lookahead

import sdpc.parsers;

// Accept "asdf" if followed by "g"
alias p = seq!(token!"asdf", lookahead!(token!"g"));
auto i = "asdfg";
auto r1 = p(i);
assert(r1.ok);
assert(r1.cont == "g", r1.cont);

i = "asdff";
auto r2 = p(i);
assert(!r2.ok);