[py] indent is off on enter with cursor in front of line

[alur]

def foo():
  if 1 == 1:
    bar()
  if 2 == 2:
    foo()

Enter when the cursor is in front of "if 2 == 2:" moves the line to column 0. Enter in front of "if 1 == 1:" works as expected.

[jerkyfeep]

Can someone take a look at this issue? It's terribly annoying, especially in constructions like:

class MyClass:
  def foo(self):
    if True:
      if True:
        if True:
          bar()   # if hit enter in front of this line - everything works as expected
          if True:   # if you hit enter in front of this line - it moves the line to column 0
            pass

and you have to figure out how many levels of indentation there was.

[marijnh]

It seems hard to provide automatic indentation for Python that always works—since the code structure doesn't determine a proper indentation, but rather the indentation determines the code structure. After the enter press in the initial example, you have the code...

def foo():
  if 1 == 1:
    bar()
  
if 2 == 2:
    foo()

... which is a perfectly reasonable Python program, so the indentation-computing function will, using the parser's knowlege of where the second if is (now) in the tree, decide that 0 is the appropriate indentation. That might even be the user's intention.

I can imagine a system doing more intention-guessing from the actual enter key event, but that's not how CodeMirror's built-in autoindentation works—that first inserts a newline, then computes an indentation for the new line, and then inserts or removes whitespace to match.

[jerkyfeep]

It seems hard to provide automatic indentation for Python that always works—since the code structure doesn't determine a proper indentation, but rather the indentation determines the code structure. After the enter press in the initial example, you have the code...

def foo():
  if 1 == 1:
    bar()
  
if 2 == 2:
    foo()

... which is a perfectly reasonable Python program, so the indentation-computing function will, using the parser's knowlege of where the second if is (now) in the tree, decide that 0 is the appropriate indentation. That might even be the user's intention.

Can we save the previous position of a code block in the tree before inserting a new line and then just preserve it? If there is no other suggestions from the indentation-computing function.