glisp

-module(glisp@repl).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([main_repl/0]).

-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.

-file("src/glisp/repl.gleam", 25).
-spec repl_loop(gleam@dict:dict(binary(), glisp@ast:expr())) -> nil.
repl_loop(Env) ->
    In = gleam@result:unwrap(input_ffi:input(<<"> "/utf8>>), <<""/utf8>>),
    case gleam@string:trim(In) of
        <<"exit"/utf8>> ->
            gleam_stdlib:println(<<"Goodbye!"/utf8>>),
            nil;

        <<""/utf8>> ->
            repl_loop(Env);

        In@1 ->
            Res = begin
                _pipe = glisp@tokenizer:tokenize(In@1),
                _pipe@1 = glisp@parser:parse(_pipe),
                gleam@result:then(
                    _pipe@1,
                    fun(Expr) -> glisp@eval:eval(Expr, Env) end
                )
            end,
            case Res of
                {ok, Value} ->
                    gleam_stdlib:println(glisp@ast:expr_to_string(Value));

                {error, Err} ->
                    gleam_stdlib:println(<<"Error: "/utf8, Err/binary>>)
            end,
            repl_loop(Env)
    end.

-file("src/glisp/repl.gleam", 17).
?DOC(
    " Starts an interactive REPL (Read-Eval-Print Loop) for the GLisp interpreter.\n"
    "\n"
    " This function initializes the standard environment, displays a welcome message,\n"
    " and allows users to input Lisp expressions for immediate evaluation.\n"
    " The loop continues until the user types 'exit'.\n"
).
-spec main_repl() -> nil.
main_repl() ->
    gleam_stdlib:println(
        <<"Welcome to GLisp - A Lisp interpreter in Gleam!"/utf8>>
    ),
    gleam_stdlib:println(
        <<"Type expressions to evaluate, or 'exit' to quit."/utf8>>
    ),
    Env = glisp@stdlib:standard_env(),
    repl_loop(Env).