Newb's FSM troubles, part one.

[frankshank]

I'm trying to detect users mentioned in a string. Users have an "@"
before their name. Here's my current machine:

%{
  machine user_parser;
  action mark { mark = p; }
  action print_user { puts("user: #{data[mark..p]}"); }
  user_name = (lower . (lower | digit)*);
  user_tag = ("@">mark . user_name) % print_user;
  random_text = (0x20..0x3f | 0x41..0x7e)+; # all ascii, except for
'@'
  main := (random_text | user_tag)*;
}%%

When I run this against "@u1 @u2", i see this output:

user: @u1
user: @u1
user: @u2