Description

The readline module lets you await and read user input from a terminal in an easy and structured manner.

The module provides an easy way to prompt the user for questions or even make a REPL or an embedded console.

Usage:

import readline

mut r := readline.Readline{}
answer := r.read_line('hello: ')!
println(answer)

or just:

import readline { read_line }

input := read_line('What is your name: ')!
println('Your name is: ${input}')

fn read_line(prompt string) !string

read_line does the same as read_line_utf8 but returns user input as a string. (As opposed to []rune as returned by read_line_utf8). NOTE that this version of read_line is a standalone function without persistent functionalities (e.g. history).

fn read_line_utf8(prompt string) ![]rune

read_line_utf8 blocks execution in a loop and awaits user input characters from a terminal until EOF or Enter key is encountered in the input stream. read_line_utf8 returns the complete UTF-8 input line as an UTF-32 encoded []rune or an error if the line is empty. The prompt string is output as a prefix text for the input capturing. read_line_utf8 is the main method of the readline module and Readline struct. NOTE that this version of read_line_utf8 is a standalone function without persistent functionalities (e.g. history).

struct Readline {
pub mut:
	is_raw                 bool
	orig_termios           termios.Termios // Linux
	current                []rune          // Line being edited
	cursor                 int             // Cursor position
	overwrite              bool
	cursor_row_offset      int
	prompt                 string
	prompt_offset          int
	previous_lines         [][]rune
	skip_empty             bool // skip the empty lines when calling .history_previous()
	search_index           int
	is_tty                 bool
	last_prefix_completion []rune
	last_completion_offset int
	completion_list        []string
	completion_callback    fn (string) []string = unsafe { nil }
}

Readline is the key struct for reading and holding user input via a terminal.

import readline { Readline }

fn (mut r Readline) disable_raw_mode()

disable_raw_mode disables the raw mode of the terminal. For a description of raw mode please see the enable_raw_mode method.

fn (mut r Readline) enable_raw_mode()

enable_raw_mode enables the raw mode of the terminal. In raw mode all key presses are directly sent to the program and no interpretation is done. Please note that enable_raw_mode catches the SIGUSER (CTRL + C) signal. For a method that does please see enable_raw_mode_nosig.

fn (mut r Readline) enable_raw_mode_nosig()

enable_raw_mode_nosig enables the raw mode of the terminal. In raw mode all key presses are directly sent to the program and no interpretation is done. Please note that enable_raw_mode_nosig does not catch the SIGUSER (CTRL + C) signal as opposed to enable_raw_mode.

fn (r Readline) read_char() !int

read_char reads a single character.

fn (mut r Readline) read_line(prompt string) !string

read_line does the same as read_line_utf8 but returns user input as a string. (As opposed to []rune returned by read_line_utf8).

fn (mut r Readline) read_line_utf8(prompt string) ![]rune

read_line_utf8 blocks execution in a loop and awaits user input characters from a terminal until EOF or Enter key is encountered in the input stream. read_line_utf8 returns the complete UTF-8 input line as an UTF-32 encoded []rune or an error if the line is empty. The prompt string is output as a prefix text for the input capturing. read_line_utf8 is the main method of the readline module and Readline struct.