DIBOL manual

[Chuck Guzis]

On 10/15/19 8:07 AM, Noel Chiappa via cctalk wrote:

> I seem to recall that COBOL was the first language with support for 
> structures? If DIBOL has support for them too, which would be
> another similarity between the two.

Both FLOW-MATIC (1953) and COMTRAN (1957) had support for data
structures, though the data structure notation was not part of the
program procedure.  FLOW-MATIC placed the structure and naming
information on data tapes (pretty novel for the period) and COMTRAN put
the specification of data structure on separate fixed-field section the
program input.

The general idea (as explained in Grace Hopper's FLOW-MATIC description)
was to make the data record structuring an independent task.   She
mentions being able to work out the procedure section before designing
the data layout.   I suspect that her record layout is one of the
earliest DDLs.

COBOL built on this.  Looking at the procedure section of COMTRAN or
FLOW-MATIC programs, there's no mistaking them as COBOL predecessors.
DIBOL, not so much.

COBOL, by the late 60s was a very complex language, so much so that the
initial S/360 DOS releases were incomplete; they lacked support for ISAM
files.  Somewhere, I have an IBM document that describes the
machine-language subroutines that were provided to fill the gap
temporarily via the "ENTER LINKAGE" statement.

I'm not at all certain that FLOW-MATIC had the first structured data
description language, but it was pretty close.

--Chuck