Multiline Input #209
Description
I want to implement a prompt where the user can enter arbitrary text, including multiple lines. From what I can see, most prompts would rely on parsing the syntax of the entered text to determine whether the input is complete or whether to ask for more text when a line is entered. However, I see no way of doing this with unstructured, arbitrary text. Here, I would have to rely on the user to signal when the input is complete.
I could of course make up some contrived scheme like "if the last character of the user input line is \, then it means they are asking for another line", but that kind of undermines the goal of enabling truly arbitrary text entry by the user.
In some user interfaces, this is done for example via "enter" signaling complete input, and "shift-enter" signaling partial input with a request for another input line. As far as I can tell, this is not currently possible with Haskeline, or am I missing something?