COMTRAN

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COMTRAN (COMmercial TRANslator) is an early programming language developed at IBM. It was intended as the business programing equivalent of the scientific programming language FORTRAN (FORmula TRANslator). It served as one of the forerunners to the COBOL language. Developed by Bob Bemer, in 1957, the language was the first to feature the programming language element known as a picture clause.

1 Contributions to COBOL
2 Picture clause
3 Sample program
4 References
5 External links

[edit] Contributions to COBOL

Several elements of COMTRAN were incorporated into COBOL:

Picture clause. (See below.)
Paragraphing: dividing code into paragraphs (with line breaks not significant).
Paragraph names. Assigning names to paragraphs, and jumps (GO TO's) are to a paragraph name, not to a line number.
AT END clause on file input operations.
Figurative constant HIGH-VALUE.
Passing a numeric value (RETURN-CODE) back to the operating system when the program terminates.

[edit] Picture clause

Main article: Picture clause

A picture clause element defines the length of any given datum, much like a dictionary defines words. In particular a picture clause determines whether the datum contains letters and numbers, and other characteristics of the data, including format, size, and data type.

[edit] Sample program

This is a sample COMTRAN program, doing payroll calculations. (From IBM F28-8043 Commercial Translator General Reference Manual.)^[1]

01001 *PROCEDURE

01002 CALL (EMPLOYEE.NUMBER)  EMPLOYNO,
01003      (BONDEDUCTION)     BONDEDUCT,
01004      (BONDENOMINATION)  BONDENOM,
01005      (BONDACCUMULATION) BONDACCUM,
01006      (INSURANCE.PREM)   INSPREM,
01007      (RETIREMENT.PREM)  RETPREM,
01008      (DEPARTMENT.TOTAl) DPT.

01009 START. OPEN ALL FILES.

01010 GET.MASTER. GET MASTER, AT END DO END.OF.MASTERS.

01011 GET.DETAIL. GET DETAIL, AT END GO TO END.OF.DETAILS.

01012 COMPARE.EMPLOYEE.NUMBERS. GO TO COMPUTE.PAY WHEN DETAIL EMPLOYNO
01013       IS EQUAL TO MASTER EMPLOYNO, LOW.DETAIL WHEN DETAIL
01014       EMPLOYNO IS LESS THAN MASTER EMPLOYNO.

01015 HIGH.DETAIL. MOVE 'M' TO MASTER ERRORCODE, FILE MASTER IN
01016       ERROR.FILE.

01017         GET MASTER, AT END DO END.OF.MASTERS.

01018         GO TO COMPARE.EMPLOYEE.NUMBERS.

02001 LOW.DETAIL. MOVE 'D' TO DETAIL ERRORCODE, FILE DETAIL IN
02002        ERROR.FILE.

02003          GO TO GET.DETAIL.

02004 END.OF.MASTERS. IF DETAIL EMPLOYNO = HIGH.VALUE THEN GO TO
02005         END.OF.RUN OTHERWISE SET MASTER EMPLOYNO = HIGH.VALUE.

02006 END.OF.DETAILS. IF MASTEREMPLOYNO = HIGH.VALUE THEN GO TO
02007         END.OF.RUN OTHERWISE SET DETAIL EMPLOYNO = HIGH.VALUE, GO
02008         TO COMPARE.EMPLOYEE.NUMBERS.

02009 END.OF.RUN. MOVE CORRESPONDING GRAND.TOTAL TO PAYRECORD, FILE
02010        PAYRECORD, CLOSE ALL FILES.
02011          STOP 1234.

02012 COMPUTE.PAY. IF DETAIL HOURS IS GREATER THAN 40 THEN SET DETAIL
02013        GROSS = (DETAIL HOURS - 40) * MASTER RATE * 1.5.

02014        SET DETAIL GROSS = DETAIL GROSS + MASTER RATE * 40, DO
02015      FICA.ROUTINE, DO WITHHOLDING.TAX.ROUTINE.

02016        IF MASTER BONDEDUCT IS NOT EQUAL TO ZERO THEN DO
02017      BOND.ROUTINE.

02018        DO SEARCH FOR INDEX = 1(1)12.

02019 NET. SET PAYRECORD NETPAY = DETAIL GROSS - DETAIL FICA - DETAIL
02020        WHT -DETAIL RETIREMENT - DETAIL INSURANCE - DETAIL
02021        BONDEDUCT.