1 files changed, 5 insertions, 18 deletions

diff --git a/lptree.c b/lptree.c
index 700398b..9861cfe 100644
--- a/lptree.c
+++ b/lptree.c
@@ -723,37 +723,25 @@ static int lp_behind (lua_State *L) {
 */
 static int lp_throw (lua_State *L) {
         int label = luaL_checkinteger(L, -1);
-        luaL_argcheck(L, label >= 0 && label < MAXLABELS, -1, "the number of a label must be between 0 and 255");
+        luaL_argcheck(L, label >= 1 && label < MAXLABELS, -1, "the number of a label must be between 1 and 255");
         newthrowleaf(L, label);
         return 1;
 }
 
 /*
-** labeled choice function
+** labeled recovery function
 */
-static int lp_labchoice (lua_State *L) {
-        int n = lua_gettop(L);
-        TTree *tree = newrootlab2sib(L, TLabChoice);
-        int i;
-        for (i = 3; i <= n; i++) {
-                int d = luaL_checkinteger(L, i);
-                luaL_argcheck(L, d >= 0 && d < MAXLABELS, i, "the number of a label must be between 0 and 255");
-    setlabel(treelabelset(tree), (byte)d);
-        }
-  return 1;
-}
-
-
 static int lp_recovery (lua_State *L) {
         int n = lua_gettop(L);
         TTree *tree = newrootlab2sib(L, TRecov);
+  luaL_argcheck(L, n >= 3, 3, "non-nil value expected");
   if (n == 2) {  /* catches fail as default */
                 /*setlabel(treelabelset(tree), LFAIL);  recovery does not catch regular fail */
   } else {
                 int i;
                 for (i = 3; i <= n; i++) {
                         int d = luaL_checkinteger(L, i);
-                        luaL_argcheck(L, d >= 0 && d < MAXLABELS, i, "the number of a label must be between 0 and 255");
+                        luaL_argcheck(L, d >= 1 && d < MAXLABELS, i, "the number of a label must be between 1 and 255");
         setlabel(treelabelset(tree), (byte)d);
                 }
         }
@@ -1089,7 +1077,7 @@ static int verifyrule (lua_State *L, TTree *tree, int *passed, int npassed,
         return nb;
       /* else return verifyrule(L, sib2(tree), passed, npassed, nb); */
       tree = sib2(tree); goto tailcall;
-    case TChoice: case TLabChoice: case TRecov: /* must check both children */  /* labeled failure */
+    case TChoice:  case TRecov: /* must check both children */  /* labeled failure */
       nb = verifyrule(L, sib1(tree), passed, npassed, nb);
       /* return verifyrule(L, sib2(tree), passed, npassed, nb); */
       tree = sib2(tree); goto tailcall;
@@ -1342,7 +1330,6 @@ static struct luaL_Reg pattreg[] = {
   {"setmaxstack", lp_setmax},
   {"type", lp_type},
   {"T", lp_throw}, /* labeled failure throw */
-  {"Lc", lp_labchoice}, /* labeled failure choice */
   {"Rec", lp_recovery}, /* labeled failure choice */
   {NULL, NULL}
 };