cclist at sydex.com
Tue Oct 15 11:27:43 CDT 2019
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
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
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.
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