Aug 24, 2020 · Aug 24, 2020 · Aug 24, 2020 · Aug 24, 2020 · Aug 24, 2020 · Aug 24, 2020
diff --git a/src/formatter/mod.rs b/src/formatter/mod.rs
 use std::{
    cmp,
    fmt::{self, Display, Write},
    iter::once,
 };

 pub mod style;
                    } else {
                        false
                    };
                    // Specifies that it will end on the next character, so it will return
                    // until the next one to the final condition.
                    let mut ended = false;
                    let range = text
                        .char_indices()
                        .skip(left)
                        // Complete char iterator with final character
                        .chain(once((text.len(), '\0')))
                        // Take until the next one to the final condition
                        .take_while(|(_, ch)| {
                            // Fast return to iterate over final byte position
                            if ended {
                                return false;
                            }
                            // Make sure that the trimming on the right will fall within the terminal width.
                            // FIXME: `unicode_width` sometimes disagrees with terminals on how wide a `char` is.
                            // For now, just accept that sometimes the code line will be longer than desired.
                            taken += unicode_width::UnicodeWidthChar::width(*ch).unwrap_or(1);
                            if taken > right - left {
 return false;
 ended = true;
                            }
                            true
                        })
                        // Reduce to start and end byte position
                        .fold((None, 0), |acc, (i, _)| {
                            if acc.0.is_some() {
                                (acc.0, i)
                            }
                        });

                    text[range.0.expect("One character at line")..=range.1].fmt(f)?;
                    // Format text with margins
                    text[range.0.expect("One character at line")..range.1].fmt(f)?;

                    if cut_right {
                        // We have stripped some code after the right-most span end, make it clear we did so.
diff --git a/tests/fixtures/no-color/strip_line_char.toml b/tests/fixtures/no-color/strip_line_char.toml
 [title]
 id ="E0308"
 label ="mismatched types"
 annotation_type ="Error"

 [[slices]]
 source ="                                                                                                                                                                                    let _: () = 42ñ"
 line_start =4
 origin ="$DIR/whitespace-trimming.rs"

 [[slices.annotations]]
 label ="expected (), found integer"
 annotation_type ="Error"
 range = [192,194]

 [opt]
 color =false
 anonymized_line_numbers =true
 [opt.margin]
 whitespace_left =180
 span_left =192
 span_right =194
 label_right =221
 column_width =140
 max_line_len =195
diff --git a/tests/fixtures/no-color/strip_line_char.txt b/tests/fixtures/no-color/strip_line_char.txt
 error[E0308]: mismatched types
  --> $DIR/whitespace-trimming.rs:4:193
   |
 LL | ...                   let _: () = 42ñ
   |                                   ^^ expected (), found integer
   |
Original file line number	Diff line number	Diff line change
		@@ -1,6 +1,7 @@
		use std::{
		cmp,
		fmt::{self, Display, Write},
		iter::once,
		};

		pub mod style;
Expand DownExpand Up		@@ -217,19 +218,30 @@ impl<'a> DisplayList<'a> {
		} else {
		false
		};
		// Specifies that it will end on the next character, so it will return
		// until the next one to the final condition.
		let mut ended = false;
Copy link Contributor zbranieckiAug 24, 2020 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. can you document this variable? It's a bit unique. I also feel like there must be a way to make it simpler. The`range.0` is always the result of`acc.0`, so basically the first`take()`, and the`range.1` should be chainable`Option` on last element of`take_while` so if you put the iterator as a mutable variable, you should be able to do`iter.next().or(last)`. The refactor is optional, and I'm happy to land this as-is with a comment explaining the variable and its role. Copy link ContributorAuthor zzau13Aug 24, 2020 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. This`ended` specifies that it will end in the next character so it will return until the next one to the final condition. In order to measure this last character, when end condition is true, in an efficient way. I will try to document it. Copy link Contributor zbranieckiAug 24, 2020 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. I think I understand the role, but I had to run an iterator in my head to derive to that conclusion so a doc string would help. zzau13 reacted with thumbs up emoji
		let range = text
		.char_indices()
		.skip(left)
		// Complete char iterator with final character
		.chain(once((text.len(), '\0')))
		// Take until the next one to the final condition
		.take_while(\|(_, ch)\| {
		// Fast return to iterate over final byte position
		if ended {
		return false;
		}
		// Make sure that the trimming on the right will fall within the terminal width.
		// FIXME: `unicode_width` sometimes disagrees with terminals on how wide a `char` is.
		// For now, just accept that sometimes the code line will be longer than desired.
		taken += unicode_width::UnicodeWidthChar::width(*ch).unwrap_or(1);
		if taken > right - left {
		return false;
		ended = true;
		}
		true
		})
		// Reduce to start and end byte position
		.fold((None, 0), \|acc, (i, _)\| {
		if acc.0.is_some() {
		(acc.0, i)
Expand All		@@ -238,7 +250,8 @@ impl<'a> DisplayList<'a> {
		}
		});

		text[range.0.expect("One character at line")..=range.1].fmt(f)?;
		// Format text with margins
		text[range.0.expect("One character at line")..range.1].fmt(f)?;

		if cut_right {
		// We have stripped some code after the right-most span end, make it clear we did so.
Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,25 @@
		[title]
		id ="E0308"
		label ="mismatched types"
		annotation_type ="Error"

		[[slices]]
		source =" let _: () = 42ñ"
		line_start =4
		origin ="$DIR/whitespace-trimming.rs"

		[[slices.annotations]]
		label ="expected (), found integer"
		annotation_type ="Error"
		range = [192,194]

		[opt]
		color =false
		anonymized_line_numbers =true
		[opt.margin]
		whitespace_left =180
		span_left =192
		span_right =194
		label_right =221
		column_width =140
		max_line_len =195
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,6 @@
		error[E0308]: mismatched types
		--> $DIR/whitespace-trimming.rs:4:193
		\|
		LL \| ... let _: () = 42ñ
		\| ^^ expected (), found integer
		\|