make chin branch more explicit

Author: ben-schwen

src/chmatch.c

@@ -71,17 +71,23 @@ static SEXP chmatchMain(SEXP x, SEXP table, int nomatch, bool chin, bool chmatch
     for (int i = 0; i < tablelen; ++i) {
       int tl = hash_lookup(marks, td[i], 0);
       if (tl == -1) {
-        hash_set(marks, td[i], chin ? 1 : i + 1);
+        hash_set(marks, td[i], i + 1);
         nuniq--;
         if (nuniq == 0) break; // all found, stop scanning
       }
     }
 
-    const int not_found = chin ? 0 : nomatch;
-    #pragma omp parallel for num_threads(getDTthreads(xlen, true))
-    for (int i = 0; i < xlen; ++i) {
-      int tl = hash_lookup(marks, xd[i], 0);
-      ansd[i] = tl == -1 ? not_found : tl;
+    if (chin) {
+      #pragma omp parallel for num_threads(getDTthreads(xlen, true))
+      for (int i = 0; i < xlen; ++i) {
+        ansd[i] = hash_lookup(marks, xd[i], 0) > 0;
+      }
+    } else {
+      #pragma omp parallel for num_threads(getDTthreads(xlen, true))
+      for (int i = 0; i < xlen; ++i) {
+        const int m = hash_lookup(marks, xd[i], 0);
+        ansd[i] = (m < 0) ? nomatch : m;
+      }
     }
     UNPROTECT(nprotect);
     return ans;