Add multi-line support to repl example.
@@ -13,15 +13,25 @@ fn print_error(input: &str, err: EvalAltResult) {
iter::repeat(pad).take(len).collect::<String>()
}
- let lines: Vec<_> = input.split("\n").collect();
+ let lines: Vec<_> = input.trim().split("\n").collect();
+
+ let line_no = if lines.len() > 1 {
+ match err.position() {
+ p if p.is_none() => "".to_string(),
+ p if p.is_eof() => format!("{}: ", lines.len()),
+ p => format!("{}: ", p.line().unwrap()),
+ }
+ } else {
+ "".to_string()
+ };
// 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);
+ let last = lines[lines.len() - 1];
+ println!("{}{}", line_no, last);
+ println!("{}^ {}", padding(" ", line_no.len() + last.len() - 1), err);
}
p if p.is_none() => {
// No position
@@ -35,7 +45,7 @@ fn print_error(input: &str, err: EvalAltResult) {
p.position().unwrap()
);
- println!("{}", lines[p.line().unwrap() - 1]);
+ println!("{}{}", line_no, lines[p.line().unwrap() - 1]);
let err_text = match err {
EvalAltResult::ErrorRuntime(err, _) if !err.is_empty() => {
@@ -46,13 +56,21 @@ fn print_error(input: &str, err: EvalAltResult) {
println!(
"{}^ {}",
- padding(" ", p.position().unwrap() - 1),
+ padding(" ", line_no.len() + p.position().unwrap() - 1),
err_text.replace(&pos_text, "")
);
}
}
}
+fn print_help() {
+ println!("help => print this help");
+ println!("quit, exit => quit");
+ println!("ast => print the last AST");
+ println!(r"end a line with '\' to continue to the next line.");
+ println!();
+}
+
fn main() {
let mut engine = Engine::new();
@@ -64,18 +82,44 @@ fn main() {
let mut input = String::new();
let mut ast: Option<AST> = None;
+ println!("Rhai REPL tool");
+ println!("==============");
+ print_help();
+
loop {
print!("rhai> ");
stdout().flush().expect("couldn't flush stdout");
input.clear();
+ loop {
if let Err(err) = stdin().read_line(&mut input) {
- println!("input error: {}", err);
+ panic!("input error: {}", err);
}
+ let line = input.as_str().trim_end();
+
+ // Allow line continuation
+ if line.ends_with('\\') {
+ let len = line.len();
+ input.truncate(len - 1);
+ input.push('\n');
+ } else {
+ break;
+ }
+
+ print!("> ");
+ stdout().flush().expect("couldn't flush stdout");
+ }
+
+ let script = input.trim();
+
// Implement standard commands
- match input.as_str().trim() {
+ match script {
+ "help" => {
+ print_help();
+ continue;
+ }
"exit" | "quit" => break, // quit
"ast" => {
if matches!(&ast, Some(_)) {
@@ -90,7 +134,7 @@ fn main() {
}
if let Err(err) = engine
- .compile_with_scope(&scope, &input)
+ .compile_with_scope(&scope, &script)
.map_err(EvalAltResult::ErrorParsing)
.and_then(|r| {
ast = Some(r);
