75 lines
2.6 KiB
V
75 lines
2.6 KiB
V
// Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
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// Use of this source code is governed by an MIT license
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// that can be found in the LICENSE file.
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//
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// TODO Windows version needs to be implemented.
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// Will serve as more advanced input method
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// based on the work of https://github.com/AmokHuginnsson/replxx
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//
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module readline
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import os
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// Only use standard os.get_line
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// Need implementation for readline capabilities
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//
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// read_line_utf8 blocks execution in a loop and awaits user input
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// characters from a terminal until `EOF` or `Enter` key is encountered
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// in the input stream.
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// read_line_utf8 returns the complete input line as an UTF-8 encoded `ustring` or
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// an error if the line is empty.
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// The `prompt` `string` is output as a prefix text for the input capturing.
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// read_line_utf8 is the main method of the `readline` module and `Readline` struct.
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pub fn (mut r Readline) read_line_utf8(prompt string) ?ustring {
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r.current = ''.ustring()
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r.cursor = 0
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r.prompt = prompt
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r.search_index = 0
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if r.previous_lines.len <= 1 {
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r.previous_lines << ''.ustring()
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r.previous_lines << ''.ustring()
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} else {
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r.previous_lines[0] = ''.ustring()
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}
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print(r.prompt)
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r.current = os.get_raw_line().ustring()
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r.previous_lines[0] = ''.ustring()
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r.search_index = 0
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if r.current.s == '' {
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return error('empty line')
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}
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return r.current
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}
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// read_line does the same as `read_line_utf8` but returns user input as a `string`.
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// (As opposed to `ustring` returned by `read_line_utf8`).
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pub fn (mut r Readline) read_line(prompt string) ?string {
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s := r.read_line_utf8(prompt) ?
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return s.s
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}
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// read_line_utf8 blocks execution in a loop and awaits user input
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// characters from a terminal until `EOF` or `Enter` key is encountered
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// in the input stream.
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// read_line_utf8 returns the complete input line as an UTF-8 encoded `ustring` or
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// an error if the line is empty.
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// The `prompt` `string` is output as a prefix text for the input capturing.
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// read_line_utf8 is the main method of the `readline` module and `Readline` struct.
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// NOTE that this version of `read_line_utf8` is a standalone function without
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// persistent functionalities (e.g. history).
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pub fn read_line_utf8(prompt string) ?ustring {
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mut r := Readline{}
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s := r.read_line_utf8(prompt) ?
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return s
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}
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// read_line does the same as `read_line_utf8` but returns user input as a `string`.
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// (As opposed to `ustring` as returned by `read_line_utf8`).
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// NOTE that this version of `read_line` is a standalone function without
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// persistent functionalities (e.g. history).
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pub fn read_line(prompt string) ?string {
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mut r := Readline{}
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s := r.read_line(prompt) ?
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return s
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}
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