my $DSL = <<'DSL';
:default ::= action => ::first
lexeme default = latm => 1

start ::= sexp

sexp ::= list
       | atom

list ::= LPAREN elements RPAREN action => Sexp::Tiny::Actions::do_list
elements ::= element* action => Sexp::Tiny::Actions::do_elements
element ::= sexp

atom ::= string
       | symbol

string ::= DQUOTE string_chars DQUOTE action => Sexp::Tiny::Actions::do_string
         | DQUOTE DQUOTE            action => Sexp::Tiny::Actions::do_empty_string

string_chars ::= string_char+ action => Sexp::Tiny::Actions::do_join
string_char  ::= STRCHAR

DQUOTE  ~ '"'
STRCHAR ~ [^"]


symbol ::= symbol_chars action => Sexp::Tiny::Actions::do_symbol
symbol_chars ::= symbol_char+ action => Sexp::Tiny::Actions::do_join
symbol_char  ::= SYMCHAR
SYMCHAR ~ [^()\s"]

LPAREN ~ '('
RPAREN ~ ')'

:discard ~ WS
WS ~ [\s]+

DSL