+void
+normalize(SV *sv)
+PROTOTYPE: $
+PREINIT:
+ HV *hv, *res;
+ HE *key;
+ NV c = 0;
+CODE:
+ if (!SvOK(sv))
+ XSRETURN_UNDEF;
+ res = newHV();
+ if (!SvROK(sv)) {
+ sn_store_ent(res, sv, newSVuv(1), 0);
+ } else {
+ hv = (HV *) SvRV(sv);
+ if (!hv_iterinit(hv)) {
+ sn_store(res, "0", 1, newSVuv(1), 0);
+ } else {
+ while (key = hv_iternext(hv))
+ c += SvNV(HeVAL(key));
+ hv_iterinit(hv);
+ while (key = hv_iternext(hv)) {
+ SV *val = newSVnv(SvNV(HeVAL(key)) / c);
+ sn_store_ent(res, HeSVKEY_force(key), val, HeHASH(key));
+ }
+ }
+ }
+ ST(0) = sv_2mortal(newRV_noinc((SV *) res));
+ XSRETURN(1);
+
+void
+scale(SV *csv, SV *sv)
+PROTOTYPE: $;$
+PREINIT:
+ HV *hv, *res;
+ HE *key;
+ NV c = 1;
+CODE:
+ if (!SvOK(sv))
+ XSRETURN_UNDEF;
+ if (SvOK(csv))
+ c = SvNV(csv);
+ res = newHV();
+ if (!SvROK(sv)) {
+ sn_store_ent(res, sv, newSVnv(c), 0);
+ } else {
+ hv = (HV *) SvRV(sv);
+ if (!hv_iterinit(hv)) {
+ sn_store(res, "0", 1, newSVnv(c), 0);
+ } else {
+ hv_iterinit(hv);
+ while (key = hv_iternext(hv)) {
+ SV *val = newSVnv(SvNV(HeVAL(key)) * c);
+ sn_store_ent(res, HeSVKEY_force(key), val, HeHASH(key));
+ }
+ }
+ }
+ ST(0) = sv_2mortal(newRV_noinc((SV *) res));
+ XSRETURN(1);
+
+void
+add(...)
+PROTOTYPE: @
+PREINIT:
+ HV *res;
+ SV *cur, *val;
+ HE *key, *old;
+ I32 i;
+CODE:
+ if (!items)
+ XSRETURN_UNDEF;
+ res = newHV();
+ for (i = 0; i < items; ++i) {
+ cur = ST(i);
+ if (!SvOK(cur))
+ continue;
+ if (!SvROK(cur)) {
+ NV v = 1;
+ if ((old = hv_fetch_ent(res, cur, 1, 0)) && SvOK(val = HeVAL(old)))
+ v += SvNV(val);
+ sn_store_ent(res, cur, newSVnv(v), 0);
+ continue;
+ }
+ cur = SvRV(cur);
+ hv_iterinit((HV *) cur);
+ while (key = hv_iternext((HV *) cur)) {
+ SV *k = HeSVKEY_force(key);
+ NV v = SvNV(HeVAL(key));
+ if ((old = hv_fetch_ent(res, k, 1, 0)) && SvOK(val = HeVAL(old)))
+ v += SvNV(val);
+ sn_store_ent(res, k, newSVnv(v), 0);
+ }
+ }
+ if (!hv_iterinit(res)) {
+ SvREFCNT_dec(res);
+ XSRETURN_UNDEF;
+ }
+ ST(0) = sv_2mortal(newRV_noinc((SV *) res));
+ XSRETURN(1);
+
+void
+cumulate(SV *sv, SV *nsv, SV *csv)
+PROTOTYPE: $$$
+PREINIT:
+ HV *res;
+ HE *key;
+ NV c0, c, a;
+ UV i, n;
+CODE:
+ if (!SvOK(sv))
+ XSRETURN_UNDEF;
+ n = SvUV(nsv);
+ c0 = SvNV(csv);
+ if (!n) {
+ ST(0) = sv_2mortal(newSVuv(0));
+ XSRETURN(1);
+ }
+ if (!SvROK(sv) || !c0) {
+ ST(0) = sv;
+ XSRETURN(1);
+ }
+ sv = SvRV(sv);
+ if (!hv_iterinit((HV *) sv))
+ XSRETURN_UNDEF;
+ if (c0 == 1 || (SvIOK(csv) && SvIV(csv) == 1)) {
+ c = n;
+ } else {
+ c = 1;
+ a = c0;
+ for (; n > 0; n /= 2) {
+ if (n % 2)
+ c *= a;
+ a *= a;
+ }
+ c = (1 - c) / (1 - c0);
+ }
+ res = newHV();
+ while (key = hv_iternext((HV *) sv)) {
+ SV *k = HeSVKEY_force(key);
+ SV *val = newSVnv(c * SvNV(HeVAL(key)));
+ sn_store_ent(res, k, val, 0);
+ }
+ ST(0) = sv_2mortal(newRV_noinc((SV *) res));
+ XSRETURN(1);
+
+void
+combine(...)
+PROTOTYPE: @
+PREINIT:
+ HV *res[2];
+ SV *cur, *val;
+ SV *list1, *list2;
+ SV *temp;
+ HE *key, *old;
+ I32 i;
+ I32 n = 0, o;
+ I32 j, n1, n2;
+ UV shift = 0, do_shift = 0;
+ sn_combcache *cache = NULL;
+ I32 cachelen = 0;
+CODE:
+ if (!items)
+ XSRETURN_UNDEF;
+ res[0] = res[1] = NULL;
+ for (i = 0; i < items; ++i) {
+ cur = ST(i);
+ if (!SvOK(cur))
+ continue;
+ if (!SvROK(cur)) {
+ if (strEQ(SvPV_nolen(cur), "list")) {
+ res[0] = newHV();
+ n = 0;
+ sn_store(res[0], "list", 4, newSVuv(1), sn_hash_list);
+ i = items;
+ if (!shift)
+ do_shift = 0;
+ break;
+ } else {
+ shift += SvUV(cur);
+ do_shift = 1;
+ continue;
+ }
+ }
+ cur = SvRV(cur);
+ res[0] = newHV();
+ while (key = hv_iternext((HV *) cur))
+ sn_store_ent(res[0], HeSVKEY_force(key), newSVsv(HeVAL(key)), 0);
+ n = 0;
+ if (!shift)
+ do_shift = 0;
+ break;
+ }
+ temp = sv_2mortal(newSViv(0));
+ for (++i; i < items; ++i) {
+ cur = ST(i);
+ if (!SvOK(cur))
+ continue;
+ if (!SvROK(cur)) {
+ if (strEQ(SvPV_nolen(cur), "list")) {
+ hv_clear(res[n]);
+ sn_store(res[n], "list", 4, newSVuv(1), sn_hash_list);
+ shift = 0;
+ do_shift = 0;
+ break;
+ } else {
+ shift += SvUV(cur);
+ continue;
+ }
+ }
+ cur = SvRV(cur);
+ o = 1 - n;
+ if (!res[o])
+ res[o] = newHV();
+ else
+ hv_clear(res[o]);
+ list1 = hv_delete((HV *) cur, "list", 4, 0);
+ n1 = hv_iterinit((HV *) cur);
+ list2 = hv_delete(res[n], "list", 4, 0);
+ n2 = hv_iterinit(res[n]);
+ if ((list1 && !n1) || (list2 && !n2)) {
+ sn_store(res[o], "list", 4, newSViv(1), sn_hash_list);
+ n = o;
+ break;
+ } else if (list1 || list2) {
+ NV l1 = list1 ? SvNV(list1) : 0;
+ NV l2 = list2 ? SvNV(list2) : 0;
+ val = newSVnv(l1 + l2 - l1 * l2);
+ sn_store(res[o], "list", 4, val, sn_hash_list);
+ }
+ if (n2 > cachelen) {
+ Renew(cache, n2, sn_combcache);
+ cachelen = n2;
+ }
+ j = 0;
+ while (key = hv_iternext(res[n])) {
+ cache[j].k = SvUV(HeSVKEY_force(key));
+ cache[j].v = SvNV(HeVAL(key));
+ ++j;
+ }
+ while (key = hv_iternext((HV *) cur)) {
+ IV k = SvUV(HeSVKEY_force(key));
+ NV v = SvNV(HeVAL(key));
+ for (j = 0; j < n2; ++j) {
+ sv_setiv(temp, k + cache[j].k);
+ if ((old = hv_fetch_ent(res[o], temp, 1, 0)) && SvOK(val = HeVAL(old))) {
+ val = newSVnv(SvNV(val) + v * cache[j].v);
+ } else {
+ val = newSVnv(v * cache[j].v);
+ }
+ sn_store_ent(res[o], temp, val, 0);
+ }
+ }
+ n = o;
+ }
+ Safefree(cache);
+ if (shift || do_shift) {
+ if (!res[n]) {
+ res[n] = newHV();
+ sv_setiv(temp, shift);
+ sn_store_ent(res[n], temp, newSViv(1), 0);
+ } else {
+ o = 1 - n;
+ if (!res[o])
+ res[o] = newHV();
+ else
+ hv_clear(res[o]);
+ list1 = hv_delete(res[n], "list", 4, 0);
+ hv_iterinit(res[n]);
+ while (key = hv_iternext(res[n])) {
+ sv_setiv(temp, SvUV(HeSVKEY_force(key)) + shift);
+ sn_store_ent(res[o], temp, newSVsv(HeVAL(key)), 0);
+ }
+ if (list1)
+ sn_store(res[o], "list", 4, newSVsv(list1), sn_hash_list);
+ n = o;
+ }
+ } else if (!res[0] && !res[1])
+ XSRETURN_UNDEF;
+ if (n == 1)
+ SvREFCNT_dec(res[0]);
+ else if (res[1])
+ SvREFCNT_dec(res[1]);
+ ST(0) = sv_2mortal(newRV_noinc((SV *) res[n]));
+ XSRETURN(1);
+