 
+/* ========================================================================= */
+
+static hcl_t* g_hcl = HCL_NULL;
 
 /* ========================================================================= */
 
@@ -426,12 +429,91 @@ static void vm_checkbc (hcl_t* hcl, hcl_oob_t bcode)
 }
 */
 
+
 static void gc_hcl (hcl_t* hcl)
 {
 	xtn_t* xtn = (xtn_t*)hcl_getxtn(hcl);
 	/*if (xtn->sym_errstr) xtn->sym_errstr = hcl_moveoop(hcl, xtn->sym_errstr);*/
 }
 
+/* ========================================================================= */
+
+static hcl_oop_t execute_in_interactive_mode (hcl_t* hcl)
+{
+	hcl_oop_t retv;
+
+	hcl_decode (hcl, 0, hcl_getbclen(hcl));
+	HCL_LOG0 (hcl, HCL_LOG_MNEMONIC, "------------------------------------------\n");
+	g_hcl = hcl;
+	/*setup_tick ();*/
+
+	retv = hcl_execute(hcl);
+
+	/* flush pending output data in the interactive mode(e.g. printf without a newline) */
+	hcl_flushio (hcl);
+
+	if (!retv)
+	{
+		hcl_logbfmt (hcl, HCL_LOG_STDERR, "ERROR: cannot execute - [%d] %js\n", hcl_geterrnum(hcl), hcl_geterrmsg(hcl));
+	}
+	else
+	{
+		/* print the result in the interactive mode regardless 'verbose' */
+		hcl_logbfmt (hcl, HCL_LOG_STDOUT, "%O\n", retv); /* TODO: show this go to the output handler?? */
+		/*
+		 * print the value of ERRSTR.
+		hcl_oop_cons_t cons = hcl_getatsysdic(hcl, xtn->sym_errstr);
+		if (cons)
+		{
+			HCL_ASSERT (hcl, HCL_IS_CONS(hcl, cons));
+			HCL_ASSERT (hcl, HCL_CONS_CAR(cons) == xtn->sym_errstr);
+			hcl_print (hcl, HCL_CONS_CDR(cons));
+		}
+		*/
+	}
+	/*cancel_tick();*/
+	g_hcl = HCL_NULL;
+
+	return retv;
+}
+
+
+static hcl_oop_t execute_in_batch_mode (hcl_t* hcl, int verbose)
+{
+	hcl_oop_t retv;
+
+	hcl_decode (hcl, 0, hcl_getbclen(hcl));
+	HCL_LOG2 (hcl, HCL_LOG_MNEMONIC, "BYTECODES bclen = > %zu lflen => %zu\n", hcl_getbclen(hcl), hcl_getlflen(hcl));
+	g_hcl = hcl;
+	/*setup_tick ();*/
+
+	retv = hcl_execute(hcl);
+	hcl_flushio (hcl);
+
+	if (!retv)
+	{
+		hcl_logbfmt (hcl, HCL_LOG_STDERR, "ERROR: cannot execute - [%d] %js\n", hcl_geterrnum(hcl), hcl_geterrmsg(hcl));
+	}
+	else if (verbose)
+	{
+		hcl_logbfmt (hcl, HCL_LOG_STDERR, "EXECUTION OK - EXITED WITH %O\n", retv);
+	}
+
+	/*cancel_tick();*/
+	g_hcl = HCL_NULL;
+	/*hcl_dumpsymtab (hcl);*/
+
+	return retv;
+}
+
+static int on_fed_cnode_in_interactive_mode (hcl_t* hcl, hcl_cnode_t* obj)
+{
+	if (hcl_compile(hcl, obj, HCL_COMPILE_CLEAR_CODE | HCL_COMPILE_CLEAR_FNBLK) <= -1) return -1;
+	execute_in_interactive_mode (hcl);
+	return 0;
+}
+
+
 /* ========================================================================= */
 
 static int handle_logopt (hcl_t* hcl, const hcl_bch_t* logstr)
@@ -565,12 +647,6 @@ static int handle_dbgopt (hcl_t* hcl, const hcl_bch_t* str)
 	return 0;
 }
 #endif
-/* ========================================================================= */
-
-static hcl_t* g_hcl = HCL_NULL;
-
-/* ========================================================================= */
-
 
 /* ========================================================================= */
 
@@ -704,7 +780,7 @@ count++;
 				print_synerr (hcl);
 				if (xtn->reader_istty && hcl_getsynerrnum(hcl) != HCL_SYNERR_EOF)
 				{
-					/* TODO: drain remaining data in the reader including the actual inputstream and buffered data in hcl */
+					/* TODO: drain remaining data in the reader including the actual input stream and buffered data in hcl */
 					continue;
 				}
 			}
@@ -736,66 +812,11 @@ count++;
 		else if (xtn->reader_istty)
 		{
 			/* interactive mode */
-			hcl_oop_t retv;
-
-			hcl_decode (hcl, 0, hcl_getbclen(hcl));
-			HCL_LOG0 (hcl, HCL_LOG_MNEMONIC, "------------------------------------------\n");
-			g_hcl = hcl;
-			/*setup_tick ();*/
-
-			retv = hcl_execute(hcl);
-
-			/* flush pending output data in the interactive mode(e.g. printf without a newline) */
-			hcl_flushio (hcl);
-
-			if (!retv)
-			{
-				hcl_logbfmt (hcl, HCL_LOG_STDERR, "ERROR: cannot execute - [%d] %js\n", hcl_geterrnum(hcl), hcl_geterrmsg(hcl));
-			}
-			else
-			{
-				/* print the result in the interactive mode regardless 'verbose' */
-				hcl_logbfmt (hcl, HCL_LOG_STDOUT, "%O\n", retv); /* TODO: show this go to the output handler?? */
-
-				/*
-				 * print the value of ERRSTR.
-				hcl_oop_cons_t cons = hcl_getatsysdic(hcl, xtn->sym_errstr);
-				if (cons)
-				{
-					HCL_ASSERT (hcl, HCL_IS_CONS(hcl, cons));
-					HCL_ASSERT (hcl, HCL_CONS_CAR(cons) == xtn->sym_errstr);
-					hcl_print (hcl, HCL_CONS_CDR(cons));
-				}
-				*/
-			}
-			/*cancel_tick();*/
-			g_hcl = HCL_NULL;
+			execute_in_interactive_mode (hcl);
 		}
 	}
 
-	if (!xtn->reader_istty && hcl_getbclen(hcl) > 0)
-	{
-		hcl_oop_t retv;
-
-		hcl_decode (hcl, 0, hcl_getbclen(hcl));
-		HCL_LOG2 (hcl, HCL_LOG_MNEMONIC, "BYTECODES bclen = > %zu lflen => %zu\n", hcl_getbclen(hcl), hcl_getlflen(hcl));
-		g_hcl = hcl;
-		/*setup_tick ();*/
-
-		retv = hcl_execute(hcl);
-		if (!retv)
-		{
-			hcl_logbfmt (hcl, HCL_LOG_STDERR, "ERROR: cannot execute - [%d] %js\n", hcl_geterrnum(hcl), hcl_geterrmsg(hcl));
-		}
-		else if (verbose)
-		{
-			hcl_logbfmt (hcl, HCL_LOG_STDERR, "EXECUTION OK - EXITED WITH %O\n", retv);
-		}
-
-		/*cancel_tick();*/
-		g_hcl = HCL_NULL;
-		/*hcl_dumpsymtab (hcl);*/
-	}
+	if (!xtn->reader_istty && hcl_getbclen(hcl) > 0) execute_in_batch_mode (hcl, verbose);
 
 	return 0;
 
@@ -822,7 +843,10 @@ static int feed_loop (hcl_t* hcl, xtn_t* xtn, int cflags, int verbose)
 	}
 
 	/*(setvbuf (fp, NULL, _IONBF, 0);*/
+	
+	if (xtn->reader_istty) hcl_beginfeed (hcl, on_fed_cnode_in_interactive_mode); /* override the default cnode handler */
 
+/* TODO: use the io handler attached .. */
 	while (1)
 	{
 		hcl_ooi_t n;
@@ -854,7 +878,6 @@ static int feed_loop (hcl_t* hcl, xtn_t* xtn, int cflags, int verbose)
 			/* 'len' must remain 0 in this case */
 		#endif
 
-	/* the compiler must be invoked whenever feed() sees a complete object */
 			if (x <= -1) goto feed_error;
 		}
 
@@ -884,11 +907,7 @@ static int feed_loop (hcl_t* hcl, xtn_t* xtn, int cflags, int verbose)
 
 	fclose (fp);
 
-/* TODO: execute code? */
-	if (hcl_getbclen(hcl) > 0)
-	{
-/* TODO: execute code... */
-	}
+	if (!xtn->reader_istty && hcl_getbclen(hcl) > 0) execute_in_batch_mode (hcl, verbose);
 
 	return 0;
 
@@ -1025,7 +1044,7 @@ int main (int argc, char* argv[])
 
 	memset (&hclcb, 0, HCL_SIZEOF(hclcb));
 	hclcb.gc = gc_hcl;
-	hclcb.vm_startup =  vm_startup;
+	hclcb.vm_startup = vm_startup;
 	hclcb.vm_cleanup = vm_cleanup;
 	/*hclcb.vm_checkbc = vm_checkbc;*/
 	hcl_regcb (hcl, &hclcb);
diff --git a/lib/hcl-prv.h b/lib/hcl-prv.h
index 390c3b6..b4caf32 100644
--- a/lib/hcl-prv.h
+++ b/lib/hcl-prv.h
@@ -702,17 +702,8 @@ struct hcl_compiler_t
 			} u;
 		} lx;
 
-		struct
-		{
-			int code;
-			/*union
-			{
-				
-			} u;*/
-		} st[100];
-		hcl_ooi_t top;
-
 		struct hcl_frd_t rd;
+		hcl_on_cnode_t on_cnode;
 	} feed;
 
 	/* == COMPILER STACK == */
diff --git a/lib/hcl.h b/lib/hcl.h
index 441f3f7..555139c 100644
--- a/lib/hcl.h
+++ b/lib/hcl.h
@@ -1459,6 +1459,8 @@ struct hcl_dbgi_t
 typedef struct hcl_compiler_t hcl_compiler_t;
 typedef struct hcl_cnode_t hcl_cnode_t;
 
+typedef int (*hcl_on_cnode_t) (hcl_t* hcl, hcl_cnode_t* obj);
+
 enum hcl_compile_flag_t
 {
 	/* clear byte codes at the beginnign of hcl_compile() */
@@ -2082,7 +2084,6 @@ HCL_EXPORT int hcl_setoption (
 	const void*   value
 );
 
-
 HCL_EXPORT hcl_cb_t* hcl_regcb (
 	hcl_t*    hcl,
 	hcl_cb_t* tmpl
@@ -2151,9 +2152,9 @@ HCL_EXPORT void hcl_abort (
 
 
 HCL_EXPORT int hcl_attachio (
-	hcl_t*       hcl,
-	hcl_ioimpl_t reader,
-	hcl_ioimpl_t printer
+	hcl_t*         hcl,
+	hcl_ioimpl_t   reader,
+	hcl_ioimpl_t   printer
 );
 
 HCL_EXPORT void hcl_detachio (
@@ -2168,11 +2169,6 @@ HCL_EXPORT hcl_cnode_t* hcl_read (
 	hcl_t*       hcl
 );
 
-HCL_EXPORT void hcl_freecnode (
-	hcl_t*       hcl,
-	hcl_cnode_t* cnode
-);
-
 HCL_EXPORT int hcl_print (
 	hcl_t*       hcl,
 	hcl_oop_t    obj
@@ -2194,6 +2190,16 @@ HCL_EXPORT hcl_ooi_t hcl_proutufmt (
 
 #if defined(HCL_INCLUDE_COMPILER)
 
+HCL_EXPORT void hcl_freecnode (
+	hcl_t*       hcl,
+	hcl_cnode_t* cnode
+);
+
+HCL_EXPORT void hcl_beginfeed (
+	hcl_t*            hcl,
+	hcl_on_cnode_t    on_cnode
+);
+
 HCL_EXPORT int hcl_feed (
 	hcl_t*            hcl,
 	const hcl_ooch_t* data,
diff --git a/lib/read.c b/lib/read.c
index ba56115..8918706 100644
--- a/lib/read.c
+++ b/lib/read.c
@@ -2247,6 +2247,14 @@ hcl_cnodetoobj (hcl_t* hcl, hcl_cnode_t* x)
 
 /* ---------------------------------------------------------------------- */
 
+static int on_fed_cnode (hcl_t* hcl, hcl_cnode_t* obj)
+{
+	/* the default handler for a cnode composed via feeding - just compile the object node. */
+	return hcl_compile(hcl, obj, 0);
+}
+
+/* ---------------------------------------------------------------------- */
+
 static void init_feed (hcl_t* hcl)
 {
 	HCL_MEMSET (&hcl->c->feed, 0, HCL_SIZEOF(hcl->c->feed));
@@ -2256,31 +2264,11 @@ static void init_feed (hcl_t* hcl)
 	hcl->c->feed.lx.loc.colm = 1;
 	hcl->c->feed.lx.loc.file = HCL_NULL;
 
-	hcl->c->feed.top = -1;
+	hcl->c->feed.on_cnode = on_fed_cnode;
 }
 
 /* ------------------------------------------------------------------------ */
 
-static int fst_push (hcl_t* hcl, int code)
-{
-	if (hcl->c->feed.top >= HCL_COUNTOF(hcl->c->feed.st) - 1) /* TODO: use a dynamically allocated stack? */
-	{
-		hcl_seterrbfmt (hcl, HCL_EBUFFULL, "feed stack full"); 
-		return -1;
-	}
-
-	hcl->c->feed.top++;
-	HCL_MEMSET (&hcl->c->feed.st[hcl->c->feed.top], 0, HCL_SIZEOF(hcl->c->feed.st[hcl->c->feed.top]));
-	hcl->c->feed.st[hcl->c->feed.top].code = code;
-	return 0;
-}
-
-static void fst_pop (hcl_t* hcl)
-{
-	HCL_ASSERT (hcl, hcl->c->feed.top >= 0);
-	hcl->c->feed.top--;
-}
-
 static int feed_begin_include (hcl_t* hcl)
 {
 	hcl_ioinarg_t* arg;
@@ -2327,11 +2315,9 @@ static int feed_end_include (hcl_t* hcl)
 
 	x = hcl->c->reader(hcl, HCL_IO_CLOSE, hcl->c->curinp);
 
-	/* if closing has failed, still destroy the
-	 * sio structure first as normal and return
-	 * the failure below. this way, the caller
-	 * does not call HCL_IO_CLOSE on
-	 * hcl->c->curinp again. */
+	/* if closing has failed, still destroy the sio structure 
+	 * first as normal and return the failure below. this way, 
+	 * the caller doesn't call HCL_IO_CLOSE on hcl->c->curinp again. */
 
 	cur = hcl->c->curinp;
 	hcl->c->curinp = hcl->c->curinp->includer;
@@ -2683,7 +2669,8 @@ static int feed_process_token (hcl_t* hcl)
 	/* check if we are at the top frd->level */
 	if (frd->level <= 0) 
 	{
-		// TOOD: callback with frd->obj in case it's complete
+		int n;
+		hcl_cb_t* cb;
 
 		/* upon exit, we must be at the top level */
 		HCL_ASSERT (hcl, frd->level == 0);
@@ -2692,14 +2679,10 @@ static int feed_process_token (hcl_t* hcl)
 		HCL_ASSERT (hcl, hcl->c->r.st == HCL_NULL);
 		HCL_ASSERT (hcl, frd->obj != HCL_NULL);
 
-/* TODO: error handling, etc */
-hcl_compile(hcl, frd->obj, HCL_COMPILE_CLEAR_CODE | HCL_COMPILE_CLEAR_FNBLK); /* flags 0 if non-interactive */
-hcl_freecnode (hcl, frd->obj); /* not needed any more */
-frd->obj = HCL_NULL;
-hcl_decode (hcl, 0, hcl_getbclen(hcl));
-hcl_execute (hcl);
-hcl_flushio (hcl);
-
+		n = hcl->c->feed.on_cnode(hcl, frd->obj);
+		hcl_freecnode (hcl, frd->obj); /* not needed any more */
+		frd->obj = HCL_NULL;
+		if (n <= -1) goto oops;
 	}
 	else
 	{
@@ -2715,7 +2698,6 @@ hcl_flushio (hcl);
 		clear_comma_colon_flag (hcl);
 	}
 
-
 ok:
 	return 0;
 
@@ -2949,16 +2931,10 @@ static int flx_start (hcl_t* hcl, hcl_ooci_t c)
 	switch (c)
 	{
 		case HCL_OOCI_EOF:
-		{
-			int n;
-#if 0
-			n = end_include(hcl);
-			if (n <= -1) return -1;
-			if (n >= 1) goto retry;
-#endif
+			/* only EOF of the top-level stream is supposed to be fed in.
+			 * the internal logic discard EOFs of included streams */
 			FEED_WRAP_UP_WITH_CHARS (hcl, vocas[VOCA_EOF].str, vocas[VOCA_EOF].len, HCL_IOTOK_EOF);
 			goto consumed;
-		}
 
 		case ';':
 			FEED_CONTINUE_WITH_CHAR (hcl, c, HCL_FLX_COMMENT);
@@ -3706,7 +3682,6 @@ static int feed_char (hcl_t* hcl, hcl_ooci_t c)
 static int feed_from_included (hcl_t* hcl)
 {
 	int x;
-	hcl_ooch_t lc;
 
 	HCL_ASSERT (hcl, hcl->c->curinp != HCL_NULL && hcl->c->curinp != &hcl->c->inarg);
 
@@ -3721,7 +3696,7 @@ static int feed_from_included (hcl_t* hcl)
 
 			if (hcl->c->curinp->xlen <= 0)
 			{
-				/* got EOF */
+				/* got EOF from an included stream */
 				#if 0
 				x = feed_char(hcl, HCL_OOCI_EOF); /* TODO: or call feed_end_include? */
 				if (x <= -1) return -1;
@@ -3735,17 +3710,18 @@ static int feed_from_included (hcl_t* hcl)
 			hcl->c->curinp->b.len = hcl->c->curinp->xlen;
 		}
 
-		lc = hcl->c->curinp->buf[hcl->c->curinp->b.pos];
-		x = feed_char(hcl, lc);
+		x = feed_char(hcl, hcl->c->curinp->buf[hcl->c->curinp->b.pos]);
 		if (x <= -1) return -1;
 		hcl->c->curinp->b.pos += x;
 
 		if (hcl->c->feed.rd.do_include_file)
 		{
-			/* perform delayed file inclusion. the token buffer must remain unchanged 
-			 * since do_include_file has been set to true in feed_process_token(). */
+			/* feed_process_token(), called for the "filename" token for the #include 
+			 * directive, sets hcl->c->feed.rd.do_include_file to 1 instead of attepmting
+			 * to include the file. the file inclusion is attempted here after the return
+			 * value of feed_char() is used to advance the hcl->c->curinp->b.pos pointer. */
+			hcl->c->feed.rd.do_include_file = 0; /* clear this regardless of inclusion result */
 			if (feed_begin_include(hcl) <= -1) return -1;
-			hcl->c->feed.rd.do_include_file = 0;
 		}
 	}
 	while (hcl->c->curinp != &hcl->c->inarg);
@@ -3753,6 +3729,11 @@ static int feed_from_included (hcl_t* hcl)
 	return 0;
 }
 
+void hcl_beginfeed (hcl_t* hcl, hcl_on_cnode_t on_cnode)
+{
+	hcl->c->feed.on_cnode = on_cnode;
+}
+
 int hcl_feed (hcl_t* hcl, const hcl_ooch_t* data, hcl_oow_t len)
 {
 /* TODO: need to return the number of processed characters?
@@ -3761,6 +3742,7 @@ int hcl_feed (hcl_t* hcl, const hcl_ooch_t* data, hcl_oow_t len)
 	hcl_oow_t i;
 	int x;
 
+
 	if (data) 
 	{
 		for (i = 0; i < len; ) 
@@ -3800,10 +3782,23 @@ int hcl_feed (hcl_t* hcl, const hcl_ooch_t* data, hcl_oow_t len)
 	}
 	else
 	{
-		for (i = 0; i < 1;)
+		for (i = 0; i < 1;) /* weird loop in case feed_char() returns 0 */
 		{
 			x = feed_char(hcl, HCL_OOCI_EOF);
-			if (x <= -1) return -1;
+			if (x <= -1) 
+			{
+				if (hcl->c->feed.rd.level <= 0 && hcl_geterrnum(hcl) == HCL_ESYNERR && hcl_getsynerrnum(hcl) == HCL_SYNERR_EOF)
+				{
+					/* convert this EOF error to success as the caller knows EOF in the feed mode. 
+					 * the caller can safely stop feeding after gettting success from hcl_feed(hcl, HCL_NULL, 0); 
+					 * in the feed mode, this function doesn't set HCL_EFINIS. */
+					x = 1;
+				}
+				else
+				{
+					return -1;
+				}
+			}
 			i += x;
 		}
 	}