Initial project import

tools/v/vlib/readline/readline_default.c.v

@@ -0,0 +1,86 @@
+// Copyright (c) 2019-2024 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+//
+// TODO: Mac version needs to be implemented
+// Will serve as more advanced input method
+// based on the work of https://github.com/AmokHuginnsson/replxx
+//
+module readline
+
+import os
+
+// termios definitions
+// https://github.com/openbsd/src/blob/master/sys/sys/termios.h
+// https://github.com/vocho/openqnx/blob/master/trunk/lib/c/public/termios.h
+// https://github.com/omniti-labs/illumos-omnios/blob/master/usr/src/uts/common/sys/termios.h
+// https://github.com/torvalds/linux/blob/master/include/uapi/asm-generic/termbits.h
+
+struct Termios {
+}
+
+// Only use standard os.get_line
+// Need implementation for readline capabilities
+//
+// 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.
+pub fn (mut r Readline) read_line_utf8(prompt string) ![]rune {
+	r.current = []rune{}
+	r.cursor = 0
+	r.prompt = prompt
+	r.search_index = 0
+	if r.previous_lines.len <= 1 {
+		r.previous_lines << []rune{}
+		r.previous_lines << []rune{}
+	} else {
+		r.previous_lines[0] = []rune{}
+	}
+	print(r.prompt)
+	line := os.get_raw_line()
+	if line.len >= 0 {
+		r.current = line.runes()
+	}
+	r.previous_lines[0] = []rune{}
+	r.search_index = 0
+	if r.current.len == 0 {
+		return error('empty line')
+	}
+	return r.current
+}
+
+// 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`).
+pub fn (mut r Readline) read_line(prompt string) !string {
+	s := r.read_line_utf8(prompt)!
+	return s.string()
+}
+
+// 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).
+pub fn read_line_utf8(prompt string) ![]rune {
+	mut r := Readline{}
+	s := r.read_line_utf8(prompt)!
+	return s
+}
+
+// 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).
+pub fn read_line(prompt string) !string {
+	mut r := Readline{}
+	s := r.read_line(prompt)!
+	return s
+}