
A (Not So) Brief but (Very) Accurate History of PL/SQL - todsacerdoti
http://oracle-internals.com/blog/2020/04/29/a-not-so-brief-but-very-accurate-history-of-pl-sql/
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peter_d_sherman
"Kendall grabbed a copy of everything he could, returned to the Oracle office,
and began reading. One of the books he picked-up was a publication titled,
“DIANA: An Intermediate Language for Ada,” by Gerhard Goos, William A. Wulf,
Arthur Evans Jr., and Kenneth J. Butler. This publication, written as a
reference manual, contained not only the Ada language grammar but also the
Interface Definition Language (IDL) specification of the Descriptive
Intermediate Attributed Notation for Ada – the predominant Ada intermediate
representation of the time. With this information at hand, in January of 1987,
the first line of PL/SQL compiler code was written.

The PL/SQL compiler began as a verbatim copy of the specification. Kendall
wrote the original YACC-based parser using the manual’s Ada grammar and
generated a DIANA tree directly from the syntactic rule actions. Unlike
compilers for other languages, which often generate an abstract syntax tree
and then translate that tree to the intermediate language, this direct
approach worked well for an Ada-like language – particularly as the reference
manual represented the IDL and grammar in an interlaced fashion."

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cafard
Most interesting. Thank you for posting this.

