The Terminal: Prompts

● Intermediate3 min

term.prompt, prompt_int, confirm and choose ask the user a question and give a typed answer.

use std.term

fn main() {
    const size = term.choose("Which size?", ["Small", "Medium", "Large"]) ?? 1
    if term.confirm("Order a {["Small", "Medium", "Large"][size]} tea?", default: false) {
        print("one tea coming up")
    } else {
        print("maybe later")
    }
}

kavach run confirm.kav

Which size?  1. Small  2. Medium  3. LargeChoose 1-3: Order a Large tea? [y/N] one tea coming up

Function	Gives
`term.prompt(question) -> String?`	Prints `question` and a space, and gives the line typed, or `none` at the end of input
`term.prompt_int(question) -> Int?`	Asks for a whole number: an answer that isn't one gets `Please type a whole number.` and the question again; `none` at the end of input
`term.prompt_float(question) -> Float?`	The same for a number (`2.5`, `3`), with `Please type a number.`
`term.prompt_secret(question) -> Secret?`	Asks for a password or a token, the typing not shown (`io.read_hidden`), and gives `Secret(text: …)`; `none` at the end of input
`term.confirm(question, default: Bool) -> Bool`	Asks a yes-or-no question, shown with `[y/N]` (or `[Y/n]` when `default` is `true`): `y` or `yes` gives `true`, `n` or `no` gives `false`, anything else, an empty line or the end of input gives `default`
`term.choose(question, options: [String]) -> Int?`	Prints `question` and the options, numbered from 1, and asks for a number: gives the index (from 0) of the option chosen, or `none` when the answer is not one of them

Prompts read standard input whether or not it is a terminal, so a script can answer them through a pipe, as this page did. See User Input for names, numbers and passwords.