diff --git a/bin/main.c b/bin/main.c
index 79b05cc..352c8f7 100644
--- a/bin/main.c
+++ b/bin/main.c
@@ -362,7 +362,7 @@ static void print_synerr (hcl_t* hcl)
 	hcl_synerr_t synerr;
 	xtn_t* xtn;
 
-	xtn = (xtn_t*)hcl_getxtn (hcl);
+	xtn = (xtn_t*)hcl_getxtn(hcl);
 	hcl_getsynerr (hcl, &synerr);
 
 	hcl_logbfmt (hcl,HCL_LOG_STDERR, "ERROR: ");
diff --git a/lib/comp.c b/lib/comp.c
index 875348f..0d6b972 100644
--- a/lib/comp.c
+++ b/lib/comp.c
@@ -112,7 +112,7 @@ static int copy_string_to (hcl_t* hcl, const hcl_oocs_t* src, hcl_oocs_t* dst, h
 		if (HCL_UNLIKELY(!tmp))
 		{
 			const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-			hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to grow string buffer - %js", orgmsg);
+			hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to grow string buffer - %js", orgmsg);
 			return -1;
 		}
 
@@ -535,7 +535,7 @@ static int emit_byte_instruction (hcl_t* hcl, hcl_oob_t bc, const hcl_loc_t* src
 		if (HCL_UNLIKELY(!tmp))
 		{
 			const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-			hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to grow byte code buffer - %js", orgmsg);
+			hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to grow byte code buffer - %js", orgmsg);
 			return -1;
 		}
 
@@ -543,7 +543,7 @@ static int emit_byte_instruction (hcl_t* hcl, hcl_oob_t bc, const hcl_loc_t* src
 		if (HCL_UNLIKELY(!tmp2))
 		{
 			const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-			hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to grow debug info buffer - %js", orgmsg);
+			hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to grow debug info buffer - %js", orgmsg);
 			hcl_freemem (hcl, tmp);
 			return -1;
 		}
@@ -969,7 +969,7 @@ static int push_cblk (hcl_t* hcl, const hcl_loc_t* errloc, hcl_cblk_type_t type)
 		if (HCL_UNLIKELY(!tmp))
 		{
 			const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-			hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to resize control block info buffer - %js", orgmsg);
+			hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to resize control block info buffer - %js", orgmsg);
 			return -1;
 		}
 
@@ -1019,7 +1019,7 @@ static int push_clsblk (hcl_t* hcl, const hcl_loc_t* errloc, hcl_oow_t nivars, h
 		if (HCL_UNLIKELY(!tmp))
 		{
 			const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-			hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to resize class block info buffer - %js", orgmsg);
+			hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to resize class block info buffer - %js", orgmsg);
 			return -1;
 		}
 
@@ -1123,7 +1123,7 @@ static int push_fnblk (hcl_t* hcl, const hcl_loc_t* errloc,
 		if (HCL_UNLIKELY(!tmp))
 		{
 			const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-			hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to resize function block info buffer - %js", orgmsg);
+			hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to resize function block info buffer - %js", orgmsg);
 			return -1;
 		}
 
@@ -1239,7 +1239,7 @@ static HCL_INLINE int _insert_cframe (hcl_t* hcl, hcl_ooi_t index, int opcode, h
 		if (HCL_UNLIKELY(!tmp))
 		{
 			const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-			hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to grow compiler frame stack- %js", orgmsg);
+			hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to grow compiler frame stack- %js", orgmsg);
 			hcl->c->cfs.top--;
 			return -1;
 		}
diff --git a/lib/err.c b/lib/err.c
index 34c2500..bd6f256 100644
--- a/lib/err.c
+++ b/lib/err.c
@@ -179,6 +179,12 @@ static hcl_uch_t e_unknown_u[] = {'u','n','k','n','o','w','n',' ','e','r','r','o
 #	define e_unknown e_unknown_u
 #endif
 
+
+int hcl_errnum_is_synerr (hcl_errnum_t errnum)
+{
+	return errnum == HCL_ESYNERR;
+}
+
 const hcl_ooch_t* hcl_errnum_to_errstr (hcl_errnum_t errnum)
 {
 	return (errnum >= 0 && errnum < HCL_COUNTOF(errstr))? errstr[errnum]: e_unknown;
@@ -268,6 +274,11 @@ const hcl_ooch_t* hcl_backuperrmsg (hcl_t* hcl)
 	return hcl->errmsg.tmpbuf.ooch;
 }
 
+hcl_errnum_t hcl_geterrnum (hcl_t* hcl)
+{
+	return HCL_ERRNUM(hcl);
+}
+
 void hcl_seterrnum (hcl_t* hcl, hcl_errnum_t errnum)
 {
 	if (hcl->shuterr) return;
diff --git a/lib/exec.c b/lib/exec.c
index 14575bd..856c5e0 100644
--- a/lib/exec.c
+++ b/lib/exec.c
@@ -2367,7 +2367,7 @@ static void supplement_errmsg (hcl_t* hcl, hcl_ooi_t ip)
 	{
 		hcl_dbgi_t* dbgi;
 		const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-		hcl_errnum_t orgnum = hcl_geterrnum(hcl);
+		hcl_errnum_t orgnum = HCL_ERRNUM(hcl);
 
 		HCL_ASSERT (hcl, HCL_IS_BYTEARRAY(hcl, hcl->active_function->dbgi));
 		dbgi = (hcl_dbgi_t*)HCL_OBJ_GET_BYTE_SLOT(hcl->active_function->dbgi);
diff --git a/lib/hcl-s.c b/lib/hcl-s.c
index 1f0c6fa..eca7320 100644
--- a/lib/hcl-s.c
+++ b/lib/hcl-s.c
@@ -1292,7 +1292,7 @@ static void reformat_synerr (hcl_t* hcl)
 
 static void send_proto_hcl_error (hcl_server_proto_t* proto)
 {
-	if (hcl_geterrnum(proto->hcl) == HCL_ESYNERR) reformat_synerr (proto->hcl);
+	if (HCL_ERRNUM(proto->hcl) == HCL_ESYNERR) reformat_synerr (proto->hcl);
 	send_error_message (proto, hcl_geterrmsg(proto->hcl));
 }
 
diff --git a/lib/hcl-s2.c b/lib/hcl-s2.c
index 5e301df..75e1204 100644
--- a/lib/hcl-s2.c
+++ b/lib/hcl-s2.c
@@ -1367,7 +1367,7 @@ static void reformat_synerr (hcl_t* hcl)
 
 static void send_proto_hcl_error (hcl_server_proto_t* proto)
 {
-	if (hcl_geterrnum(proto->hcl) == HCL_ESYNERR) reformat_synerr (proto->hcl);
+	if (HCL_ERRNUM(proto->hcl) == HCL_ESYNERR) reformat_synerr (proto->hcl);
 	send_error_message (proto, hcl_geterrmsg(proto->hcl));
 }
 
diff --git a/lib/hcl.c b/lib/hcl.c
index 0bed1b3..9f564bc 100644
--- a/lib/hcl.c
+++ b/lib/hcl.c
@@ -830,7 +830,7 @@ hcl_mod_data_t* hcl_openmod (hcl_t* hcl, const hcl_ooch_t* name, hcl_oow_t namel
 	load = (hcl_mod_load_t)hcl->vmprim.dl_getsym(hcl, md.handle, buf);
 	if (!load)
 	{
-		hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "unable to get module symbol [%js] in [%.*js]", buf, namelen, name);
+		hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "unable to get module symbol [%js] in [%.*js]", buf, namelen, name);
 		HCL_DEBUG3 (hcl, "Cannot get a module symbol [%js] in [%.*js]\n", buf, namelen, name);
 		hcl->vmprim.dl_close (hcl, md.handle);
 		return HCL_NULL;
@@ -851,7 +851,7 @@ hcl_mod_data_t* hcl_openmod (hcl_t* hcl, const hcl_ooch_t* name, hcl_oow_t namel
 	if (load(hcl, &mdp->mod) <= -1)
 	{
 		const hcl_ooch_t* oldmsg = hcl_backuperrmsg (hcl);
-		hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "module initializer [%js] returned failure in [%.*js] - %js", buf, namelen, name, oldmsg);
+		hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "module initializer [%js] returned failure in [%.*js] - %js", buf, namelen, name, oldmsg);
 		HCL_DEBUG3 (hcl, "Module function [%js] returned failure in [%.*js]\n", buf, namelen, name);
 		hcl_rbt_delete (&hcl->modtab, name, namelen);
 		hcl->vmprim.dl_close (hcl, mdp->handle);
diff --git a/lib/hcl.h b/lib/hcl.h
index 26b2cad..eb2b5cf 100644
--- a/lib/hcl.h
+++ b/lib/hcl.h
@@ -2037,15 +2037,19 @@ static HCL_INLINE void* hcl_getxtn (hcl_t* hcl) { return (void*)((hcl_uint8_t*)h
 static HCL_INLINE hcl_mmgr_t* hcl_getmmgr (hcl_t* hcl) { return hcl->_mmgr; }
 static HCL_INLINE hcl_cmgr_t* hcl_getcmgr (hcl_t* hcl) { return hcl->_cmgr; }
 static HCL_INLINE void hcl_setcmgr (hcl_t* hcl, hcl_cmgr_t* cmgr) { hcl->_cmgr = cmgr; }
-static HCL_INLINE hcl_errnum_t hcl_geterrnum (hcl_t* hcl) { return hcl->errnum; }
 #else
 #	define hcl_getxtn(hcl) ((void*)((hcl_uint8_t*)hcl + ((hcl_t*)hcl)->_instsize))
 #	define hcl_getmmgr(hcl) (((hcl_t*)(hcl))->_mmgr)
 #	define hcl_getcmgr(hcl) (((hcl_t*)(hcl))->_cmgr)
 #	define hcl_setcmgr(hcl,cmgr) (((hcl_t*)(hcl))->_cmgr = (cmgr))
-#	define hcl_geterrnum(hcl) (((hcl_t*)(hcl))->errnum)
 #endif
 
+#define HCL_ERRNUM(hcl) (((hcl_t*)(hcl))->errnum)
+
+HCL_EXPORT hcl_errnum_t hcl_geterrnum (
+	hcl_t* hcl
+);
+
 HCL_EXPORT void hcl_seterrnum (
 	hcl_t*       hcl,
 	hcl_errnum_t errnum
@@ -2137,6 +2141,10 @@ HCL_EXPORT const hcl_ooch_t* hcl_backuperrmsg (
 	hcl_t* hcl
 );
 
+HCL_EXPORT int hcl_errnum_is_synerr (
+	hcl_errnum_t errnum
+);
+
 HCL_EXPORT const hcl_ooch_t* hcl_errnum_to_errstr (
 	hcl_errnum_t errnum
 );
@@ -2443,7 +2451,7 @@ HCL_EXPORT hcl_synerrnum_t hcl_getsynerrnum (
 HCL_EXPORT void hcl_setsynerrbfmt (
 	hcl_t*              hcl,
 	hcl_synerrnum_t     num,
-	const hcl_loc_t*  loc,
+	const hcl_loc_t*    loc,
 	const hcl_oocs_t*   tgt,
 	const hcl_bch_t*    msgfmt,
 	...
@@ -2452,17 +2460,17 @@ HCL_EXPORT void hcl_setsynerrbfmt (
 HCL_EXPORT void hcl_setsynerrufmt (
 	hcl_t*              hcl,
 	hcl_synerrnum_t     num,
-	const hcl_loc_t*  loc,
+	const hcl_loc_t*    loc,
 	const hcl_oocs_t*   tgt,
 	const hcl_uch_t*    msgfmt,
 	...
 );
 
 #if defined(HCL_HAVE_INLINE)
-	static HCL_INLINE void hcl_setsynerr (hcl_t* hcl, hcl_synerrnum_t num, const hcl_loc_t* loc, const hcl_oocs_t* tgt)
-	{
-		hcl_setsynerrbfmt (hcl, num, loc, tgt, HCL_NULL);
-	}
+static HCL_INLINE void hcl_setsynerr (hcl_t* hcl, hcl_synerrnum_t num, const hcl_loc_t* loc, const hcl_oocs_t* tgt)
+{
+	hcl_setsynerrbfmt (hcl, num, loc, tgt, HCL_NULL);
+}
 #else
 #	define hcl_setsynerr(hcl,num,loc,tgt) hcl_setsynerrbfmt(hcl,num,loc,tgt,HCL_NULL)
 #endif
diff --git a/lib/heap.c b/lib/heap.c
index 879147f..442fbea 100644
--- a/lib/heap.c
+++ b/lib/heap.c
@@ -63,7 +63,7 @@ hcl_heap_t* hcl_makeheap (hcl_t* hcl, hcl_oow_t size)
 	if (HCL_UNLIKELY(!heap))
 	{
 		const hcl_ooch_t* oldmsg = hcl_backuperrmsg(hcl);
-		hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "unable to allocate a heap - %js", oldmsg);
+		hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "unable to allocate a heap - %js", oldmsg);
 		return HCL_NULL;
 	}
 
diff --git a/lib/read.c b/lib/read.c
index 6430ba9..b7e6375 100644
--- a/lib/read.c
+++ b/lib/read.c
@@ -241,7 +241,7 @@ static int copy_string_to (hcl_t* hcl, const hcl_oocs_t* src, hcl_oocs_t* dst, h
 		if (HCL_UNLIKELY(!tmp))
 		{
 			const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-			hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to grow token buffer - %js", orgmsg);
+			hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to grow token buffer - %js", orgmsg);
 			return -1;
 		}
 
@@ -479,7 +479,7 @@ static const hcl_ooch_t* add_sr_name (hcl_t* hcl, const hcl_oocs_t* name)
 	if (HCL_UNLIKELY(!link))
 	{
 		const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-		hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to source name [%.*js] - %js", name->len, name->ptr, orgmsg);
+		hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to source name [%.*js] - %js", name->len, name->ptr, orgmsg);
 		return HCL_NULL;
 	}
 
@@ -503,7 +503,7 @@ static HCL_INLINE int enter_list (hcl_t* hcl, const hcl_loc_t* loc, int flagv)
 	if (HCL_UNLIKELY(!rstl))
 	{
 		const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-		hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to allocate reader stack node - %js", orgmsg);
+		hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to allocate reader stack node - %js", orgmsg);
 		return -1;
 	}
 	rstl->loc = *loc;
@@ -622,7 +622,7 @@ static HCL_INLINE hcl_cnode_t* leave_list (hcl_t* hcl, hcl_loc_t* list_loc, int*
 			if (HCL_UNLIKELY(!sym))
 			{
 				const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-				hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to create symbol cnode for := - %js", orgmsg);
+				hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to create symbol cnode for := - %js", orgmsg);
 				if (head) hcl_freecnode (hcl, head);
 				return HCL_NULL;
 			}
@@ -633,7 +633,7 @@ static HCL_INLINE hcl_cnode_t* leave_list (hcl_t* hcl, hcl_loc_t* list_loc, int*
 			if (HCL_UNLIKELY(!newhead))
 			{
 				const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-				hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to create cons cnode for := - %js", orgmsg);
+				hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to create cons cnode for := - %js", orgmsg);
 				hcl_freecnode (hcl, sym);
 				if (head) hcl_freecnode (hcl, head);
 				return HCL_NULL;
@@ -654,7 +654,7 @@ static HCL_INLINE hcl_cnode_t* leave_list (hcl_t* hcl, hcl_loc_t* list_loc, int*
 		if (HCL_UNLIKELY(!head))
 		{
 			const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-			hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to create empty list - %js", orgmsg);
+			hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to create empty list - %js", orgmsg);
 		}
 	}
 
@@ -935,7 +935,7 @@ static int feed_begin_include (hcl_t* hcl)
 	if (HCL_UNLIKELY(!arg))
 	{
 		const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-		hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to allocate source input structure - %js", orgmsg);
+		hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to allocate source input structure - %js", orgmsg);
 		goto oops;
 	}
 
@@ -2865,7 +2865,7 @@ int hcl_feed (hcl_t* hcl, const hcl_ooch_t* data, hcl_oow_t len)
 			x = feed_char(hcl, HCL_OOCI_EOF);
 			if (x <= -1)
 			{
-				if (hcl->c->feed.rd.level <= 0 && hcl_geterrnum(hcl) == HCL_ESYNERR && hcl_getsynerrnum(hcl) == HCL_SYNERR_EOF)
+				if (hcl->c->feed.rd.level <= 0 && HCL_ERRNUM(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);
@@ -3153,7 +3153,7 @@ static int init_compiler (hcl_t* hcl)
 	if (HCL_UNLIKELY(!hcl->c))
 	{
 		const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
-		hcl_seterrbfmt (hcl, hcl_geterrnum(hcl), "failed to allocate compiler - %js", orgmsg);
+		hcl_seterrbfmt (hcl, HCL_ERRNUM(hcl), "failed to allocate compiler - %js", orgmsg);
 		hcl_deregcb (hcl, cbp);
 		return -1;
 	}
diff --git a/lib/std.c b/lib/std.c
index b710b1a..c11e4ed 100644
--- a/lib/std.c
+++ b/lib/std.c
@@ -3231,7 +3231,7 @@ hcl_t* hcl_openstdwithmmgr (hcl_mmgr_t* mmgr, hcl_oow_t xtnsize, hcl_errnum_t* e
 	cb.vm_cleanup = cb_vm_cleanup;
 	if (hcl_regcb(hcl, &cb) == HCL_NULL)
 	{
-		if (errnum) *errnum = hcl_geterrnum(hcl);
+		if (errnum) *errnum = HCL_ERRNUM(hcl);
 		hcl_close (hcl);
 		return HCL_NULL;
 	}
diff --git a/pas/Makefile.am b/pas/Makefile.am
index d95e27d..24cb7b0 100644
--- a/pas/Makefile.am
+++ b/pas/Makefile.am
@@ -8,7 +8,7 @@ hcl_DEPENDENCIES = hcl.bin
 hcl_LINK = cp -pf hcl.bin $(builddir)/hcl$(EXEEXT) || echo 
 
 hcl.bin: $(hcl_SOURCES) ../lib/libhcl.la $(hcl_OBJECTS)
-	fpc -o$(builddir)/$@ -FcUTF-8 -Fl../lib -Fl../lib/.libs -Fl/usr/lib/gcc/x86_64-linux-gnu/11 $(srcdir)/main.pas
+	fpc -o$(builddir)/$@ -g -Mobjfpc -FcUTF8 -Fl../lib -Fl../lib/.libs -Fl/usr/lib/gcc/x86_64-linux-gnu/11 $(srcdir)/main.pas
 
 clean-local:
 	rm -f *.ppu *.res hcl.bin
diff --git a/pas/Makefile.in b/pas/Makefile.in
index 5708d1b..3bc1afe 100644
--- a/pas/Makefile.in
+++ b/pas/Makefile.in
@@ -621,7 +621,7 @@ uninstall-am: uninstall-binPROGRAMS
 
 
 hcl.bin: $(hcl_SOURCES) ../lib/libhcl.la $(hcl_OBJECTS)
-	fpc -o$(builddir)/$@ -FcUTF-8 -Fl../lib -Fl../lib/.libs -Fl/usr/lib/gcc/x86_64-linux-gnu/11 $(srcdir)/main.pas
+	fpc -o$(builddir)/$@ -g -Mobjfpc -FcUTF8 -Fl../lib -Fl../lib/.libs -Fl/usr/lib/gcc/x86_64-linux-gnu/11 $(srcdir)/main.pas
 
 clean-local:
 	rm -f *.ppu *.res hcl.bin
diff --git a/pas/hcl.pas b/pas/hcl.pas
index 48d3887..bda8ab6 100644
--- a/pas/hcl.pas
+++ b/pas/hcl.pas
@@ -8,17 +8,11 @@ unit HCL;
 
 interface
 
-type 
+type
 	Interp = class
-	public
+	protected
 		handle: pointer;
-	private
-		handle1: integer;
-		handle2: integer;
-		handle3: integer;
-		handle4: integer;
-		handle5: integer;
-		handle6: integer;
+
 	public
 		constructor Create (x: integer);
 		destructor Destroy; override;
@@ -34,12 +28,29 @@ type
 		function FetchErrorMsg(): string;
 	end;
 
-	InterpPtr = ^Interp;
+	Location = record
+		line: sizeint;
+		colm: sizeint;
+		filp: pwidechar;
+	end;
+	Synerr = record
+		num: integer;
+		loc: Location;
+		tgt: record
+			val: array[0..255] of widechar;
+			len: sizeint;
+		end;
+	end;
+
+	SynerrPtr = ^Synerr;
 
 (*----- external hcl function -----*)
 function hcl_errnum_to_errbcstr(errnum: integer; errbuf: pointer; errbufsz: sizeint): pointer; cdecl; external;
+function hcl_errnum_is_synerr(errnum: integer): boolean; cdecl; external;
+
 function hcl_openstd(xtnsize: sizeint; errnum: pointer): pointer; cdecl; external;
 procedure hcl_close(handle: pointer); cdecl; external;
+function hcl_geterrnum(handle: pointer): integer; cdecl; external;
 function hcl_geterrbmsg(handle: pointer): pansichar; cdecl; external;
 function hcl_ignite(handle: pointer; heapsize: sizeint): integer; cdecl; external;
 function hcl_addbuiltinprims(handle: pointer): integer; cdecl; external;
@@ -53,18 +64,19 @@ procedure hcl_detachccio(handle: pointer); cdecl; external;
 function hcl_attachudiostdwithbcstr(handle: pointer; udi: pansichar; udo: pansichar): integer; cdecl; external;
 procedure hcl_detachudio(handle: pointer); cdecl; external;
 function hcl_compile(handle: pointer; cnode: pointer; flags: integer): integer; cdecl; external;
-function hcl_execute(handle: pointer): integer; cdecl; external;
+function hcl_execute(handle: pointer): pointer; cdecl; external;
 procedure hcl_abort(handle: pointer) cdecl; external;
 
+procedure hcl_getsynerr(handle: pointer; synerr: SynerrPtr) cdecl; external;
 function hcl_count_ucstr(ptr: pwidechar): sizeint; cdecl; external;
 (*----- end external hcl function -----*)
 
 implementation
 
-uses sysutils;
+uses sysutils, math;
 
 constructor Interp.Create (x: integer);
-var 
+var
 	h: pointer;
 	errnum: integer;
 	errmsg: array[0..255] of AnsiChar;
@@ -89,11 +101,30 @@ end;
 
 function Interp.FetchErrorMsg(): string;
 var
-	bmsg: PAnsiChar;
+	num: integer;
+	bmsg: pansichar;
+	serr: Synerr;
+	filp: pwidechar;
+	tgt: array[0..255] of widechar;
 begin
-	(* TODO: if the errocode is syntax error. use the systax error message and locations info *)
-	bmsg := hcl_geterrbmsg(self.handle);
-	exit(string(bmsg))
+	num := hcl_geterrnum(self.handle);
+	if hcl_errnum_is_synerr(num) then begin
+		hcl_getsynerr(self.handle, @serr);
+		bmsg := hcl_geterrbmsg(self.handle);
+		filp := pwidechar(widestring(''));
+		if serr.loc.filp <> nil then filp := serr.loc.filp;
+		if serr.tgt.len > 0 then begin
+			sysutils.strlcopy(@tgt, serr.tgt.val, math.min(serr.tgt.len, length(tgt) - 1));
+			exit(format('%s at %s[%u:%u] - %s', [string(bmsg), string(filp), serr.loc.line, serr.loc.colm, string(tgt)]));
+		end
+		else begin
+			exit(format('%s at %s[%u:%u]', [string(bmsg), string(filp), serr.loc.line, serr.loc.colm]));
+		end;
+	end
+	else begin
+		bmsg := hcl_geterrbmsg(self.handle);
+		exit(string(bmsg))
+	end;
 end;
 
 procedure Interp.Ignite(heapsize: sizeint);
@@ -121,6 +152,7 @@ end;
 
 procedure Interp.Compile(text: pansichar; len: sizeint);
 var
+	errnum: integer;
 	errmsg: string;
 begin
 	if hcl_attachcciostdwithbcstr(self.handle, nil) <= -1 then begin
@@ -132,12 +164,16 @@ begin
 		hcl_detachccio(self.handle);
 		raise Exception.Create('failed to begin feeding - ' + errmsg)
 	end;
-	
+
 	if hcl_feedbchars(self.handle, text, len) <= -1 then begin
+		errnum := hcl_geterrnum(self.handle);
 		errmsg := self.FetchErrorMsg();
 		hcl_endfeed(self.handle);
 		hcl_detachccio(self.handle);
-		raise Exception.Create('failed to feed text - ' + errmsg)
+		if hcl_errnum_is_synerr(errnum) then
+			raise Exception.Create(errmsg)
+		else
+			raise Exception.Create('failed to feed text - ' + errmsg);
 	end;
 
 	if hcl_endfeed(self.handle) <= -1 then begin
@@ -156,6 +192,7 @@ end;
 
 procedure Interp.Compile(text: pwidechar; len: sizeint);
 var
+	errnum: integer;
 	errmsg: string;
 begin
 	if hcl_attachcciostdwithbcstr(self.handle, nil) <= -1 then begin
@@ -169,10 +206,14 @@ begin
 	end;
 
 	if hcl_feeduchars(self.handle, text, len) <= -1 then begin
+		errnum := hcl_geterrnum(self.handle);
 		errmsg := self.FetchErrorMsg();
 		hcl_endfeed(self.handle);
 		hcl_detachccio(self.handle);
-		raise Exception.Create('failed to feed text - ' + errmsg)
+		if hcl_errnum_is_synerr(errnum) then
+			raise Exception.Create(errmsg)
+		else
+			raise Exception.Create('failed to feed text - ' + errmsg);
 	end;
 
 	if hcl_endfeed(self.handle) <= -1 then begin
@@ -187,17 +228,18 @@ end;
 
 procedure Interp.Execute();
 var
-	n: integer;
+	errmsg: string;
 begin
 	if hcl_attachudiostdwithbcstr(self.handle, nil, nil) <= -1 then begin
 		raise Exception.Create('failed to attach udio handlers - ' + self.FetchErrorMsg())
 	end;
-	n := hcl_execute(self.handle);
-	hcl_detachudio(self.handle);
-	if n <= -1 then
-	begin	
-		raise Exception.Create('failed to execute - ' + self.FetchErrorMsg())
+	if hcl_execute(self.handle) = nil then begin
+		errmsg := self.FetchErrorMsg();
+		hcl_detachudio(self.handle);
+		raise Exception.Create('failed to execute - ' + errmsg)
 	end;
+
+	hcl_detachudio(self.handle);
 end;
 
 end. (* unit *)
diff --git a/pas/main.pas b/pas/main.pas
index 2839e4a..42950f2 100644
--- a/pas/main.pas
+++ b/pas/main.pas
@@ -4,55 +4,6 @@ program main;
 
 uses HCL, sysutils;
 
-(*
-function Make(): HCL.InterpPtr;
-var
-	x: HCL.Interp;
-begin
-	x := HCL.Interp.Create(20);
-	Make := @x;
-end;
-
-function Make2(): HCL.Interp;
-begin
-	Make2 := HCL.Interp.Create(20);
-end;
-
-
-var
-	x: HCL.Interp;
-	x2: ^HCL.Interp;
-begin
-	Write ('sizeof X=>');
-	Writeln (SizeOf(x));
-	x := HCL.Interp.Make(20);
-	Write ('instance sizeof X=>');
-	Writeln (x.InstanceSize());
-//	x.Open();
-//	x.Close();
-	x.Destroy();
-	//x.Free();
-
-	Write ('sizeof X2=>');
-	Writeln (SizeOf(x2));
-
-//	New(x2);
-//	x2^.Open();
-//	//x2^.Destroy();
-//	//x2^.Free();
-//	Dispose (x2);
-
-	x := Make2();
-	//Writeln (x.handle);
-	x.Destroy();
-	x := nil;
-
-//	x2 := Make();
-//	Writeln (x2^.handle);
-//	x2^.Destroy();
-end.
-*)
-
 var
 	x: HCL.Interp = nil;
 begin
@@ -65,11 +16,11 @@ begin
 		//x.AttachUDIO();
 
 		x.Compile(pwidechar('(printf "hello 동키콩\n")'));
-		x.Compile('(printf "hello 동키콩월드\n")');
-		x.Compile('(a := 20)');
-		x.Compile('(printf "%d\n" a)');
+		x.Compile('(printf "hello 동키콩월드\n") ');
+		x.Compile('(동가리오 := 20)');
+		x.Compile('(printf "%d %d\n" 동가리오 (* 동가리오 동가리오))');
 
-		x.Execute();
+		x.Execute(); // check if exception...
 	except
 		on e: Exception do
 			writeln ('exception:', e.Message);