XTAL IF/​THEN/​ELSE

by Robert Gill

The following provides a routine for XTAL Basic to allow IF/​THEN/​ELSE structures to be used –

The routine is simple and only contains a couple of minor bugs:–

1. IF (EXPR) THEN REM ..... :ELSE .....
   The routine ignores REM if the IF/THEN proves false and an ELSE statement follows.
2. IF (EXPR) THEN PRINT "xy"
   If a REM or PRINT statement used after a THEN contains the characters of 0FF and 000, the routine will misinterpret that as an ELSE command.

The routine is fast causing a time delay under worst possible conditions of 1.3%.