Fix line/column position for strings containing \r\n

Fixes #153

peg-tests/src/test_grammar.rustpeg

@@ -101,3 +101,5 @@ pub infix_arith -> i64 = #infix<number> {
 issue152 -> i32 // a
     = "5" { 5 //b
 }
+
+pub error_pos = ("a" / "\n" / "\r")*

peg-tests/src/tests.rs

@@ -144,3 +144,24 @@ fn test_infix_arith() {
 	assert_eq!(infix_arith("2+2^2^2^2/2+2"), Ok(32772));
 	assert_eq!(infix_arith("1024/2/2/2+1"), Ok(129));
 }
+
+#[test]
+fn test_error_pos() {
+    let err = error_pos("aab\n").unwrap_err();
+    assert_eq!(err.line, 1);
+    assert_eq!(err.column, 3);
+    assert_eq!(err.offset, 2);
+    assert_eq!(err.expected, ["\r", "\n", "a"].iter().map(|x| *x).collect());
+
+    let err = error_pos("aa\naaaa\nbaaa\n").unwrap_err();
+    assert_eq!(err.line, 3);
+    assert_eq!(err.column, 1);
+
+    let err = error_pos("aa\naaaa\naaab\naa").unwrap_err();
+    assert_eq!(err.line, 3);
+    assert_eq!(err.column, 4);
+
+    let err = error_pos("aa\r\naaaa\r\naaab\r\naa").unwrap_err();
+    assert_eq!(err.line, 3);
+    assert_eq!(err.column, 4);
+}

src/grammar.rs

@@ -48,12 +48,10 @@ input : & str , state : & mut ParseState , pos : usize ) -> RuleResult < (  )
 let ( _ , next ) = char_range_at ( input , pos ) ; Matched ( next , (  ) ) }
 else { state . mark_failure ( pos , "<character>" ) } } fn pos_to_line (
 input : & str , pos : usize ) -> ( usize , usize ) {
-let mut remaining = pos ; let mut lineno : usize = 1 ; for line in input .
-lines (  ) {
-let line_length = line . len (  ) + 1 ; if remaining < line_length {
-return ( lineno , remaining + 1 ) ; } remaining -= line_length ; lineno += 1 ;
-} return ( lineno , remaining + 1 ) ; } impl < 'input > ParseState < 'input >
-{
+let before = & input [ .. pos ] ; let line = before . as_bytes (  ) . iter (
+) . filter ( | && c | c == b'\n' ) . count (  ) + 1 ; let col = before . chars
+(  ) . rev (  ) . take_while ( | & c | c != '\n' ) . count (  ) + 1 ; (
+line , col ) } impl < 'input > ParseState < 'input > {
 fn mark_failure ( & mut self , pos : usize , expected : & 'static str ) ->
 RuleResult < (  ) > {
 if self . suppress_fail == 0 {

src/translate.rs

@@ -221,17 +221,10 @@ static HELPERS: &'static str = stringify! {
 	}
 
 	fn pos_to_line(input: &str, pos: usize) -> (usize, usize) {
-		let mut remaining = pos;
-		let mut lineno: usize = 1;
-		for line in input.lines() {
-			let line_length = line.len() + 1;
-			if remaining < line_length {
-				return (lineno, remaining + 1);
-			}
-			remaining -= line_length;
-			lineno += 1;
-		}
-		return (lineno, remaining + 1);
+		let before = &input[..pos];
+		let line = before.as_bytes().iter().filter(|&&c| c == b'\n').count() + 1;
+		let col = before.chars().rev().take_while(|&c| c != '\n').count() + 1;
+		(line, col)
 	}
 
 	impl<'input> ParseState<'input> {