0d0b43ed88
rustfmt only sometimes detects path-based nested config files (probably some kind of race?), so my users folder uses a separate formatting check for rustfmt to avoid flaky CI. Enough flakes around already ... Change-Id: Ifd862f9974f071b3a256643dd8e56c019116156a Reviewed-on: https://cl.tvl.fyi/c/depot/+/5242 Reviewed-by: tazjin <tazjin@tvl.su> Autosubmit: tazjin <tazjin@tvl.su> Tested-by: BuildkiteCI
71 lines
1.7 KiB
Rust
71 lines
1.7 KiB
Rust
use std::io::Write;
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use std::{env, fs, io, process};
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mod bytecode;
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mod scanner;
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mod treewalk;
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/// Trait for making the different interpreters callable in the same
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/// way.
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pub trait Lox {
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type Value: std::fmt::Debug;
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type Error: std::fmt::Display;
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fn create() -> Self;
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fn interpret(&mut self, source: String) -> Result<Self::Value, Vec<Self::Error>>;
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}
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fn main() {
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let mut args = env::args();
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if args.len() > 2 {
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println!("Usage: rlox [script]");
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process::exit(1);
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}
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match env::var("LOX_INTERPRETER").as_ref().map(String::as_str) {
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Ok("treewalk") => pick::<treewalk::interpreter::Interpreter>(args.nth(1)),
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_ => pick::<bytecode::Interpreter>(args.nth(1)),
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}
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}
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fn pick<I: Lox>(file_arg: Option<String>) {
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if let Some(file) = file_arg {
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run_file::<I>(&file);
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} else {
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run_prompt::<I>();
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}
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}
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// Run Lox code from a file and print results to stdout
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fn run_file<I: Lox>(file: &str) {
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let contents = fs::read_to_string(file).expect("failed to read the input file");
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let mut lox = I::create();
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run(&mut lox, contents);
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}
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// Evaluate Lox code interactively in a shitty REPL.
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fn run_prompt<I: Lox>() {
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let mut line = String::new();
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let mut lox = I::create();
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loop {
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print!("> ");
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io::stdout().flush().unwrap();
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io::stdin()
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.read_line(&mut line)
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.expect("failed to read user input");
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run(&mut lox, std::mem::take(&mut line));
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line.clear();
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}
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}
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fn run<I: Lox>(lox: &mut I, code: String) {
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match lox.interpret(code) {
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Ok(result) => println!("=> {:?}", result),
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Err(errors) => {
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for error in errors {
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eprintln!("{}", error);
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}
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}
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}
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}
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