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use std::fmt::Write as _;
use std::io::{self, Write};
use std::path::{Path, PathBuf};
use atty::Stream;
use termcolor::{Color, ColorChoice, ColorSpec, StandardStream, WriteColor};
pub struct Error {
source: anyhow::Error,
location: Option<ErrorLocation>,
}
impl Error {
pub(crate) fn new(source: anyhow::Error, location: Option<ErrorLocation>) -> Self {
Error { source, location }
}
pub fn print_stderr(&self) -> io::Result<()> {
let color_choice = if atty::is(Stream::Stderr) {
ColorChoice::Auto
} else {
ColorChoice::Never
};
let mut stderr = StandardStream::stderr(color_choice);
println!("^^^ +++");
match &self.location {
Some(location) => {
let mut color_spec = ColorSpec::new();
color_spec.set_bold(true);
stderr.set_color(&color_spec)?;
write!(
&mut stderr,
"{}:{}:{}: ",
location.filename.display(),
location.line,
location.col
)?;
write_error_heading(&mut stderr, &color_spec)?;
writeln!(&mut stderr, "{:#}", self.source)?;
color_spec.set_bold(false);
stderr.set_color(&color_spec)?;
write!(&mut stderr, "{}", location.snippet)?;
writeln!(&mut stderr, "{}^", " ".repeat(location.col - 1))
}
None => {
let color_spec = ColorSpec::new();
write_error_heading(&mut stderr, &color_spec)?;
writeln!(&mut stderr, "{:#}", self.source)?;
Ok(())
}
}
}
}
fn write_error_heading(stream: &mut StandardStream, color_spec: &ColorSpec) -> io::Result<()> {
stream.set_color(color_spec.clone().set_fg(Some(Color::Red)))?;
write!(stream, "error: ")?;
stream.set_color(color_spec)
}
impl From<anyhow::Error> for Error {
fn from(source: anyhow::Error) -> Error {
Error {
source,
location: None,
}
}
}
pub(crate) struct ErrorLocation {
filename: PathBuf,
snippet: String,
line: usize,
col: usize,
}
impl ErrorLocation {
pub(crate) fn new(filename: &Path, contents: &str, line: usize, col: usize) -> ErrorLocation {
let mut snippet = String::new();
writeln!(&mut snippet, " |").unwrap();
for (i, l) in contents.lines().enumerate() {
if i >= line {
break;
} else if i + 2 >= line {
writeln!(&mut snippet, "{:4} | {}", i + 1, l).unwrap();
}
}
write!(&mut snippet, " | ").unwrap();
ErrorLocation {
filename: filename.to_path_buf(),
snippet,
line,
col,
}
}
}
pub(crate) struct PosError {
pub(crate) source: anyhow::Error,
pub(crate) pos: Option<usize>,
}
impl PosError {
pub(crate) fn new(source: anyhow::Error, pos: usize) -> PosError {
PosError {
source,
pos: Some(pos),
}
}
}
impl From<anyhow::Error> for PosError {
fn from(source: anyhow::Error) -> PosError {
PosError { source, pos: None }
}
}