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|
let rec eval = function Ast.Int n -> n | Add (a, b) -> eval a + eval b
let info = Cmdliner.Cmd.info "calc"
let eval_lb lb =
let e = Parser.main Lexer.token lb in
Printf.printf "%d\n" (eval e)
let repl () =
while true do
Printf.printf ">> %!";
let lb = Lexing.from_channel Stdlib.stdin in
eval_lb lb
done
let term =
let open Cmdliner.Term.Syntax in
let+ expr_opt =
let open Cmdliner.Arg in
value & opt (some string) None & info [ "e" ]
in
match expr_opt with
| Some s -> eval_lb (Lexing.from_string s)
| None -> repl ()
let cmd = Cmdliner.Cmd.v info term
let main () = Cmdliner.Cmd.eval cmd |> Stdlib.exit
|
