Immutable

[cdonovick]

This is a bit janky I automatically rebuild python ast class tree in an immutable form.

It might be better to run _generate_immutable_ast in setup.py instead of shipping a prebuilt immutable_ast.py.

[cdonovick]

Coverage increased on last push I don't know why coveralls thinks it went down...

[cdonovick]

Another option would be to just use the generated code as a starting point which we edit from here out. I think this has a couple of advantages.

It would simplify the metaclass as it would not longer need to dynamically construct __setattr__, __delattr__, __hash__, __eq__, __ne__ as they could just be moved to immutable_ast.AST.

It would make the code more clean because the re-implementations of iter_child_nodes, NodeVisitor, etc... could check isinstance(node, AST) instead of isinstance(type(node), ImmutableMeta) as immutable_ast.AST would actually be visible.
see https://github.com/leonardt/ast_tools/blob/immutable/ast_tools/_immutable_ast.py#L32

The disadvantage would obviously be that it is tied to a specific python version.

A final option would be to specialize the generation of immutable.AST and template in everything including the metaclass and functions to achieve the outcome of the above without the manual effort. However, this would probably make maintenance somewhat more difficult as everything would be in strings instead of code.

[cdonovick]

The more I think about the more I think that dynamically generating immutable_ast.py is a good idea while certain passes may be tied to a specific version of the ast keeping ast_tools as agnostic to the version as possible seems like a good idea.

[cdonovick]

Okay I have generating ast_tools.immutable_ast in setup.py kinda. However, I don't think my current approach will work on pypi because I do not think util/ will exist in pypi and I don't know how to make it be there without installing it or putting everything in setup.py.

While I think it would be pretty cool to automatically build immutable_ast on the fly I think it will ultimately be a nightmare for maintenance. So I think it might be best to actually just track the file even though it is generated. If people want to use a version of the AST not in our pypi then they can just generate it themselves.

[cdonovick]

Another option is generate a bunch of versions and import the one we want.

package structure:

ast_tools/immutable_ast/__init__.py
ast_tools/immutable_ast/ast35.py
ast_tools/immutable_ast/ast36.py
ast_tools/immutable_ast/ast37.py
ast_tools/immutable_ast/ast38.py
...

ast_tools/immutable_ast/__init__.py:

if sys.version_info[:2] == (3, 5):
  from ast35 import *
elif sys.version_info[:2] == (3, 6)
  from ast36 import *
...

[leonardt]

Could this just be False?

[leonardt]

I guess this will try the other way (inverse) which may be okay too, this seems reasonable.

[leonardt]

😂

[leonardt]

LGTM