Re: Idea about recurse pattern matching (%r)

[Kenneth LO <kenlo88@...>]

On Tue, Nov 6, 2012 at 4:13 PM, Xavier Wang <weasley.wx@gmail.com> wrote:

now Lua don't support ?,*,+,- on a so-called sub-pattern, but from the
source, to add this support is easy: we can add a special %r (means
recurse) modifier, so as:
("catcatcat"):match "%r(cat)+"
returns
catcatcat

I do a recursion.

function checkformat(what)

-- Lua cannot handle repeated multibyte patterns

-- i.e. [Ab]+ does not match AbAbAb...

-- this situation is handled by a recursive function

  if what=='' then return 'true' end

  _,_,mm,xx = string.find(what, "^([%u][%l]+)(%a*)")

  if mm then return(checkformat(xx))

  else

     return nil

  end

end