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(** Copyright 2025-2026, Ram Prosad Chandra Sutra Dhar *)
(** SPDX-License-Identifier: LGPL-3.0-or-later *)
open EChandraSutraDhar_lib
open Inferencer
open Ast
let pretty_printer_parse_and_infer s =
match Parser.parse s with
| Ok parsed ->
(match run_infer parsed with
| Ok env ->
let filtered_env =
Base.Map.filter_keys env ~f:(fun key ->
not (List.mem key [ "print_int"; "print_endline"; "print_bool" ]))
in
Base.Map.iteri filtered_env ~f:(fun ~key ~data:(S (_, ty)) ->
Format.printf "val %s: %a" key pp_ty ty)
| Error e -> Format.printf "Infer error. %a\n" pp_error e)
| Error e -> Format.printf "Parsing error. %s\n" e
;;
let pretty_printer_parse_and_infer_simple s =
match Parser.parse s with
| Ok parsed ->
(match parsed with
| [ SEval expr ] ->
(match infer_simple_expression expr with
| Ok ty -> Format.printf "%a\n" pp_ty ty
| Error e -> Format.printf "Infer error. %a\n" pp_error e)
| _ ->
Format.printf
"Expected a single expression, but got a program with multiple structures.\n")
| Error e -> Format.printf "Parsing error. %s\n" e
;;
let%expect_test "int literal" =
pretty_printer_parse_and_infer_simple "42";
[%expect {| int |}]
;;
let%expect_test "bool literal" =
pretty_printer_parse_and_infer_simple "true";
[%expect {| bool |}]
;;
(* Variables and let bindings *)
let%expect_test "simple let" =
pretty_printer_parse_and_infer "let x = 5";
[%expect {| val x: int |}]
;;
let%expect_test "tuple creation" =
pretty_printer_parse_and_infer_simple "(1, true, \"hello\")";
[%expect {| (int * bool * string) |}]
;;
let%expect_test "test_binary_oper" =
pretty_printer_parse_and_infer_simple "10/2 + 56*2 - 10 / 10 / 20 + 666 - 777 + 1";
[%expect {|int|}]
;;
let%expect_test "test_bool" =
pretty_printer_parse_and_infer_simple "false";
[%expect {|bool|}]
;;
let%expect_test "test_string" =
pretty_printer_parse_and_infer_simple "\"I like OCaml\" ";
[%expect {|string|}]
;;
let%expect_test "test_option" =
pretty_printer_parse_and_infer_simple "Some 10";
[%expect {|int option|}]
;;
let%expect_test "test_binary_oper_and_arg" =
pretty_printer_parse_and_infer_simple "fun x -> x * 69 + 100 - 201 / 777";
[%expect {|int -> int|}]
;;
let%expect_test "test_rec" =
pretty_printer_parse_and_infer "let rec func arg = func arg";
[%expect {|val func: '1 -> '2|}]
;;
let%expect_test "test_func_apply_some_args" =
pretty_printer_parse_and_infer "let func a1 a2 a3 = a1 a2 a3";
[%expect {|val func: ('1 -> '2 -> '4) -> '1 -> '2 -> '4|}]
;;
let%expect_test "test_tuple" =
pretty_printer_parse_and_infer_simple "fun x y z -> (x + 10, y / 2 , z)";
[%expect {|int -> int -> '2 -> (int * int * '2)|}]
;;
let%expect_test "test_list" =
pretty_printer_parse_and_infer "let arr = [1;2;3]";
[%expect {|val arr: int list|}]
;;
let%expect_test "test_binary_oper" =
pretty_printer_parse_and_infer "let is_above_10 x = if x > 10 then true else false ";
[%expect {|val is_above_10: int -> bool|}]
;;
let%expect_test "test_binary_oper" =
pretty_printer_parse_and_infer "let is_above_10 x = x > 10";
[%expect {|val is_above_10: int -> bool|}]
;;
let%expect_test "test_factorial" =
pretty_printer_parse_and_infer "let rec fac n = if n < 2 then 1 else n * fac (n - 1)";
[%expect {|val fac: int -> int|}]
;;
let%expect_test "test_nested_list_function" =
pretty_printer_parse_and_infer "let f x = [ [x; x]; [x] ]";
[%expect {|val f: '0 -> '0 list list|}]
;;
let%expect_test "test_nested_option_function" =
pretty_printer_parse_and_infer "let f x = Some x";
[%expect {|val f: '0 -> '0 option|}]
;;
let%expect_test "test_fibonacci" =
pretty_printer_parse_and_infer
"let rec fibo n = if n < 2 then 1 else fibo(n - 1) + fibo(n - 2)";
[%expect {|val fibo: int -> int|}]
;;
let%expect_test "test_unbound_var" =
pretty_printer_parse_and_infer "let f = x";
[%expect {|Infer error. Unbound variable 'x'.|}]
;;
let%expect_test "test_annotate" =
pretty_printer_parse_and_infer "let sum = fun (x : int) (y : int) -> x + y";
[%expect {|val sum: int -> int -> int|}]
;;
let%expect_test "test_annotate_fac" =
pretty_printer_parse_and_infer
"let rec fac = fun (n : int) (acc : int) -> if n < 2 then acc else fac (n-1) (acc * \
n);;";
[%expect {|val fac: int -> int -> int|}]
;;
let%expect_test "test_annotate_error" =
pretty_printer_parse_and_infer "let sum (x : int) (y : string) = x + y";
[%expect {|Infer error. Failed to unify types: string and int.|}]
;;
let%expect_test "test_unification_types" =
pretty_printer_parse_and_infer "fun x -> x + true";
[%expect {|Infer error. Failed to unify types: bool and int.|}]
;;
let%expect_test "test_option_type_error" =
pretty_printer_parse_and_infer
"let f x = Some (x + 1) in let g y = Some (y && true) in f = g";
[%expect {|Infer error. Failed to unify types: bool and int.|}]
;;