s               = ws! (Def+/ws) ws!

Def = Id "(" (Id+/comma) "->" (Id+/comma) ")" "=" Exprs /ws

Exprs =
  Exprs:: Decl */ ws
          ws!
          ((Expr +/ ws) +/ semicolons)

Decl = Id   ^"::" ShipName  /ws

Expr = "{" Exprs "}"        /ws
     | (Literal|Port)     ^"-->"              Ports /ws
     | (Literal|Port)     ^"+->"              Ports /ws
     | (Literal|Port) ws! ^"-[" Int "]->" ws! Ports
     | (Literal|Port)     ^"-[*]->"           Ports /ws
     | ^"while" Cond Expr /ws
//   | "if" "then" "else"

CondOp = ^"==" | ^"!=" | ^">" | ^">=" | ^"<" | ^"<="
Cond   = Cond:: Port CondOp Int /ws

Ports    = ";":: Port +/ semicolon
         > ",":: Port +/ comma
Port     = "Port":: Id
         | "Port":: Id "." Id

Literal  = Int | ^"{" Int +/ comma "}" /ws
Int      = [\-0-9]++
ShipName = "":: [A-Z] [a-zA-Z0-9_]*
Id       = "":: [a-z] [a-zA-Z0-9_]*

Comment    = "//" (~eol)* eol!
           | "/*" (any* &~ (any*! "*/" any*!)) "*/"
ws         = (wsc | Comment)* -> ~wsc
eol        = [\r\n]
wsc        = [\r\n ] | \{ | \}
comma      = ws! "," ws!
semicolon  = ws! ";" ws!
semicolons = ws! ";;" ws!
any        = ~[]