keep a line number so errors are easier to find

1 files changed, 8 insertions, 8 deletions

diff --git a/src/makefile/mod.rs b/src/makefile/mod.rs
index bd8838a..4c39160 100644
--- a/src/makefile/mod.rs
+++ b/src/makefile/mod.rs
@@ -270,9 +270,9 @@ impl Makefile {
     }
 
     pub fn and_read(&mut self, source: impl BufRead) -> &mut Makefile {
-        let mut lines_iter = source.lines().peekable();
+        let mut lines_iter = source.lines().enumerate().peekable();
         while lines_iter.peek().is_some() {
-            let line = match lines_iter.next() {
+            let (line_number, line) = match lines_iter.next() {
                 Some(x) => x,
                 // fancy Rust trick: break-with-an-argument to return a value from a
                 // `loop` expression
@@ -284,7 +284,7 @@ impl Makefile {
             // handle escaped newlines
             while line.ends_with(r"\") {
                 let next_line = match lines_iter.next() {
-                    Some(x) => x,
+                    Some((_, x)) => x,
                     None => Ok("".into()),
                 };
                 let next_line = next_line.expect("failed to read line of makefile!");
@@ -362,7 +362,7 @@ impl Makefile {
                             Some((prerequisites, mut command)) => {
                                 while command.ends_with(r"\") && lines_iter.peek().is_some() {
                                     command.strip_suffix(r"\");
-                                    command.extend(tokenize(&lines_iter.next().unwrap().unwrap()));
+                                    command.extend(tokenize(&lines_iter.next().unwrap().1.unwrap()));
                                 }
                                 (prerequisites, vec![command])
                             }
@@ -371,12 +371,12 @@ impl Makefile {
                         let prerequisites = self.expand_macros(&prerequisites, None);
                         let prerequisites = prerequisites.split_whitespace().map(|x| x.into()).collect::<Vec<String>>();
 
-                        while lines_iter.peek().and_then(|x| x.as_ref().ok()).map_or(false, |line| line.starts_with('\t')) {
-                            let line = lines_iter.next().unwrap().unwrap();
+                        while lines_iter.peek().and_then(|(_, x)| x.as_ref().ok()).map_or(false, |line| line.starts_with('\t')) {
+                            let line = lines_iter.next().unwrap().1.unwrap();
                             let mut line: String = line.strip_prefix("\t").unwrap().into();
                             while line.ends_with('\\') {
                                 match lines_iter.next() {
-                                    Some(Ok(next_line)) => {
+                                    Some((_, Ok(next_line))) => {
                                         let next_line = next_line.strip_prefix("\t").unwrap_or(&next_line);
                                         line.push('\n');
                                         line.push_str(next_line);
@@ -497,7 +497,7 @@ impl Makefile {
                         self.macros.insert(name.into(), (MacroSource::File, value));
                     }
                     LineType::Unknown => {
-                        panic!("Unknown line {:?}", line_tokens);
+                        panic!("error: line {}: unknown line {:?}", line_number, line_tokens);
                     }
                 }
             }