Changes

lib/util/parser.ml

@@ -25,6 +25,13 @@ let integer =
  Int.of_string tokens
 ;;
 
+let signed_integer =
+ let open Syntax in
+ let%map sign = 1 <$ char '+' <|> (-1 <$ char '-') <|> return 1
+ and n = integer in
+ sign * n
+;;
+
 let parse_exn parser input =
  input |> parse_string ~consume:Prefix parser |> Result.ok_or_failwith
 ;;

lib/year2023/dune

@@ -1,8 +1,13 @@
 (library
  (name year2023)
  (libraries
+ angstrom
  core
+ ppx_jane
  re
  util)
+ (preprocess
+ (pps
+ ppx_jane))
  (flags
  -open Core))

test/util/dune

@@ -0,0 +1,9 @@
+(library
+ (name util_test)
+ (libraries
+ ppx_jane
+ year2022)
+ (inline_tests)
+ (preprocess
+ (pps
+ ppx_jane)))

test/util/parser_test.ml

@@ -0,0 +1,19 @@
+module P = Util.Parser
+
+let%expect_test "signed_integer works with positive signs" =
+ let result = P.parse_exn P.signed_integer "+10" in
+ Printf.printf "%i" result;
+ [%expect {| 10 |}]
+;;
+
+let%expect_test "signed_integer works with negative signs" =
+ let result = P.parse_exn P.signed_integer "-10" in
+ Printf.printf "%i" result;
+ [%expect {| -10 |}]
+;;
+
+let%expect_test "signed_integer works with no signs" =
+ let result = P.parse_exn P.signed_integer "10" in
+ Printf.printf "%i" result;
+ [%expect {| 10 |}]
+;;