Script Expressions
An expression can be either a test expression or an action expression. An expression can occupy several rows. Several action expressions can be separated by a ";".
A test expression is an expression that returns a value. It can only be used in an IF or ELSE IF statement, or in an assignment ("variable = test expression"). Note that an assignment can be used in an IF or ELSE IF statement, where the test will be if the value is zero (false) or non-zero (true).
Examples of test expression:
| COMMENT | call subroutine 10 if var is greater than 5 |
|---|---|
| IF | var > 5 |
| THEN | CALL SR10; |
| COMMENT | increment loop index and compare if |
| loop is finished, otherwise go back | |
| IF | (ix = ix + 1) < 10 |
| THEN | GOTO POS10; |
| COMMENT | check if flag variable is true |
| (non-zero), then clear flag and take action | |
| IF | readyflag |
| THEN | readyflag = 0; CALL SR20; |
An action expression is an assignment or an instruction. Several assignments can be performed after each other.
| COMMENT | return if all is done |
|---|---|
| IF | alldone |
| THEN | RETURN; |
| COMMENT | several assignments |
| DO | var1 = var2 = var3 * 10; |