Paul McGuire wrote: > Back in the mid-90's, Kees Blom generated a set of railroad syntax diagrams > for Python > (http://python.project.cwi.nl/search/hypermail/python-1994q3/0286.html). > This pre-dates any Python awareness on my part, but I'm sure this would have > been version 1.3 or something. > > For those who are not familiar with railroad syntax diagrams, they show a > grammar's syntax using arrows and blocks, instead of BNF - here's an excerpt > from the Python grammar, plus "ASCII-art" diagrams - must be viewed in > non-prop font to be appreciated: > > suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT > > ----+--> simple_stmt --------------------------------->\ > | | > \--> NEWLINE --> INDENT --+--> stmt --+--> DEDENT --+--> > / | > \----<-------/ > > if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite] > > > --> 'if' -> test --> ':' --> suite -->+ > | > ------------<-------------------+ > / > + > | ------------<------------------------ > |/ \ > + | > | | > +-> 'elif' -> test -> ':' --> suite -->/ > | > | > +-> 'else' -> ':' --> suite --> > | \ > \---------------->--------------+-------> > > > I was recently contacted by a volunteer in Banda Aceh teaching tsunami > refugees how to program in Python (new job skills and all that), and he > asked if there were any updated versions of these diagrams, or if it would > be difficult to generate them anew. It seems that railroad diagrams are > nice and unambiguous for his students to use, in the face of verbal language > barriers. > > I have written a pyparsing parser that reads the grammar file that ships > with Python - the parser is included in the latest release of pyparsing, and > also online at the pyparsing.wikispaces.com - but I have no graph-generating > tools to go the next step: generation of the railroad diagrams (in something > more legible/appealing than ASCII-art!). > > Anyone interested in helping complete this last step? > > Thanks, > -- Paul I googlled and got these: http://www.informatik.uni-freiburg.de/~thiemann/haskell/ebnf2ps/ http://www.antlr.org/share/1107033888258/SDG2-1.5.zip
- Paddy. -- http://mail.python.org/mailman/listinfo/python-list
