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-rw-r--r--src/main.rs32
1 files changed, 29 insertions, 3 deletions
diff --git a/src/main.rs b/src/main.rs
index e60a893..0abcea8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,4 @@
+extern crate bytecount;
extern crate lalrpop_util;
#[macro_use]
extern crate nom;
@@ -11,16 +12,41 @@ pub mod parser;
use std::io::{self, Read};
+fn print_error(message: &str, source: &str, start: usize, end: usize) {
+ let line_number = bytecount::count(source[..start].as_bytes(), '\n' as u8);
+ let line_start = source[..start].rfind('\n').map(|i| i + 1).unwrap_or(0);
+ let line_end = source[end..].find('\n').unwrap_or(0) + end;
+ let context = &source[line_start..line_end];
+
+ println!("error: {}", message);
+ println!(" --> (stdin):{}:0", line_number);
+ let line_number_str = line_number.to_string();
+ let line_number_width = line_number_str.len();
+ println!("{:w$} |", "", w = line_number_width);
+ println!("{} | {}", line_number_str, context);
+ println!("{:w$} | {:so$}{:^>ew$}", "", "", "",
+ w = line_number_width,
+ so = source[line_start..start].chars().count(),
+ ew = ::std::cmp::max(1, source[start..end].chars().count()));
+}
+
fn main() {
let mut buffer = String::new();
io::stdin().read_to_string(&mut buffer).unwrap();
match parser::parse_expr(&buffer) {
Ok(e) => println!("{:?}", e),
Err(lalrpop_util::ParseError::User { error: lexer::LexicalError::Error(pos, e) }) => {
- let context = &buffer[pos..::std::cmp::min(buffer.len(), pos + 20)];
- println!("Unexpected token in {:?}: {:?}...", e, context);
+ print_error(&format!("Unexpected token {:?}", e), &buffer, pos, pos);
+ }
+ Err(lalrpop_util::ParseError::UnrecognizedToken { token: Some((start, t, end)), expected: e }) => {
+ print_error(&format!("Unrecognized token {:?}", t), &buffer, start, end);
+ if e.len() > 0 {
+ println!("Expected {:?}", e);
+ }
+ }
+ Err(e) => {
+ print_error(&format!("Parser error {:?}", e), &buffer, 0, 0);
}
- Err(e) => println!("{:?}", e),
}
/*