Ada interfaces with Cobol - ada

Question

I am studying the Ada-> Cobol interface, and am wondering if there is any way to write the files to cobol default, without having to have a Cobol code written too, because I want to write a file using some rules of COBOL, but would to know how to do this directly in Ada.
For example, to read a file with cobol structure, I can use use that way:
with Interfaces.COBOL;
with COBOL_Sequential_IO; -- Assumed to be supplied by implementation
procedure Test_External_Formats is
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-- Using data created by a COBOL program
-- Assume that a COBOL program has created a sequential file with
-- the following record structure, and that we need to
-- process the records in an Ada program
-- 01 EMPLOYEE-RECORD
-- 05 NAME PIC X(20).
-- 05 SSN PIC X(9).
-- 05 SALARY PIC 99999V99 USAGE COMP.
-- 05 ADJUST PIC S999V999 SIGN LEADING SEPARATE.
-- The COMP data is binary (32 bits), high-order byte first
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package COBOL renames Interfaces.COBOL;
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type Salary_Type is delta 0.01 digits 7;
type Adjustments_Type is delta 0.001 digits 6;
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type COBOL_Employee_Record_Type is -- External representation
record
Name : COBOL.Alphanumeric(1..20);
SSN : COBOL.Alphanumeric(1..9);
Salary : COBOL.Byte_Array(1..4);
Adjust : COBOL.Numeric(1..7); -- Sign and 6 digits
end record;
pragma Convention (COBOL, COBOL_Employee_Record_Type);
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package COBOL_Employee_IO is
new COBOL_Sequential_IO(COBOL_Employee_Record_Type);
use COBOL_Employee_IO;
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COBOL_File : File_Type;
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type Ada_Employee_Record_Type is -- Internal representation
record
Name : String(1..20);
SSN : String(1..9);
Salary : Salary_Type;
Adjust : Adjustments_Type;
end record;
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COBOL_Record : COBOL_Employee_Record_Type;
Ada_Record : Ada_Employee_Record_Type;
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package Salary_Conversions is
new COBOL.Decimal_Conversions(Salary_Type);
use Salary_Conversions;
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package Adjustments_Conversions is
new COBOL.Decimal_Conversions(Adjustments_Type);
use Adjustments_Conversions;
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begin
Open (COBOL_File, Name => "Some_File");
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loop
Read (COBOL_File, COBOL_Record);
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Ada_Record.Name := To_Ada(COBOL_Record.Name);
Ada_Record.SSN := To_Ada(COBOL_Record.SSN);
Ada_Record.Salary :=
To_Decimal(COBOL_Record.Salary, COBOL.High_Order_First);
Ada_Record.Adjust :=
To_Decimal(COBOL_Record.Adjust, COBOL.Leading_Separate);
... -- Process Ada_Record
end loop;
exception
when End_Error => ...
end Test_External_Formats;
Put, I don't know how to write a File with cobol structure, in the documentation, I not find a way; http://www-users.cs.york.ac.uk/~andy/lrm95/b_04.htm
For example, if I have that struct in Cobol ( based on this sample: http://www.csis.ul.ie/cobol/examples/Sort/MaleSort.htm ; http://www.csis.ul.ie/cobol/examples/SeqIns/STUDENTS.DAT )
FILE SECTION.
FD StudentFile.
01 StudentRec PIC X(30).
88 EndOfFile VALUE HIGH-VALUES.
FD MaleStudentFile.
01 MaleStudentRec PIC X(30).
SD WorkFile.
01 WorkRec.
02 FILLER PIC 9(7).
02 WStudentName PIC X(10).
02 FILLER PIC X(12).
02 WGender PIC X.
88 MaleStudent VALUE "M".
How I can make a program to write this struct, in Ada, using Cobol interfaces ?

Answer 1

Think physically. That is, what is the output file's format? Whether you create that file in Cobol or Ada is NOT an immediate issue when designing a file.
Let's assume that Cobol Workrec describes your file's format. Do you want to write an Ada program that calls a cobol subroutine to physically write the file? or do you want to use a Cobol program to write the file? Or do you want an Ada program that writes a file in the smae format as Workrec?? Your choice depends on your customer's requirements.