fix: Add missing ? and ! characters to keyword character set

Keywords now properly support ? and ! characters as required by the
specification in docs/ptc-lisp-specification.md:1388.

Fixes: Missing keyword-char support for ? and ! in parser

Author: github-actions[bot]

lib/ptc_runner/lisp/parser.ex

@@ -95,7 +95,7 @@ defmodule PtcRunner.Lisp.Parser do
   # Keywords (no / allowed)
   keyword =
     ignore(string(":"))
-    |> ascii_string([?a..?z, ?A..?Z, ?0..?9, ?-, ?_], min: 1)
+    |> ascii_string([?a..?z, ?A..?Z, ?0..?9, ?-, ?_, ??, ?!], min: 1)
     |> reduce({ParserHelpers, :build_keyword, []})
 
   # Symbols (/ allowed for namespacing)

test/ptc_runner/lisp/parser_test.exs

@@ -34,6 +34,8 @@ defmodule PtcRunner.Lisp.ParserTest do
     test "keywords" do
       assert {:ok, {:keyword, :name}} = Parser.parse(":name")
       assert {:ok, {:keyword, :user_id}} = Parser.parse(":user_id")
+      assert {:ok, {:keyword, :empty?}} = Parser.parse(":empty?")
+      assert {:ok, {:keyword, :valid!}} = Parser.parse(":valid!")
     end
   end