template<class keywords, class action, class end = pegtl::space>
tk::grm::scan_until struct

Scan input padded by blank at left and space at right and if it matches 'keywords', apply 'action'.

This version uses an additional custom end rule. As opposed to scan, this rule allows an additional end-rule until which parsing is continued. The additional custom end-rule is OR'd to pegtl::space.