rhai/examples/rhai_runner.rs
2020-03-25 11:51:13 +08:00

88 lines
2.5 KiB
Rust

use rhai::{Engine, EvalAltResult, Position};
#[cfg(not(feature = "no_optimize"))]
use rhai::OptimizationLevel;
use std::{env, fs::File, io::Read, iter, process::exit};
fn padding(pad: &str, len: usize) -> String {
iter::repeat(pad).take(len).collect::<String>()
}
fn eprint_error(input: &str, err: EvalAltResult) {
fn eprint_line(lines: &[&str], line: usize, pos: usize, err: &str) {
let line_no = format!("{}: ", line);
let pos_text = format!(" (line {}, position {})", line, pos);
eprintln!("{}{}", line_no, lines[line - 1]);
eprintln!(
"{}^ {}",
padding(" ", line_no.len() + pos - 1),
err.replace(&pos_text, "")
);
eprintln!("");
}
let lines: Vec<_> = input.split('\n').collect();
// Print error
let pos = if err.position().is_eof() {
let last = lines[lines.len() - 1];
Position::new(lines.len(), last.len() + 1)
} else {
err.position()
};
match pos {
p if p.is_eof() => panic!("should not be EOF"),
p if p.is_none() => {
// No position
eprintln!("{}", err);
}
p => {
// Specific position
let err_text = match err {
EvalAltResult::ErrorRuntime(err, _) if !err.is_empty() => {
format!("Runtime error: {}", err)
}
err => err.to_string(),
};
eprint_line(&lines, p.line().unwrap(), p.position().unwrap(), &err_text)
}
}
}
fn main() {
for filename in env::args().skip(1) {
let mut engine = Engine::new();
#[cfg(not(feature = "no_optimize"))]
engine.set_optimization_level(OptimizationLevel::Full);
let mut f = match File::open(&filename) {
Err(err) => {
eprintln!("Error reading script file: {}\n{}", filename, err);
exit(1);
}
Ok(f) => f,
};
let mut contents = String::new();
if let Err(err) = f.read_to_string(&mut contents) {
eprintln!("Error reading script file: {}\n{}", filename, err);
exit(1);
}
if let Err(err) = engine.consume(false, &contents) {
eprintln!("{}", padding("=", filename.len()));
eprintln!("{}", filename);
eprintln!("{}", padding("=", filename.len()));
eprintln!("");
eprint_error(&contents, err);
}
}
}