Reimplement Pl with variadic templates

This is a bit safer and about as complex.

5 files changed, 101 insertions, 181 deletions

diff --git a/c/datalistview.cpp b/c/datalistview.cpp
index 661a68e..9c13ae8 100644
--- a/c/datalistview.cpp
+++ b/c/datalistview.cpp
@@ -34,7 +34,7 @@ void DataListView::ShowEpisode(int iEpisode)
 	lviValue.mask = LVIF_TEXT;
 
 	term_t t = PL_new_term_refs(3);
-	if (!Plp(t,"I",iEpisode)) return;
+	if (!PL_put_integer(t,iEpisode)) return;
 	qid_t q = PL_open_query(NULL, PL_Q_NORMAL,
 	    PL_predicate("episode_datum", 3, "episode_data"), t);
 
@@ -43,7 +43,8 @@ void DataListView::ShowEpisode(int iEpisode)
 		char *szValue;
 		TCHAR *tszKey, *tszValue;
 
-		if (!Plg(t+1,"ss",&szKey,&szValue)) continue;
+		if (!(PL_get_atom_chars(t+1,&szKey) && PL_get_atom_chars(t+2,&szValue)))
+			continue;
 
 		tszKey = TszFromSz(szKey, CP_UTF8);
 		if (!tszKey) continue;
diff --git a/c/defs.h b/c/defs.h
index 06b1ef1..f57989c 100644
--- a/c/defs.h
+++ b/c/defs.h
@@ -66,9 +66,55 @@ struct DataListView : public ListView
 };
 
 /* pl.cpp */
-int Pl(const char *, const char *, const char *, ...);
-int Plp(term_t, const char *, ...);
-int Plg(term_t, const char *, ...);
+int Pl(const char *, const char *);
+
+inline int PlPut(term_t t, int x) { return PL_put_integer(t, x); }
+inline int PlPut(term_t t, long x) { return PL_put_integer(t, x); }
+inline int PlPut(term_t t, long long x) { return PL_put_integer(t, x); }
+inline int PlPut(term_t t, atom_t x) { return PL_put_atom(t, x); }
+inline int PlPut(term_t t, char *x) { return PL_put_atom(t, PL_new_atom(x)); }
+inline int PlPut(term_t t, const char *x) { return PL_put_atom(t, PL_new_atom(x)); }
+inline int PlPut(term_t t, int *x) { return -1; }
+inline int PlPut(term_t t, long *x) { return -1; }
+inline int PlPut(term_t t, long long *x) { return -1; }
+inline int PlPut(term_t t, atom_t *x) { return -1; }
+inline int PlPut(term_t t, char **x) { return -1; }
+
+inline int PlGet(term_t t, int x) { return -1; }
+inline int PlGet(term_t t, long x) { return -1; }
+inline int PlGet(term_t t, long long x) { return -1; }
+inline int PlGet(term_t t, atom_t x) { return -1; }
+inline int PlGet(term_t t, char *x) { return -1; }
+inline int PlGet(term_t t, const char *x) { return -1; }
+inline int PlGet(term_t t, int *x) { return PL_get_integer(t, x); }
+inline int PlGet(term_t t, long *x) { return PL_get_long(t, x); }
+inline int PlGet(term_t t, long long *x) { return PL_get_int64(t, x); }
+inline int PlGet(term_t t, atom_t *x) { return PL_get_atom(t, x); }
+inline int PlGet(term_t t, char **x) { return PL_get_atom_chars(t, x); }
+
+template <typename T>
+int PlPutv(term_t t, T arg) { return PlPut(t, arg); }
+template <typename T, typename ...R>
+int PlPutv(term_t t, T arg, R... rest) { return PlPut(t, arg)? PlPutv(t+1, rest...): 0; }
+template <typename T>
+int PlGetv(term_t t, T arg) { return PlGet(t, arg); }
+template <typename T, typename ...R>
+int PlGetv(term_t t, T arg, R... rest) { return PlGet(t, arg)? PlGetv(t+1, rest...): 0; }
+template <typename T>
+int Countv(int i, T arg) { return i+1; }
+template <typename T, typename ...R>
+int Countv(int i, T arg, R... rest) { return Countv(i+1, rest...); }
+template <typename ...T>
+int Pl(const char *szMod, const char *szPred, T... args)
+{
+	int iArity = Countv(0, args...);
+	term_t t = PL_new_term_refs(iArity);
+	if (!PlPutv(t, args...)) return 0;
+	if (!PL_call_predicate(NULL, PL_Q_NORMAL, PL_predicate(szPred, iArity, szMod), t))
+		return 0;
+	if (!PlGetv(t, args...)) return 0;
+	return 1;
+}
 
 /* defs.h */
 #ifdef UNICODE
diff --git a/c/episodelistview.cpp b/c/episodelistview.cpp
index 8273e08..6430b17 100644
--- a/c/episodelistview.cpp
+++ b/c/episodelistview.cpp
@@ -29,7 +29,7 @@ EpisodeListView::EpisodeListView() : ListView((HMENU)IDC_EPISODELISTVIEW, 0)
 	lvc.cx = Dpi(30);
 	ListView_InsertColumn(m_hWnd, ELVSIRATING, &lvc);
 
-	if (!Pl("cfg","get_sort","i",&m_iSort))
+	if (!Pl("cfg","get_sort",&m_iSort))
 		m_iSort = 1;
 }
 
@@ -63,7 +63,7 @@ LRESULT EpisodeListView::HandleNotify(LPARAM lParam)
 	    {
 		int iColumn = lpNmLv->iSubItem+1;
 		m_iSort = abs(m_iSort) == iColumn? -m_iSort: iColumn;
-		Pl("cfg","set_sort","I",m_iSort);
+		Pl("cfg","set_sort",m_iSort);
 		DoSort();
 		ShowFocus();
 		break;
@@ -91,7 +91,7 @@ LRESULT EpisodeListView::HandleNotify(LPARAM lParam)
 		case CDDS_ITEMPREPAINT:
 		    {
 			extern HFONT g_fBold;
-			if (!Pl("track_episodes","watched","I",lpLvCd->nmcd.lItemlParam)) {
+			if (!Pl("track_episodes","watched",lpLvCd->nmcd.lItemlParam)) {
 				SelectObject(lpLvCd->nmcd.hdc, g_fBold);
 				return CDRF_NEWFONT;
 			}
@@ -102,9 +102,9 @@ LRESULT EpisodeListView::HandleNotify(LPARAM lParam)
 	    }
 	case NM_DBLCLK:		/* Open clicked episode. */
 	    {
-		if (!Pl("local_episodes","open_episode_locally","I",
+		if (!Pl("local_episodes","open_episode_locally",
 			m_lviFocus.lParam))
-			Pl("local_episodes","open_episode_online","I",
+			Pl("local_episodes","open_episode_online",
 			    m_lviFocus.lParam);
 		break;
 	    }
@@ -116,9 +116,9 @@ LRESULT EpisodeListView::HandleNotify(LPARAM lParam)
 		while ((lvi.iItem = ListView_GetNextItem(
 			    m_hWnd, lvi.iItem, LVNI_SELECTED)) != -1) {
 			if (!ListView_GetItem(m_hWnd, &lvi)) goto b;
-			if (!Pl("local_episodes","open_episode_locally","I",
+			if (!Pl("local_episodes","open_episode_locally",
 				lvi.lParam))
-				Pl("local_episodes","open_episode_online","I",
+				Pl("local_episodes","open_episode_online",
 				    lvi.lParam);
 		}
 	    b:	break;
@@ -150,7 +150,7 @@ void EpisodeListView::SaveFocus()
 	lvi.mask = LVIF_PARAM;
 	if ((lvi.iItem = ListView_GetNextItem(m_hWnd, -1, LVNI_FOCUSED)) != -1
 	    && ListView_GetItem(m_hWnd, &lvi))
-		Pl("cfg","set_focus","I",lvi.lParam);
+		Pl("cfg","set_focus",lvi.lParam);
 }
 
 void EpisodeListView::SetTop(int iItem)
@@ -167,7 +167,7 @@ void EpisodeListView::RestoreFocus()
 	LVFINDINFO lvfi;
 
 	iItem = 0;
-	if (!Pl("cfg","get_focus","i",&iEpisode)) return;
+	if (!Pl("cfg","get_focus",&iEpisode)) return;
 
 	lvfi.flags = LVFI_PARAM;
 	lvfi.lParam = iEpisode;
@@ -214,7 +214,7 @@ void EpisodeListView::SelectUnwatched(int iDir)
 
 	do {
 		if (!Pl("track_episodes",iDir > 0? "next_unwatched": "previous_unwatched",
-			"Ii",lvfi.lParam,&iEpNew))
+			lvfi.lParam,&iEpNew))
 			return;
 
 		lvfi.lParam = iEpNew;
@@ -276,23 +276,23 @@ void EpisodeListView::Update()
 	SendMessage(m_hWnd, WM_SETREDRAW, FALSE, 0);
 	ListView_DeleteAllItems(m_hWnd);
 
-	if (!Pl("episode_data","ensure_episode_data","")) return;
-	if (!Pl("episode_data","episode_count","i",&cEp)) return;
+	if (!Pl("episode_data","ensure_episode_data")) return;
+	if (!Pl("episode_data","episode_count",&cEp)) return;
 
 	for (iEp = 1, iItem = 0; iEp <= cEp; iEp++) {
 		extern char g_szLimitScreenwriter[];
 		extern int g_bViewTVOriginal, g_bViewWatched;
 
 		if (g_szLimitScreenwriter[0])
-			if (!Pl("episode_data","episode_datum","ISS",
+			if (!Pl("episode_data","episode_datum",
 				iEp,"Screenwriter",g_szLimitScreenwriter))
 				continue;
 		
 		if (!g_bViewWatched)
-			if (Pl("track_episodes","watched","I",iEp)) continue;
+			if (Pl("track_episodes","watched",iEp)) continue;
 
 		if (!g_bViewTVOriginal)
-			if (Pl("episode_data","tv_original","I",iEp)) continue;
+			if (Pl("episode_data","tv_original",iEp)) continue;
 
 		/* Format episode number string. */
 		_stprintf_s(tszEpisode, sizeof(tszEpisode), TEXT("%d"), iEp);
@@ -358,16 +358,16 @@ void EpisodeListView::UpdateItem(LPLVITEM lpLvi)
 	static TCHAR tszRating[3];
 
 	tszName = NULL;
-	if (!Pl("episode_data","episode_title","Is",lpLvi->lParam,&szName)) {
-		if (!Pl("episode_data","update_episode_data","")) goto r;
-		if (!Pl("episode_data","episode_title","Is",lpLvi->lParam,&szName))
+	if (!Pl("episode_data","episode_title",lpLvi->lParam,&szName)) {
+		if (!Pl("episode_data","update_episode_data")) goto r;
+		if (!Pl("episode_data","episode_title",lpLvi->lParam,&szName))
 			goto r;
 	}
 	tszName = TszFromSz(szName, CP_UTF8);
 	if (tszName)
 		ListView_SetItemText(m_hWnd, lpLvi->iItem, ELVSITITLE, tszName);
 
-r:	if (!Pl("episode_data","episode_rating","Ii",lpLvi->lParam,&iRating)) {
+r:	if (!Pl("episode_data","episode_rating",lpLvi->lParam,&iRating)) {
 		ListView_SetItemText(m_hWnd, lpLvi->iItem, ELVSIRATING, TEXT(""));
 		goto f;
 	}
@@ -423,8 +423,8 @@ int CALLBACK ElvSort(LPARAM iItem1, LPARAM iItem2, LPARAM lExtra)
 		int iRating1, iRating2;
 		iRating1 = lpElv->m_iSort > 0? 99: -1;
 		iRating2 = lpElv->m_iSort > 0? 99: -1;
-		Pl("episode_data","episode_rating","Ii",lvi1.lParam,&iRating1);
-		Pl("episode_data","episode_rating","Ii",lvi2.lParam,&iRating2);
+		Pl("episode_data","episode_rating",lvi1.lParam,&iRating1);
+		Pl("episode_data","episode_rating",lvi2.lParam,&iRating2);
 		if (iRating1 == iRating2)
 			return Cmp(lvi1.lParam, lvi2.lParam);
 		return iOrder*Cmp(iRating1, iRating2);
@@ -433,9 +433,9 @@ int CALLBACK ElvSort(LPARAM iItem1, LPARAM iItem2, LPARAM lExtra)
 	    {
 		char *sz1, *sz2;
 		int cch, cch1, cch2;
-		if (!Pl("episode_data","episode_title","Is",lvi1.lParam,&sz1))
+		if (!Pl("episode_data","episode_title",lvi1.lParam,&sz1))
 			return 0;
-		if (!Pl("episode_data","episode_title","Is",lvi2.lParam,&sz2))
+		if (!Pl("episode_data","episode_title",lvi2.lParam,&sz2))
 			return 0;
 		cch1 = strlen(sz1);
 		cch2 = strlen(sz2);
diff --git a/c/main.cpp b/c/main.cpp
index 1d8a981..2ae1c84 100644
--- a/c/main.cpp
+++ b/c/main.cpp
@@ -110,7 +110,7 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
 	ShowWindow(hWnd, nCmdShow);
 
 	/* Populate episode list view. */
-	Pl("track_episodes", "update_tracked_episodes", "");
+	Pl("track_episodes", "update_tracked_episodes");
 	g_lpElv->Update();
 	g_lpElv->RestoreFocus();
 
@@ -150,9 +150,9 @@ static LRESULT CALLBACK CBTProc(int nCode, WPARAM wParam, LPARAM lParam)
 
 	/* Get saved view settings. */
 	char *sz;
-	Pl("cfg","get_view_watched","i",&g_bViewWatched);
-	Pl("cfg","get_view_tv_original","i",&g_bViewTVOriginal);
-	if (Pl("cfg","get_limit_screenwriter","s",&sz))
+	Pl("cfg","get_view_watched",&g_bViewWatched);
+	Pl("cfg","get_view_tv_original",&g_bViewTVOriginal);
+	if (Pl("cfg","get_limit_screenwriter",&sz))
 		strcpy_s(g_szLimitScreenwriter, sizeof(g_szLimitScreenwriter), sz);
 	return 0;
 }
@@ -218,7 +218,7 @@ LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 		case WA_ACTIVE:
 		case WA_CLICKACTIVE:
 			SetFocus(g_hFocus);
-			Pl("track_episodes","update_tracked_episodes","");
+			Pl("track_episodes","update_tracked_episodes");
 			g_lpElv->Redraw();
 		}
 		break;
@@ -236,7 +236,7 @@ LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 
 			/* Animate ellipsis in status bar while doing
 			 * work in other thread. */
-			if (Pl("episode_data","thread_running","A",g_aThread)) {
+			if (Pl("episode_data","thread_running",g_aThread)) {
 				i = (i+1)%4;
 				SendMessage(g_hWndStatus, SB_SETTEXT, MAKEWPARAM(1,0),
 				    (LPARAM)(i==0? TEXT("."):
@@ -262,11 +262,11 @@ LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 			break;
 		case IDM_FILE_FETCH_DATA:
 			if (g_bThread) break;
-			Pl("episode_data","thread_create","Sa","update_episode_data",&g_aThread);
+			Pl("episode_data","thread_create","update_episode_data",&g_aThread);
 			goto t;
 		case IDM_FILE_FETCH_SCREENWRITERS:
 			if (g_bThread) break;
-			Pl("episode_data","thread_create","Sa","update_screenwriters",&g_aThread);
+			Pl("episode_data","thread_create","update_screenwriters",&g_aThread);
 		t:	KillTimer(hWnd, IDT_TIMER);
 			SetTimer(hWnd, IDT_TIMER, 500, NULL);
 			SendMessage(g_hWndStatus, SB_SETTEXT, MAKEWPARAM(1,0), (LPARAM)TEXT("."));
@@ -285,7 +285,7 @@ LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 			CheckMenuItem(GetMenu(hWnd), IDM_VIEW_WATCHED,
 			    g_bViewWatched? MF_UNCHECKED: MF_CHECKED);
 			g_bViewWatched = !g_bViewWatched;
-			Pl("cfg","set_view_watched","I",g_bViewWatched);
+			Pl("cfg","set_view_watched",g_bViewWatched);
 			g_lpElv->Update();
 			g_lpElv->EnsureFocusVisible();
 			break;
@@ -295,7 +295,7 @@ LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 			CheckMenuItem(GetMenu(hWnd), IDM_VIEW_TV_ORIGINAL,
 			    g_bViewTVOriginal? MF_UNCHECKED: MF_CHECKED);
 			g_bViewTVOriginal = !g_bViewTVOriginal;
-			Pl("cfg","set_view_tv_original","I",g_bViewTVOriginal);
+			Pl("cfg","set_view_tv_original",g_bViewTVOriginal);
 			g_lpElv->Update();
 			g_lpElv->EnsureFocusVisible();
 			break;
@@ -317,14 +317,14 @@ LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 				if (!ListView_GetItem(g_lpElv->HWnd(), &lvi)) break;
 
 				char *sz;
-				if (!Pl("episode_data","episode_datum","ISs",lvi.lParam,"Screenwriter",&sz))
+				if (!Pl("episode_data","episode_datum",lvi.lParam,"Screenwriter",&sz))
 					break;
 				strcpy_s(g_szLimitScreenwriter,
 				    sizeof(g_szLimitScreenwriter), sz);
 				CheckMenuItem(GetMenu(hWnd), IDM_VIEW_OTHERS,
 				    MF_UNCHECKED);
 			}
-			Pl("cfg","set_limit_screenwriter","S",g_szLimitScreenwriter);
+			Pl("cfg","set_limit_screenwriter",g_szLimitScreenwriter);
 			g_lpElv->Update();
 			g_lpElv->EnsureFocusVisible();
 			break;
@@ -361,28 +361,28 @@ LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 
 				switch (LOWORD(wParam)) {
 				case IDM_WATCH_LOCALLY:
-					Pl("local_episode","open_episode_locally","I",lvi.lParam);
+					Pl("local_episode","open_episode_locally",lvi.lParam);
 					break;
 				case IDM_WATCH_ONLINE:
-					Pl("local_episode","open_episode_online","I",lvi.lParam);
+					Pl("local_episode","open_episode_online",lvi.lParam);
 					break;
 				case IDM_TOGGLE:
-					Pl("track_episodes","toggle_episode","I",lvi.lParam);
+					Pl("track_episodes","toggle_episode",lvi.lParam);
 					g_lpElv->Redraw();
 					break;
 				case IDM_FORGET:
-					Pl("track_episodes","forget_episode","I",lvi.lParam);
-					Pl("track_episodes","update_tracked_episodes","");
+					Pl("track_episodes","forget_episode",lvi.lParam);
+					Pl("track_episodes","update_tracked_episodes");
 					g_lpElv->Redraw();
 					break;
 				case IDM_LOOKUP:
-					Pl("episode_data","retract_episode","I",lvi.lParam);
+					Pl("episode_data","retract_episode",lvi.lParam);
 					g_lpElv->UpdateItem(&lvi);
 					g_lpElv->Redraw();
 					g_lpDlv->ShowEpisode(lvi.lParam);
 					break;
 				case IDM_WIKI:
-					Pl("episode_data","open_episode_wiki","I",lvi.lParam);
+					Pl("episode_data","open_episode_wiki",lvi.lParam);
 					break;
 				case IDM_RATE10:
 					iRating = 10;
@@ -416,7 +416,7 @@ LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 					goto r;
 				case IDM_RATE0:
 					iRating = 0;
-				r:	Pl("episode_data","rate_episode","II",lvi.lParam,iRating);
+				r:	Pl("episode_data","rate_episode",lvi.lParam,iRating);
 					g_lpElv->UpdateItem(&lvi);
 					break;
 				}
@@ -489,8 +489,8 @@ HWND CreateStatusBar(HWND hWndParent, HINSTANCE hInstance)
 /* Attach persistent databases. */
 int Attach()
 {
-	if (!Pl("track_episodes","attach","")) return 0;
-	if (!Pl("episode_data","attach","")) return 0;
+	if (!Pl("track_episodes","attach")) return 0;
+	if (!Pl("episode_data","attach")) return 0;
 	return 1;
 }
 
diff --git a/c/pl.cpp b/c/pl.cpp
index 7c86d0d..30b70a9 100644
--- a/c/pl.cpp
+++ b/c/pl.cpp
@@ -1,136 +1,9 @@
-#include <stdarg.h>
-#include <string.h>
 #include <SWI-Prolog.h>
-#include "defs.h"
 
-static int Plpv(term_t, const char *, va_list);
-static int Plgv(term_t, const char *, va_list);
-
-/* Call Prolog predicate once. */
-int Pl(const char *szMod, const char *szPred, const char *szFmt, ...)
-{
-	int iArity;
-	term_t t;
-	va_list vl, vl2;
-
-	iArity = strlen(szFmt);
-	t = PL_new_term_refs(iArity);
-
-	va_start(vl, szFmt);
-	va_copy(vl2, vl);
-
-	if (!Plpv(t, szFmt, vl)) goto f;
-	if (!PL_call_predicate(NULL, PL_Q_NORMAL,
-		PL_predicate(szPred, iArity, szMod), t))
-		goto f;
-	if (!Plgv(t, szFmt, vl2)) goto f;
-
-	va_end(vl);
-	va_end(vl2);
-	return 1;
-f:	va_end(vl);
-	va_end(vl2);
-	return 0;
-}
-
-/* Put known values in term. */
-int Plp(term_t t, const char *szFmt, ...)
-{
-	int r;
-	va_list vl;
-	va_start(vl, szFmt);
-	r = Plpv(t, szFmt, vl);
-	va_end(vl);
-	return r;
-}
-int Plpv(term_t t, const char *szFmt, va_list vl)
-{
-	int i;
-	for (i = 0; szFmt[i]; i++) {
-		switch (szFmt[i]) {
-		case 'I':
-		    {
-			int x;
-			x = va_arg(vl, int);
-			if (!PL_put_integer(t+i, x)) return 0;
-			break;
-		    }
-		case 'A':
-		    {
-			atom_t x;
-			x = va_arg(vl, atom_t);
-			if (!PL_put_atom(t+i, x)) return 0;
-			break;
-		    }
-		case 'S':
-		    {
-			atom_t a;
-			char *x;
-			x = va_arg(vl, char *);
-			a = PL_new_atom(x);
-			if (!PL_put_atom(t+i, a)) return 0;
-			break;
-		    }
-		case 'i':
-			va_arg(vl, int *);
-			break;
-		case 'a':
-			va_arg(vl, atom_t *);
-			break;
-		case 's':
-			va_arg(vl, char **);
-			break;
-		}
-	}
-	return 1;
-}
-
-/* Get unknown values from term. */
-int Plg(term_t t, const char *szFmt, ...)
-{
-	int r;
-	va_list vl;
-	va_start(vl, szFmt);
-	r = Plgv(t, szFmt, vl);
-	va_end(vl);
-	return r;
-}
-int Plgv(term_t t, const char *szFmt, va_list vl)
+int Pl(const char *szMod, const char *szPred)
 {
-	int i;
-	for (i = 0; szFmt[i]; i++) {
-		switch (szFmt[i]) {
-		case 'i':
-		    {
-			int *lp;
-			lp = va_arg(vl, int *);
-			if (!PL_get_integer(t+i, lp)) return 0;
-			break;
-		    }
-		case 'a':
-		    {
-			atom_t *lp;
-			lp = va_arg(vl, atom_t *);
-			if (!PL_get_atom(t+i, lp)) return 0;
-			break;
-		    }
-		case 's':
-		    {
-			char **lp;
-			lp = va_arg(vl, char **);
-			if (!PL_get_atom_chars(t+i, lp)) return 0;
-			break;
-		    }
-		case 'I':
-			va_arg(vl, int);
-			break;
-		case 'A':
-			va_arg(vl, atom_t);
-			break;
-		case 'S':
-			va_arg(vl, char *);
-			break;
-		}
-	}
+	term_t t = PL_new_term_refs(0);
+	if (!PL_call_predicate(NULL, PL_Q_NORMAL, PL_predicate(szPred, 0, szMod), t))
+		return 0;
 	return 1;
 }