You're seeing just the function next_char, go back to Ergo.Context module for more information.
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Reads the next character from the input of the passed in Context.

If the input is empty returns status: {:error, :unexpected_eoi}.

Otherwise returns a new Context setting ast to the character read and incrementing positional variables such as index, line, and column appropriately.


iex> context = Context.next_char("")) iex> assert %Context{status: {:error, [{:unexpected_eoi, {1, 1}, "Unexpected end of input"}] }} = context

iex> context = Context.next_char("Hello World")) iex> assert %Context{status: :ok, input: "ello World", ast: ?H, index: 1, line: 1, col: 2} = context