Crate io_prompt_prototype

A prototype for io::prompt, io::promptln, and io::read_line.

Examples

use io_prompt_prototype::{prompt, promptln};

let num: u16 = prompt!("What's your favorite number? >").parse()?;
println!("Oh, cool: {}!", num);

let variable = "snack";
let res = promptln!("What's your favorite {}? >", variable);
println!("We love {} too!", res);

Design Considerations

A survey of existing prompt functions can be found here This library makes several tradeoffs in its design:

• Just like the std::io::println! family of macros, the prompt macros panic in the case of an error.
• The prompt macros don’t support parsing of values in-place. Users are encouraged to .parse instead.
• The prompt family of macros only support reading a single line at the time and assigning it to a value.
• The prompt family of macros doesn’t support rich input types such as passwords or dropdowns. This functionality is expected to be provided through crates.io.

This library is split into two parts: a convenient read_line function which is a shorthand for calling Stdin::read_line and reading into a new string. And the prompt! family of macros which support reading from writing to stdout/stderr, and reading a value from stdin.

The focus for the prompt family of macros is on simplicity: its goal is to make it convenient to write quick prompts inside Rust programs in a way that feels similar to using println!. It does not try and cover parsing rules by introducing a new DSL. Such a DSL almost certainly needs to have regex-like capabilities, and would be nearly impossible to stabilize.

Macros

eprompt

Prints to the standard error. Then reads a line of input.

epromptln

Prints to the standard error, with a newline. Then reads a line of input.

prompt

Prints to the standard output. Then reads a line of input.

promptln

Prints to the standard output, with a newline. Then reads a line of input.

Functions

read_line

Reads a line of input from stdin.