Improve repl and rhai_runner examples with error messages.

This commit is contained in:
Stephen Chung
2020-03-10 11:25:34 +08:00
parent 2d80ee2f18
commit 711cd9bb1c
3 changed files with 154 additions and 51 deletions

View File

@@ -1,25 +1,66 @@
use rhai::{Engine, RegisterFn, Scope};
use std::io::{stdin, stdout, Write};
use std::process::exit;
use rhai::{Engine, EvalAltResult, Scope};
use std::{
io::{stdin, stdout, Write},
iter,
};
pub fn main() {
let mut engine = Engine::new();
let mut scope = Scope::new();
fn print_error(input: &str, err: EvalAltResult) {
fn padding(pad: &str, len: usize) -> String {
iter::repeat(pad).take(len).collect::<String>()
}
engine.register_fn("exit", || exit(0));
let lines: Vec<_> = input.split("\n").collect();
loop {
print!("> ");
let mut input = String::new();
stdout().flush().expect("couldn't flush stdout");
if let Err(e) = stdin().read_line(&mut input) {
println!("input error: {}", e);
// Print error
match err.position() {
p if p.is_eof() => {
// EOF
let last = lines[lines.len() - 2];
println!("{}", last);
println!("{}^ {}", padding(" ", last.len() - 1), err);
}
p if p.is_none() => {
// No position
println!("{}", err);
}
p => {
// Specific position
let pos_text = format!(
" (line {}, position {})",
p.line().unwrap(),
p.position().unwrap()
);
if let Err(e) = engine.consume_with_scope(&mut scope, &input) {
println!("error: {}", e);
println!("{}", lines[p.line().unwrap() - 1]);
println!(
"{}^ {}",
padding(" ", p.position().unwrap() - 1),
err.to_string().replace(&pos_text, "")
);
}
}
}
fn main() {
let mut engine = Engine::new();
let mut scope = Scope::new();
let mut input = String::new();
loop {
print!("rhai> ");
stdout().flush().expect("couldn't flush stdout");
input.clear();
if let Err(err) = stdin().read_line(&mut input) {
println!("input error: {}", err);
}
if let Err(err) = engine.consume_with_scope(&mut scope, true, &input) {
println!("");
print_error(&input, err);
println!("");
}
}
}

View File

@@ -1,27 +1,79 @@
use rhai::{Engine, RegisterFn};
use std::env;
use std::fmt::Display;
use rhai::{Engine, EvalAltResult};
use std::{env, fs::File, io::Read, iter, process::exit};
fn showit<T: Display>(x: &mut T) -> () {
println!("{}", x)
fn padding(pad: &str, len: usize) -> String {
iter::repeat(pad).take(len).collect::<String>()
}
fn main() {
for fname in env::args().skip(1) {
let mut engine = Engine::new();
fn eprint_error(input: &str, err: EvalAltResult) {
fn eprint_line(lines: &Vec<&str>, line: usize, pos: usize, err: &str) {
let line_no = format!("{}: ", line);
let pos_text = format!(" (line {}, position {})", line, pos);
engine.register_fn("print", showit as fn(x: &mut i32) -> ());
engine.register_fn("print", showit as fn(x: &mut i64) -> ());
engine.register_fn("print", showit as fn(x: &mut u32) -> ());
engine.register_fn("print", showit as fn(x: &mut u64) -> ());
engine.register_fn("print", showit as fn(x: &mut f32) -> ());
engine.register_fn("print", showit as fn(x: &mut f64) -> ());
engine.register_fn("print", showit as fn(x: &mut bool) -> ());
engine.register_fn("print", showit as fn(x: &mut String) -> ());
eprintln!("{}{}", line_no, lines[line - 1]);
eprintln!(
"{}^ {}",
padding(" ", line_no.len() + pos - 1),
err.replace(&pos_text, "")
);
eprintln!("");
}
match engine.eval_file::<()>(&fname) {
Ok(_) => (),
Err(e) => println!("Error: {}", e),
let lines: Vec<_> = input.split("\n").collect();
// Print error
match err.position() {
p if p.is_eof() => {
// EOF
let line = lines.len() - 1;
let pos = lines[line - 1].len();
eprint_line(&lines, line, pos, &err.to_string());
}
p if p.is_none() => {
// No position
eprintln!("{}", err);
}
p => {
// Specific position
eprint_line(
&lines,
p.line().unwrap(),
p.position().unwrap(),
&err.to_string(),
)
}
}
}
fn main() {
for filename in env::args().skip(1) {
let mut engine = Engine::new();
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();
match f.read_to_string(&mut contents) {
Err(err) => {
eprintln!("Error reading script file: {}\n{}", filename, err);
exit(1);
}
_ => (),
}
if let Err(err) = engine.consume(&contents) {
eprintln!("{}", padding("=", filename.len()));
eprintln!("{}", filename);
eprintln!("{}", padding("=", filename.len()));
eprintln!("");
eprint_error(&contents, err);
}
}
}