82 lines
2.2 KiB
Plaintext
82 lines
2.2 KiB
Plaintext
PEP: 306
|
||
Title: How to Change Python's Grammar
|
||
Version: $Revision$
|
||
Last-Modified: $Date$
|
||
Author: Michael Hudson <mwh@python.net>
|
||
Status: Active
|
||
Type: Informational
|
||
Content-Type: text/plain
|
||
Created: 29-Jan-2003
|
||
Post-History: 30-Jan-2003
|
||
|
||
|
||
Abstract
|
||
|
||
There's more to changing Python's grammar than editing
|
||
Grammar/Grammar and Python/compile.c. This PEP aims to be a
|
||
checklist of places that must also be fixed.
|
||
|
||
It is probably incomplete. If you see omissions, just add them if
|
||
you can -- you are not going to offend the author's sense of
|
||
ownership. Otherwise submit a bug or patch and assign it to mwh.
|
||
|
||
This PEP is not intended to be an instruction manual on Python
|
||
grammar hacking, for several reasons.
|
||
|
||
|
||
Rationale
|
||
|
||
People are getting this wrong all the time; it took well over a
|
||
year before someone noticed[1] that adding the floor division
|
||
operator (//) broke the parser module.
|
||
|
||
|
||
Checklist
|
||
|
||
__ Grammar/Grammar: OK, you'd probably worked this one out :)
|
||
|
||
__ Python/compile.c: you'll most likely need to edit both the
|
||
actual compiler and the symtable builder (which is to say both
|
||
the com_foo and the sym_foo functions).
|
||
|
||
__ You may need to regenerate Lib/symbol.py and/or Lib/token.py.
|
||
|
||
__ The parser module. Add some of your new syntax to test_parser,
|
||
bang on parsermodule.c until it passes.
|
||
|
||
__ The compiler package. A good test is to compile the standard
|
||
library and test suite with the compiler package and then check
|
||
it runs. You did add some of your new syntax to the test
|
||
suite, didn't you? There's a script in Tools/compiler that
|
||
does this.
|
||
|
||
__ If you've gone so far as to change the token structure of
|
||
Python, then the tokenizer library module will need to be
|
||
changed.
|
||
|
||
__ Certain changes may require tweaks to the library module
|
||
pycblr.
|
||
|
||
__ Jython too will need work, but I don't know what. Explanations
|
||
gratefully received.
|
||
|
||
|
||
References
|
||
|
||
[1] SF Bug #676521, parser module validation failure
|
||
http://www.python.org/sf/676521
|
||
|
||
|
||
Copyright
|
||
|
||
This document has been placed in the public domain.
|
||
|
||
|
||
|
||
Local Variables:
|
||
mode: indented-text
|
||
indent-tabs-mode: nil
|
||
sentence-end-double-space: t
|
||
fill-column: 70
|
||
End:
|