schala/schala-repl/src/repl.rs
2018-09-21 19:43:50 -07:00

366 lines
13 KiB
Rust

use std::fmt::Write as FmtWrite;
use std::io::{Read, Write};
use std::fs::File;
use colored::*;
use itertools::Itertools;
use language::{ProgrammingLanguageInterface, EvalOptions,
PassDebugOptionsDescriptor};
pub struct Repl {
options: EvalOptions,
languages: Vec<Box<ProgrammingLanguageInterface>>,
current_language_index: usize,
interpreter_directive_sigil: char,
line_reader: ::linefeed::interface::Interface<::linefeed::terminal::DefaultTerminal>,
}
impl Repl {
pub fn new(languages: Vec<Box<ProgrammingLanguageInterface>>, initial_index: usize) -> Repl {
use linefeed::Interface;
let i = if initial_index < languages.len() { initial_index } else { 0 };
let line_reader = Interface::new("schala-repl").unwrap();
Repl {
options: Repl::get_options(),
languages: languages,
current_language_index: i,
interpreter_directive_sigil: ':',
line_reader
}
}
fn get_cur_language(&self) -> &ProgrammingLanguageInterface {
self.languages[self.current_language_index].as_ref()
}
fn get_options() -> EvalOptions {
File::open(".schala_repl")
.and_then(|mut file| {
let mut contents = String::new();
file.read_to_string(&mut contents)?;
Ok(contents)
})
.and_then(|contents| {
let options: EvalOptions = ::serde_json::from_str(&contents)?;
Ok(options)
}).unwrap_or(EvalOptions::default())
}
fn save_options(&self) {
let ref options = self.options;
let read = File::create(".schala_repl")
.and_then(|mut file| {
let buf = ::serde_json::to_string(options).unwrap();
file.write_all(buf.as_bytes())
});
if let Err(err) = read {
println!("Error saving .schala_repl file {}", err);
}
}
pub fn run(&mut self) {
use linefeed::ReadResult;
println!("Schala MetaInterpreter version {}", ::VERSION_STRING);
println!("Type {}help for help with the REPL", self.interpreter_directive_sigil);
self.line_reader.load_history(".schala_history").unwrap_or(());
loop {
let language_name = self.get_cur_language().get_language_name();
let directives = self.get_directives();
let tab_complete_handler = TabCompleteHandler::new(self.interpreter_directive_sigil, directives);
self.line_reader.set_completer(::std::sync::Arc::new(tab_complete_handler));
let prompt_str = format!("{} >> ", language_name);
self.line_reader.set_prompt(&prompt_str).unwrap();
match self.line_reader.read_line() {
Err(e) => {
println!("Terminal read error: {}", e);
},
Ok(ReadResult::Eof) => break,
Ok(ReadResult::Signal(_)) => break,
Ok(ReadResult::Input(ref input)) => {
self.line_reader.add_history_unique(input.to_string());
let output = match input.chars().nth(0) {
Some(ch) if ch == self.interpreter_directive_sigil => self.handle_interpreter_directive(input),
_ => Some(self.input_handler(input)),
};
if let Some(o) = output {
println!("=> {}", o);
}
}
}
}
self.line_reader.save_history(".schala_history").unwrap_or(());
self.save_options();
println!("Exiting...");
}
fn input_handler(&mut self, input: &str) -> String {
let ref mut language = self.languages[self.current_language_index];
let interpreter_output = language.execute_pipeline(input, &self.options);
interpreter_output.to_repl()
}
fn get_directives(&self) -> CommandTree {
let ref passes = self.get_cur_language().get_passes();
let passes_directives: Vec<CommandTree> = passes.iter()
.map(|pass_descriptor| {
let name = &pass_descriptor.name;
if pass_descriptor.debug_options.len() == 0 {
CommandTree::term(name, None)
} else {
let sub_opts: Vec<CommandTree> = pass_descriptor.debug_options.iter()
.map(|o| CommandTree::term(o, None)).collect();
CommandTree::NonTerminal(
name.clone(),
sub_opts,
None
)
}
}).collect();
CommandTree::Top(vec![
CommandTree::term("exit", Some("exit the REPL")),
CommandTree::term("quit", Some("exit the REPL")),
CommandTree::term("help", Some("Print this help message")),
CommandTree::NonTerminal(format!("debug"), vec![
CommandTree::term("passes", None),
CommandTree::NonTerminal(format!("show"), passes_directives.clone(), None),
CommandTree::NonTerminal(format!("hide"), passes_directives.clone(), None),
], Some(format!("show or hide pass info for a given pass, or display the names of all passes"))),
CommandTree::NonTerminal(format!("lang"), vec![
CommandTree::term("next", None),
CommandTree::term("prev", None),
CommandTree::NonTerminal(format!("go"), vec![], None)//TODO
], Some(format!("switch between languages, or go directly to a langauge by name"))),
CommandTree::term("doc", Some("Get language-specific help for an item")),
])
}
fn handle_interpreter_directive(&mut self, input: &str) -> Option<String> {
let mut iter = input.chars();
iter.next();
let commands: Vec<&str> = iter
.as_str()
.split_whitespace()
.collect();
let cmd: &str = match commands.get(0).clone() {
None => return None,
Some(s) => s
};
match cmd {
"exit" | "quit" => {
self.save_options();
::std::process::exit(0)
},
"lang" | "language" => match commands.get(1) {
Some(&"show") => {
let mut buf = String::new();
for (i, lang) in self.languages.iter().enumerate() {
write!(buf, "{}{}\n", if i == self.current_language_index { "* "} else { "" }, lang.get_language_name()).unwrap();
}
Some(buf)
},
Some(&"go") => match commands.get(2) {
None => Some(format!("Must specify a language name")),
Some(&desired_name) => {
for (i, _) in self.languages.iter().enumerate() {
let lang_name = self.languages[i].get_language_name();
if lang_name.to_lowercase() == desired_name.to_lowercase() {
self.current_language_index = i;
return Some(format!("Switching to {}", self.languages[self.current_language_index].get_language_name()));
}
}
Some(format!("Language {} not found", desired_name))
}
},
Some(&"next") | Some(&"n") => {
self.current_language_index = (self.current_language_index + 1) % self.languages.len();
Some(format!("Switching to {}", self.languages[self.current_language_index].get_language_name()))
},
Some(&"previous") | Some(&"p") | Some(&"prev") => {
self.current_language_index = if self.current_language_index == 0 { self.languages.len() - 1 } else { self.current_language_index - 1 };
Some(format!("Switching to {}", self.languages[self.current_language_index].get_language_name()))
},
Some(e) => Some(format!("Bad `lang(uage)` argument: {}", e)),
None => Some(format!("Valid arguments for `lang(uage)` are `show`, `next`|`n`, `previous`|`prev`|`n`"))
},
"help" => {
let mut buf = String::new();
let ref lang = self.languages[self.current_language_index];
let directives = match self.get_directives() {
CommandTree::Top(children) => children,
_ => panic!("Top-level CommandTree not Top")
};
writeln!(buf, "MetaInterpreter options").unwrap();
writeln!(buf, "-----------------------").unwrap();
for directive in directives {
let trailer = " ";
writeln!(buf, "{}{}- {}", directive.get_cmd(), trailer, directive.get_help()).unwrap();
}
writeln!(buf, "").unwrap();
writeln!(buf, "Language-specific help for {}", lang.get_language_name()).unwrap();
writeln!(buf, "-----------------------").unwrap();
writeln!(buf, "{}", lang.custom_interpreter_directives_help()).unwrap();
Some(buf)
},
"debug" => self.handle_debug(commands),
"doc" => self.languages[self.current_language_index]
.get_doc(&commands)
.or(Some(format!("No docs implemented"))),
e => self.languages[self.current_language_index]
.handle_custom_interpreter_directives(&commands)
.or(Some(format!("Unknown command: {}", e)))
}
}
fn handle_debug(&mut self, commands: Vec<&str>) -> Option<String> {
let passes = self.get_cur_language().get_passes();
match commands.get(1) {
Some(&"passes") => Some(
passes.into_iter()
.map(|desc| {
if self.options.debug_passes.contains_key(&desc.name) {
let color = "green";
format!("*{}", desc.name.color(color))
} else {
desc.name
}
})
.intersperse(format!(" -> "))
.collect()),
b @ Some(&"show") | b @ Some(&"hide") => {
let show = b == Some(&"show");
let debug_pass: String = match commands.get(2) {
Some(s) => s.to_string(),
None => return Some(format!("Must specify a stage to debug")),
};
let pass_opt = commands.get(3);
if let Some(desc) = passes.iter().find(|desc| desc.name == debug_pass) {
let mut opts = vec![];
if let Some(opt) = pass_opt {
opts.push(opt.to_string());
}
let msg = format!("{} debug for pass {}", if show { "Enabling" } else { "Disabling" }, debug_pass);
if show {
self.options.debug_passes.insert(desc.name.clone(), PassDebugOptionsDescriptor { opts });
} else {
self.options.debug_passes.remove(&desc.name);
}
Some(msg)
} else {
Some(format!("Couldn't find stage: {}", debug_pass))
}
},
_ => Some(format!("Unknown debug command"))
}
}
}
struct TabCompleteHandler {
sigil: char,
top_level_commands: CommandTree,
}
use linefeed::complete::{Completion, Completer};
use linefeed::terminal::Terminal;
impl TabCompleteHandler {
fn new(sigil: char, top_level_commands: CommandTree) -> TabCompleteHandler {
TabCompleteHandler {
top_level_commands,
sigil,
}
}
}
impl<T: Terminal> Completer<T> for TabCompleteHandler {
fn complete(&self, word: &str, prompter: &::linefeed::prompter::Prompter<T>, start: usize, _end: usize) -> Option<Vec<Completion>> {
let line = prompter.buffer();
if line.starts_with(&format!("{}", self.sigil)) {
let mut words = line[1..(if start == 0 { 1 } else { start })].split_whitespace();
let mut completions = Vec::new();
let mut command_tree: Option<&CommandTree> = Some(&self.top_level_commands);
loop {
match words.next() {
None => {
let top = match command_tree {
Some(CommandTree::Top(_)) => true,
_ => false
};
let word = if top { word.get(1..).unwrap() } else { word };
for cmd in command_tree.map(|x| x.get_children()).unwrap_or(vec![]).into_iter() {
if cmd.starts_with(word) {
completions.push(Completion {
completion: format!("{}{}", if top { ":" } else { "" }, cmd),
display: Some(cmd.clone()),
suffix: ::linefeed::complete::Suffix::Some(' ')
})
}
}
break;
},
Some(s) => {
let new_ptr: Option<&CommandTree> = command_tree.and_then(|cm| match cm {
CommandTree::Top(children) => children.iter().find(|c| c.get_cmd() == s),
CommandTree::NonTerminal(_, children, _) => children.iter().find(|c| c.get_cmd() == s),
CommandTree::Terminal(_, _) => None,
});
command_tree = new_ptr;
}
}
}
Some(completions)
} else {
None
}
}
}
#[derive(Clone)]
enum CommandTree {
Terminal(String, Option<String>),
NonTerminal(String, Vec<CommandTree>, Option<String>),
Top(Vec<CommandTree>),
}
impl CommandTree {
fn term(s: &str, help: Option<&str>) -> CommandTree {
CommandTree::Terminal(s.to_string(), help.map(|x| x.to_string()))
}
fn get_cmd(&self) -> String {
match self {
CommandTree::Terminal(s, _) => s.to_string(),
CommandTree::NonTerminal(s, _, _) => s.to_string(),
CommandTree::Top(_) => "".to_string(),
}
}
fn get_help(&self) -> String {
match self {
CommandTree::Terminal(_, h) => h.as_ref().map(|h| h.clone()).unwrap_or(format!("")),
CommandTree::NonTerminal(_, _, h) => h.as_ref().map(|h| h.clone()).unwrap_or(format!("")),
CommandTree::Top(_) => "".to_string(),
}
}
fn get_children(&self) -> Vec<String> {
match self {
CommandTree::Terminal(_, _) => vec![],
CommandTree::NonTerminal(_, children, _) => children.iter().map(|x| x.get_cmd()).collect(),
CommandTree::Top(children) => children.iter().map(|x| x.get_cmd()).collect(),
}
}
}