Top down iterator with mutable state

[boisgera]

State being the path handled by iter(..., path=True) ? The aim would be to be able to iterate the tree, change things and then adjust what should be iterated after the changes.

[TakodaS]

Just wondering if this is related to a problem I am having. I want to delete all citations in a latex document and use

for elt, path in pandoc.iter(doc, path=True):
        if isinstance(elt, Cite): 
              parent, index = path[-1]
              del parent[index]

Is this the correct way to delete elements by type? The script doesn't delete all the citations in a document, as it always seems to miss a few. I think deleting elements while passing through a list isn't a good idea. Maybe it would be better to get a collection of elements first then delete them all at the same time?

[boisgera]

Hi @TakodaS!

I think deleting elements while passing through a list isn't a good idea.

Exactly. That's the same issue for Python lists and Pandoc documents.

Maybe it would be better to get a collection of elements first then delete them all at the same time?

Yes, you can collect the location of every citation in the document

cites = [
    path[-1]
    for elt, path in pandoc.iter(doc, path=True)
    if isinstance(elt, Cite)
]

then delete them in a second pass in reverse order (otherwise you may invalidate the indices in the remaining locations !)

for parent, index in reversed(cites):
    del parent[index]

Does it work for you?

Cheers,

SB