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|
module T = Types.Types
module Env =
Map.Make (
String
(*(struct
type t = Types.Symbol
let compare (Types.Symbol a) (Types.Symbol b) = compare a b
end)*)
)
let num_fun f = Types.fn
(function
| [(T.Int a); (T.Int b)] -> T.Int (f a b)
| _ -> raise (Invalid_argument "Numeric args required for this Mal builtin"))
let repl_env = ref (List.fold_left (fun a b -> b a) Env.empty
[ Env.add "+" (num_fun ( + ));
Env.add "-" (num_fun ( - ));
Env.add "*" (num_fun ( * ));
Env.add "/" (num_fun ( / )) ])
let rec eval_ast ast env =
match ast with
| T.Symbol { T.value = s } ->
(try Env.find s !env
with Not_found -> raise (Invalid_argument ("Symbol '" ^ s ^ "' not found")))
| T.List { T.value = xs; T.meta = meta }
-> T.List { T.value = (List.map (fun x -> eval x env) xs);
T.meta = meta }
| T.Vector { T.value = xs; T.meta = meta }
-> T.Vector { T.value = (List.map (fun x -> eval x env) xs);
T.meta = meta }
| T.Map { T.value = xs; T.meta = meta }
-> T.Map {T.meta = meta;
T.value = (Types.MalMap.fold
(fun k v m
-> Types.MalMap.add (eval k env) (eval v env) m)
xs
Types.MalMap.empty)}
| _ -> ast
and eval ast env =
let result = eval_ast ast env in
match result with
| T.List { T.value = ((T.Fn { T.value = f }) :: args) } -> (f args)
| _ -> result
let read str = Reader.read_str str
let print exp = Printer.pr_str exp true
let rep str env = print (eval (read str) env)
let rec main =
try
while true do
print_string "user> ";
let line = read_line () in
try
print_endline (rep line repl_env);
with End_of_file -> ()
| Invalid_argument x ->
output_string stderr ("Invalid_argument exception: " ^ x ^ "\n");
flush stderr
done
with End_of_file -> ()
|
