Flython

[Terry Reedy]

"Christopher T King" <squirrel at WPI.EDU> wrote in message
news:Pine.LNX.4.44.0408161041590.8576-100000 at ccc3.wpi.edu...

>I'm using http://docs.python.org/ref/grammar.txt as my grammar
>reference.
...
> :(  Is there at least some rationale why the AST trees don't match the
> grammar definitions?

The grammar in the Ref Manual, which is collected together in the above
file, is intended and used for human comsumption.  The equivalent but not
identical grammar in a source code file is intended and used for
parser-generator comsumption.  It consitutes its own documentation.  You
aren't the first person to trip on the difference.  The rationale is that
people and parser generators 'think' differently.

I don't know whether AST trees exactly match the parser grammarr or if they
effectively follow a third form, hopefully also exactly equivalent.  You
have wandered into as-yet inadequately documented internals land.

Terry J. Reedy