Fix issues with dialyzer infinite loop (#7993)

Signed-off-by: José Valim <jose.valim@plataformatec.com.br>

Author: michalmuskala

lib/elixir/lib/calendar/date.ex

@@ -263,24 +263,29 @@ defmodule Date do
   @spec from_iso8601(String.t(), Calendar.calendar()) :: {:ok, t} | {:error, atom}
   def from_iso8601(string, calendar \\ Calendar.ISO)
 
-  [match_date, guard_date, read_date] = Calendar.ISO.__match_date__()
-
-  def from_iso8601(unquote(match_date), calendar) when unquote(guard_date) do
-    {year, month, day} = unquote(read_date)
-
-    with {:ok, date} <- new(year, month, day, Calendar.ISO) do
-      convert(date, calendar)
+  def from_iso8601(<<?-, rest::binary>>, calendar) do
+    with {:ok, %{year: year} = date} <- raw_from_iso8601(rest, calendar) do
+      {:ok, %{date | year: -year}}
     end
   end
 
-  def from_iso8601(<<?-, next, rest::binary>>, calendar) when next != ?- do
-    with {:ok, %{year: year} = date} <- from_iso8601(<<next>> <> rest, calendar) do
-      {:ok, %{date | year: -year}}
-    end
+  def from_iso8601(<<rest::binary>>, calendar) do
+    raw_from_iso8601(rest, calendar)
   end
 
-  def from_iso8601(<<_::binary>>, _calendar) do
-    {:error, :invalid_format}
+  [match_date, guard_date, read_date] = Calendar.ISO.__match_date__()
+
+  defp raw_from_iso8601(string, calendar) do
+    with unquote(match_date) <- string,
+         true <- unquote(guard_date) do
+      {year, month, day} = unquote(read_date)
+
+      with {:ok, date} <- new(year, month, day, Calendar.ISO) do
+        convert(date, calendar)
+      end
+    else
+      _ -> {:error, :invalid_format}
+    end
   end
 
   @doc """

lib/elixir/lib/calendar/datetime.ex

@@ -511,8 +511,8 @@ defmodule DateTime do
   [match_time, guard_time, read_time] = Calendar.ISO.__match_time__()
 
   def from_iso8601(string, calendar \\ Calendar.ISO) when is_binary(string) do
-    with <<unquote(match_date), sep, unquote(match_time), rest::binary>>
-         when unquote(guard_date) and sep in @sep and unquote(guard_time) <- string,
+    with <<unquote(match_date), sep, unquote(match_time), rest::binary>> <- string,
+         true <- unquote(guard_date) and sep in @sep and unquote(guard_time),
          {microsecond, rest} <- Calendar.ISO.parse_microsecond(rest),
          {offset, ""} <- Calendar.ISO.parse_offset(rest) do
       {year, month, day} = unquote(read_date)

lib/elixir/lib/calendar/naive_datetime.ex

@@ -495,19 +495,23 @@ defmodule NaiveDateTime do
   @spec from_iso8601(String.t(), Calendar.calendar()) :: {:ok, t} | {:error, atom}
   def from_iso8601(string, calendar \\ Calendar.ISO)
 
-  def from_iso8601(<<?-, next, rest::binary>>, calendar) when next != ?- do
-    with {:ok, %{year: year} = naive_datetime} <- from_iso8601(<<next>> <> rest, calendar) do
+  def from_iso8601(<<?-, rest::binary>>, calendar) do
+    with {:ok, %{year: year} = naive_datetime} <- raw_from_iso8601(rest, calendar) do
       {:ok, %{naive_datetime | year: -year}}
     end
   end
 
+  def from_iso8601(<<rest::binary>>, calendar) do
+    raw_from_iso8601(rest, calendar)
+  end
+
   @sep [?\s, ?T]
   [match_date, guard_date, read_date] = Calendar.ISO.__match_date__()
   [match_time, guard_time, read_time] = Calendar.ISO.__match_time__()
 
-  def from_iso8601(string, calendar) when is_binary(string) do
-    with <<unquote(match_date), sep, unquote(match_time), rest::binary>>
-         when unquote(guard_date) and sep in @sep and unquote(guard_time) <- string,
+  defp raw_from_iso8601(string, calendar) do
+    with <<unquote(match_date), sep, unquote(match_time), rest::binary>> <- string,
+         true <- unquote(guard_date) and sep in @sep and unquote(guard_time),
          {microsec, rest} <- Calendar.ISO.parse_microsecond(rest),
          {_offset, ""} <- Calendar.ISO.parse_offset(rest) do
       {year, month, day} = unquote(read_date)

lib/elixir/lib/calendar/time.ex

@@ -217,14 +217,19 @@ defmodule Time do
   @spec from_iso8601(String.t(), Calendar.calendar()) :: {:ok, t} | {:error, atom}
   def from_iso8601(string, calendar \\ Calendar.ISO)
 
-  def from_iso8601(<<?T, h, rest::binary>>, calendar) when h in ?0..?9 do
-    from_iso8601(<<h, rest::binary>>, calendar)
+  def from_iso8601(<<?T, rest::binary>>, calendar) do
+    raw_from_iso8601(rest, calendar)
+  end
+
+  def from_iso8601(<<rest::binary>>, calendar) do
+    raw_from_iso8601(rest, calendar)
   end
 
   [match_time, guard_time, read_time] = Calendar.ISO.__match_time__()
 
-  def from_iso8601(string, calendar) do
-    with <<unquote(match_time), rest::binary>> when unquote(guard_time) <- string,
+  defp raw_from_iso8601(string, calendar) do
+    with <<unquote(match_time), rest::binary>> <- string,
+         true <- unquote(guard_time),
          {microsec, rest} <- Calendar.ISO.parse_microsecond(rest),
          {_offset, ""} <- Calendar.ISO.parse_offset(rest) do
       {hour, min, sec} = unquote(read_time)