| // Copyright 2020 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| use { |
| rustyline::{ |
| completion::Completer, error::ReadlineError, highlight::Highlighter, hint::Hinter, Helper, |
| }, |
| std::{ |
| borrow::Cow::{self, Borrowed, Owned}, |
| fmt, |
| str::FromStr, |
| }, |
| }; |
| |
| //TODO(fxbug.dev/46991): Make the macro a library |
| /// Macro to generate a command enum and its impl. |
| macro_rules! gen_commands { |
| ($name:ident { |
| $($variant:ident = ($val:expr, [$($arg:expr),*], $help:expr)),*, |
| }) => { |
| /// Enum of all possible commands |
| #[derive(PartialEq)] |
| pub enum $name { |
| $($variant),* |
| } |
| |
| impl $name { |
| /// Returns a list of the string representations of all variants |
| pub fn variants() -> Vec<String> { |
| let mut variants = Vec::new(); |
| $(variants.push($val.to_string());)* |
| variants |
| } |
| |
| pub fn arguments(&self) -> &'static str { |
| match self { |
| $( |
| $name::$variant => concat!($("<", $arg, "> ",)*) |
| ),* |
| } |
| } |
| |
| /// Help string for a given variant. The format is "command <arg>.. -- help message" |
| #[allow(unused)] |
| pub fn cmd_help(&self) -> &'static str { |
| match self { |
| $( |
| $name::$variant => concat!($val, " ", $("<", $arg, "> ",)* "-- ", $help) |
| ),* |
| } |
| } |
| |
| /// Multiline help string for `$name` including usage of all variants. |
| pub fn help_msg() -> &'static str { |
| concat!("Commands:\n", $( |
| "\t", $val, " ", $("<", $arg, "> ",)* "-- ", $help, "\n" |
| ),*) |
| } |
| |
| } |
| |
| impl fmt::Display for $name { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| match *self { |
| $($name::$variant => write!(f, $val)),* , |
| } |
| } |
| } |
| |
| impl FromStr for $name { |
| type Err = (); |
| |
| fn from_str(s: &str) -> Result<$name, ()> { |
| match s { |
| $($val => Ok($name::$variant)),* , |
| _ => Err(()), |
| } |
| } |
| } |
| |
| } |
| } |
| |
| gen_commands! { |
| Command { |
| Get = ("get", [], |
| "Get all information of the battery state"), |
| Set = ("set", ["<attribute1 value1> ... [attributeN valueN]", "--help"], |
| "Set state of battery in one line | Print help message"), |
| Reconnect = ("reconnect", [], |
| "Connect the real battery and disconnect the simulator"), |
| Disconnect = ("disconnect", [], |
| "Disconnect the real battery and connect to the simulator"), |
| Help = ("help", [], "Help message"), |
| Exit = ("exit", [], "Exit/Close REPL"), |
| Quit = ("quit", [], "Quit/Close REPL"), |
| |
| } |
| } |
| |
| /// CmdHelper provides completion, hints, and highlighting for battery-simulator |
| pub struct CmdHelper; |
| |
| impl CmdHelper { |
| pub fn new() -> CmdHelper { |
| CmdHelper {} |
| } |
| } |
| |
| impl Completer for CmdHelper { |
| type Candidate = String; |
| |
| fn complete(&self, line: &str, _pos: usize) -> Result<(usize, Vec<String>), ReadlineError> { |
| let mut variants = Vec::new(); |
| for variant in Command::variants() { |
| if variant.starts_with(line) { |
| variants.push(variant) |
| } |
| } |
| Ok((0, variants)) |
| } |
| } |
| |
| impl Hinter for CmdHelper { |
| /// CmdHelper provides hints for commands with arguments |
| fn hint(&self, line: &str, _pos: usize) -> Option<String> { |
| let needs_space = !line.ends_with(" "); |
| line.trim() |
| .parse::<Command>() |
| .map(|cmd| { |
| format!("{}{}", if needs_space { " " } else { "" }, cmd.arguments().to_string(),) |
| }) |
| .ok() |
| } |
| } |
| |
| impl Highlighter for CmdHelper { |
| /// CmdHelper provides highlights for commands with hints |
| fn highlight_hint<'h>(&self, hint: &'h str) -> Cow<'h, str> { |
| if hint.trim().is_empty() { |
| Borrowed(hint) |
| } else { |
| Owned(format!("\x1b[90m{}\x1b[0m", hint)) |
| } |
| } |
| } |
| |
| /// CmdHelper can be used as an `Editor` helper for entering input commands |
| impl Helper for CmdHelper {} |
| |
| /// Represents either continuation or breaking out of a read-evaluate-print loop. |
| pub enum ReplControl { |
| Break, |
| Continue, |
| } |