Search backwards for tokens, ~30% speedup. Still slow.

1 files changed, 8 insertions, 11 deletions

diff --git a/src/alf.c b/src/alf.c
index 27b6d86..7b27861 100644
--- a/src/alf.c
+++ b/src/alf.c
@@ -200,22 +200,19 @@ void store_token(int tok) {
 	}
 }
 
+/* search backwards, the tokens are stored with longer ones later
+   in the list. */
 int match_token(int pos) {
-	int i, bestmatch = -1;
+	int i;
 
-	for(i = 0; i < curr_token; i++) {
-		if(i == TOK_RESET || i == TOK_END)
-			continue;
+	for(i = curr_token - 1; i >= INIT_TOKEN; i--) {
 		if(memcmp(&input_buf[pos], tokentab[i].start, tokentab[i].length) == 0)
-			bestmatch = i;
-	}
-
-	if(bestmatch == -1) {
-		fprintf(stderr, "BUG: bestmatch is -1, this should never happen!\n");
-		exit(1);
+			return i;
 	}
 
-	return bestmatch;
+	/* hard-coded single character tokens map to their values, no need
+	   to search. */
+	return input_buf[pos];
 }
 
 void make_token(int start, int end) {