InputError

Built-in class · Extends RuntimeError

An InputError is what Emerald raises when a program asks for a line of input and can’t get one: the input has ended, as when it comes from a file that ran out, or the line isn’t valid text. It comes from input and from the questions Console asks.

try {
    const name = input("What is your name? ")
    print("Hello, #{name}!")
}
catch error: InputError {
    print("No answer came: #{error.message}")
}

Output

What is your name? No answer came: `input` reached the end of the input

When someone is typing at a keyboard, input doesn’t end until they close it, so the usual place to meet this error is a program whose input is a file or another program’s output. To read until the input runs out without an error, use input_maybe, which gives nothing at the end.

An InputError is a RuntimeError, so catch error: RuntimeError catches it too.

message: String

What went wrong, in words, naming the function that was reading.

What the messages say

Message	When
`input` reached the end of the input	There is no more input to read
the line read by input is not valid UTF-8 text	The line holds bytes that aren’t text; this is raised by input_maybe too

The questions Console asks name themselves in the first message, as in `Console.ask` reached the end of the input.