johnf wrote:
I've been in the programming business for over 20 years and I have never had a
need for a parser. But recently I have need to convert code from one
language to a my new language python.
Pray tell: what is the other language, and why do you want to convert
programs?
I assume you want to convert so you can then modify / extend the old
programs. If you just plan to run them in Python "as is" I see no value
in converting!
It is hard to map programs in other languages to Python because Python
is so different. A direct translation would not take advantage of
python's uniqueness.
What a better way to learn the new
language python than a new project. I decided it might be time to learn a
little something about parsers too. However, I soon discovered that I was
walking into the world of compiler writers and theories of computer
scientist. I paid for and downloaded a paper from O'Reilly books on what I
thought was going to be on 'pyparser'. But that turned out to be mostly
theory. And nothing about the use of pyparser.
So I ask you guys is there a link to a practical tutorial that provides hands
on information on the use of a python parser. I'd like to see something that
demo's converting a real language to python. When I google parsers I have
found a few simple code examples of parsing a float. Not really much help (I
could have done that using Regex) when you want to parse 'if,then' statements
that can be recursive.
FWIW I have written a parser for parts of the CMS Pipelines language. I
provide a form of BNF for the syntax, generate parsers from that, run a
"program" through that, which generates lists or dictionaries. I have no
need to create a program from that.
The Pipelines language is very simple, so I am not dealing with control
structures, just sequences of words and symbols.
--
Bob Gailer
Chapel Hill NC
919-636-4239
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