vim script to fold code blocks using regexp

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• see all virtual functions :ZFFoldBlock //virtual/

  

• filter out all comments :ZFFoldBlock /^[ \t]*#//

  

• fold by xml tags :ZFFoldBlock /<([a-z0-9_:\.]+)/<\/\l1>|\/>/ (with othree/eregex.vim)

  

1. use Vundle or any other plugin manager is recommended

   Plugin 'ZSaberLv0/ZFVimFoldBlock'
   

   when othree/eregex.vim installed (recommended), perl style regexp would be used instead of vim style

   Plugin 'othree/eregex.vim'
   

2. foldmethod must be set to manual

   set foldmethod = manual
   

   by default, foldmethod would be set to manual when ZFFoldBlock called, you may disable it by let g:ZFVimFoldBlock_resetFoldmethodWhenUse=0

3. foldminlines recommended set to 0, which allow fold even for single line

   set foldminlines=0
   

   by default, foldminlines would be set to 0 when ZFFoldBlock called, you may disable it by let g:ZFVimFoldBlock_resetFoldminlinesWhenUse=0

4. recommended to have these key map:

   nnoremap ZB q::call ZF_FoldBlockTemplate()<cr>
   nnoremap ZF :ZFFoldBlock //<left>
   

5. or, use the functions directly:

   " fold by begin and end regexp
   :ZFFoldBlock /begin_regexp/end_regexp/
   
   " same as :ZFFoldBlock /regexp//
   :ZFFoldIfMatch regexp
   
   " same as :ZFFoldBlock //regexp/
   :ZFFoldIfNotMatch regexp
   

you may :call ZF_FoldBlockHelp() to show sample at any time

• /{/}/ : normal block mode

  {
      in fold 1
      {
          in fold 2
      }
      in fold 1
  }
  

• /rem// : fold if match

  rem in fold
  rem in fold
  

• //rem/ : fold if not match

  in fold
  in fold
  rem not in fold
  rem not in fold
  

• /tag/tag/ : single tag mode

  tag
      in fold 1
  tag
  not in fold
  tag
      in fold 2
  tag
  

use vim's regexp by default, see :h magic

if you have othree/eregex.vim installed, then perl style regexp would be used instead

you may force disable it by let g:ZFVimFoldBlock_disableE2v = 1

• typical advanced usage:

  " fold comments accorrding to file type
  function! ZF_Plugin_ZFVimFoldBlock_comment()
      let expr='\(^\s*\/\/\)'
      if &filetype=='vim'
          let expr.='\|\(^\s*"\)'
      endif
      if &filetype=='c' || &filetype=='cpp'
          let expr.='\|\(^\s*\(\(\/\*\)\|\(\*\)\)\)'
      endif
      if &filetype=='make'
          let expr.='\|\(^\s*#\)'
      endif
      let disableE2vSaved = g:ZFVimFoldBlock_disableE2v
      let g:ZFVimFoldBlock_disableE2v = 1
      call ZF_FoldBlock("/" . expr . "//")
      let g:ZFVimFoldBlock_disableE2v = disableE2vSaved
      echo "comments folded"
  endfunction
  nnoremap ZC :call ZF_Plugin_ZFVimFoldBlock_comment()<cr>
  

• calling ZFFoldBlock would append fold instead of replace, before using the function, you may want to remove all fold by zE or zD manually

• when fold with /expr_l/expr_r/ format, there's a special pattern for expr_r to reference submatches in expr_l (similar to :h /\1), the pattern format is \lN, where N is 1~9

  for example, /<([a-z]+)>/</\l1>/ would result:

  xxx   // not in fold
  <aa>  // in fold
    xxx // in fold
  </aa> // in fold
  xxx   // not in fold