added byte_rfind (close #239)

src/std/bytes.c

@@ -120,6 +120,18 @@ HL_PRIM int hl_bytes_find( vbyte *where, int pos, int len, vbyte *which, int wpo
 	return (int)(size_t)(found - where);
 }
 
+HL_PRIM int hl_bytes_rfind( vbyte *where, int len, vbyte *which, int wlen ) {
+	if( wlen > len ) return -1;
+	if( wlen == 0 ) return len; // at end
+	int pos = len - wlen;
+	while( pos > 0 ) {
+		if( memcmp(where+pos,which,wlen) == 0 )
+			return pos;
+		pos--;
+	}
+	return -1;
+}
+
 HL_PRIM void hl_bytes_fill( vbyte *bytes, int pos, int len, int value ) {
 	memset(bytes+pos,value,len);
 }
@@ -226,6 +238,7 @@ DEFINE_PRIM(_VOID,bytes_blit,_BYTES _I32 _BYTES _I32 _I32);
 DEFINE_PRIM(_I32,bytes_compare,_BYTES _I32 _BYTES _I32 _I32);
 DEFINE_PRIM(_I32,string_compare,_BYTES _BYTES _I32);
 DEFINE_PRIM(_I32,bytes_find,_BYTES _I32 _I32 _BYTES _I32 _I32);
+DEFINE_PRIM(_I32,bytes_rfind,_BYTES _I32 _BYTES _I32);
 DEFINE_PRIM(_VOID,bytes_fill,_BYTES _I32 _I32 _I32);
 DEFINE_PRIM(_F64, parse_float,_BYTES _I32 _I32);
 DEFINE_PRIM(_NULL(_I32), parse_int, _BYTES _I32 _I32);