Error on opening a file with match / case

[aaannestad]

This version of semshi throws an error when trying to open a file involving Python 3.10's match/case syntax. (I've switched to this from the original numirias/semshi because that just treats a use of match as an error in your Python code!) It's possible this is my fault for switching from numirias/semshi incorrectly, but all other Python files seem to open just fine - it's only files using the match/case syntax that throw an error.

Steps to reproduce:

• Save a file containing the following code:

def test(arg):
    match arg:
        case True:
            print('worked')
        case False:
            print('didnt work')

test(False)

• Reopen the test file with neovim

You should get a large error like the following (probably not partially in Norwegian, but you get the idea):

Feil oppdaget under prosessering av BufReadPost Autokommandoer for "*":
Error executing lua callback: /usr/share/nvim/runtime/filetype.lua:24: Error executing lua: /usr/share/nvim/runtime/filetype.lua:25: BufReadPost Autokommandoer for "*"..FileType Autokommandoer for "*"..function <SNR>12_filetype_changed[4]..remote#define#CommandBootstrap[5]..remote#define#request, line 2: Vim(let):Error invoking '/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi:command:Semshi' on channel 3 (pytho
n3-rplugin-host):Feil oppdaget under prosessering av BufReadPost Autokommandoer for "*":
Error executing lua callback: /usr/share/nvim/runtime/filetype.lua:24: Error executing lua: /usr/share/nvim/runtime/filetype.lua:25: BufReadPost Autokommandoer for "*"..FileType Autokommandoer for "*"..function <SNR>12_filetype_changed[4]..remote#define#CommandBootstrap[5]..remote#define#request, line 2: Vim(let):Error invoking '/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi:command:Semshi' on channel 3 (pytho
n3-rplugin-host):
error caught in request handler '/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi:command:Semshi [['enable']]':
Traceback (most recent call last):
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/plugin.py", line 151, in cmd_semshi
    func(self, *args[1:])
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/plugin.py", line 35, in wrapper
    func(self, *args, **kwargs)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/plugin.py", line 174, in enable
    self.highlight()
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/plugin.py", line 35, in wrapper
    func(self, *args, **kwargs)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/plugin.py", line 197, in highlight
    self._cur_handler.update(force=True, sync=True)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/handler.py", line 71, in update
    self._update_step(force=force, sync=True)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/util.py", line 19, in wrapper
    res = func(*args, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/handler.py", line 163, in _update_step
    add, rem = self._parser.parse(code, force)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/util.py", line 19, in wrapper
    res = func(*args, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/parser.py", line 47, in parse
    return self._parse(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/parser.py", line 68, in _parse
    new_nodes = self._make_nodes(code, new_lines, change_lineno)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/parser.py", line 108, in _make_nodes
    return visitor(lines, symtable_root, ast_root)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/util.py", line 19, in wrapper
    res = func(*args, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/visitor.py", line 50, in visitor
    visitor.visit(ast_root)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/visitor.py", line 130, in visit
    self._iter_node(node)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/visitor.py", line 413, in _iter_node
    self.visit(item)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/visitor.py", line 120, in visit
    self._iter_node(node)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/visitor.py", line 413, in _iter_node
    self.visit(item)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/visitor.py", line 135, in visit
    self._iter_node(node)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/visitor.py", line 413, in _iter_node
    self.visit(item)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/visitor.py", line 135, in visit
    self._iter_node(node)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/visitor.py", line 417, in _iter_node
    self.visit(value)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/visitor.py", line 135, in visit
    self._iter_node(node)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/visitor.py", line 417, in _iter_node
    self.visit(value)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/visitor.py", line 135, in visit
    self._iter_node(node)
  File "/home/[USER]/.local/share/nvim/plugged/semshi/rplugin/python3/semshi/visitor.py", line 404, in _iter_node
    for field in node._fields:
                 ^^^^^^^^^^^^
AttributeError: 'bool' object has no attribute '_fields'
stack traceback:
        [C]: in function 'nvim_cmd'
        /usr/share/nvim/runtime/filetype.lua:25: in function </usr/share/nvim/runtime/filetype.lua:24>
        [C]: in function 'nvim_buf_call'
        /usr/share/nvim/runtime/filetype.lua:24: in function </usr/share/nvim/runtime/filetype.lua:10>
stack traceback:
        [C]: in function 'nvim_buf_call'
        /usr/share/nvim/runtime/filetype.lua:24: in function </usr/share/nvim/runtime/filetype.lua:10>
Trykk ENTER eller skriv kommando for å fortsette

You can bypass the error to continue editing the file, but the highlighting rules aren't fully operational.

If you replace the match/case syntax in the test code with an if/else statement, the file should open normally.

[wookayin]

I can confirm the bug, reproducible in both python3.10 and python3.11.

[wookayin]

Fixed the error but I find it's not enough -- semantic highlight isn't quite correct. I will fix that too.

def test_match(arg, foo=False):
    match arg:
        case 42:
            print('constant')
        case foo:
        # case arg:
            print('arbitrary matching')