HP 3000 Manuals HP 3000 Manuals
Boolean Operators in Conditionals
Allow the option of including 'AND' and 'OR' operators in the condition
clauses of 'IF', 'WHILE', and 'REPEAT' verbs.
Syntax
...condition [AND|OR condition [AND|OR condition...] ]
Parameters
condition Current condition clause syntax. Refer to the Transact
Manual.
AND Logical conjunction. The truth value is true if both of
the conditions are true; false if one of the conditions
is false.
OR Optional operator. Logical inclusive OR. The truth
value is true if one or both of the conditions are true;
false if both of the conditions are false.
Discussion
This enhancement allows users to create complex conditions for evaluation
by the IF, WHILE, and REPEAT verbs. The operator precedence for complex
conditions is:
1. Arithmetic expressions are evaluated.
2. Truth values are established for simple conditions as follows:
a. Relation conditions;
b. Class conditions.
3. Multiple value conditions.
4. Truth values are established for complex conditions as follows:
a. Establish truth values for AND conditions.
b. Establish truth values for OR conditions.
Transact programmers will be able to use parentheses to indicate order of
precedence when evaluating a condition clause. Multiple value conditions
imply a higher order of precedence. Evaluation of the condition clause
will terminate as soon as a truth value can be determined.
Example
1) IF (LAST-NAME) = "SMITH" AND (FIRST-NAME) = "JACK" THEN ...
2) IF (ACCT-BALANCE) < 0 OR (LOAN-AMOUNT) >= (LOAN-MAX) THEN ...
3) IF (RENTAL-OFFICE) = "098","978","656" AND
(CUST-NO-PREFIX) = (PREFERRED-PREFIX) OR
(CUST-NAME) = "ABC Inc." THEN ...
4) WHILE (BALANCE) < 0 AND STATUS = 0
DO
GET(CHAIN) CUST-DETAIL,STATUS;
LET (BALANCE) = (BALANCE) + (AMOUNT);
DOEND;
5) REPEAT
DO
LET (TOTAL-OVERDUE) = (TOTAL-OVERDUE) + (AMT-OVERDUE);
FIND(SERIAL) CUST-INVOICE,STATUS;
DOEND
UNTIL (TOTAL-OVERDUE) > 999999.99 OR
(TOTAL-OVERDUE) > (MIN-OVERDUE) AND
(CUST-CODE) = "NEW";