CODEWITHSUNDEEP
vim
CornSmith
CornSmith

Reputation: 2037

Fold up to the fold start, instead of the indent start

I use foldmethod=indent and when I fold code like this:

def cake():
    #cake!
    print( "cake" )
    print( "for" )
    print( "you" )

I see

def cake():
    #cake!
    print( "cake" ) +++ 3 lines folded

but I want to see

def cake(): +++ 5 lines folded

Is there a way to do fold up to the first line (def cake():) like this?

Upvotes: 1

Views: 111

Answers (2)

CornSmith
CornSmith

Reputation: 2037

I solved this using this tutorial.

This is the finished bunch of functions: 

fu! Indent_level(lnum)
  return indent(a:lnum) / &shiftwidth
  endfunction

fu! Next_non_blank_line(lnum)
  let numlines = line('$')
  let current = a:lnum + 1

  while current <= numlines
    if getline(current) =~? '\v\S'
      return current
      endif
    let current += 1
    endwhile
  return -2
  endfunction

fu! Custom_fold_expr(lnum)
  if getline(a:lnum) =~? '\v^\s*$'
    return '-1'
    endif

  let this_indent = Indent_level(a:lnum)
  let next_indent = Indent_level(Next_non_blank_line(a:lnum))

  if next_indent == this_indent
    return this_indent
  elseif next_indent < this_indent
    return this_indent
  elseif next_indent > this_indent
    return '>' . next_indent
    endif
  endf

set foldexpr=Custom_fold_expr(v:lnum)
foldmethod=expr

Please don't edit the indentation of the "end" markers on this post, it looks gorgeous after you put this in your vimrc.

Upvotes: 1

echristopherson
echristopherson

Reputation: 7074

Chapters 48 and 49 of Learn Vimscript the Hard Way talk about how to do that, using foldmethod=expr instead of indent. Basically you need to make a custom ftplugin and put a folding script in it; the script contains functions used to determine what fold level different lines should have.

As luck would have it, the example code given in those two chapters is for the Potion language which, like Python, is whitespace-sensitive, so it should be pretty easy to adapt it to Python. Since Vim already comes with a Python ftplugin, I think you can put the folding script described on the site into .vim/after/ftplugin/python instead of .vim/ftplugin/potion.

Upvotes: 2

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