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use std::io::{self, Write};
use std::ops::Range;
use termcolor::{ColorSpec, WriteColor};
use crate::diagnostic::{LabelStyle, Severity};
use crate::files::{Error, Location};
use crate::term::{Chars, Config, Styles};
/// The 'location focus' of a source code snippet.
pub struct Locus {
/// The user-facing name of the file.
pub name: String,
/// The location.
pub location: Location,
}
/// Single-line label, with an optional message.
///
/// ```text
/// ^^^^^^^^^ blah blah
/// ```
pub type SingleLabel<'diagnostic> = (LabelStyle, Range<usize>, &'diagnostic str);
/// A multi-line label to render.
///
/// Locations are relative to the start of where the source code is rendered.
pub enum MultiLabel<'diagnostic> {
/// Multi-line label top.
/// The contained value indicates where the label starts.
///
/// ```text
/// ╭────────────^
/// ```
///
/// Can also be rendered at the beginning of the line
/// if there is only whitespace before the label starts.
///
/// /// ```text
/// ╭
/// ```
Top(usize),
/// Left vertical labels for multi-line labels.
///
/// ```text
/// │
/// ```
Left,
/// Multi-line label bottom, with an optional message.
/// The first value indicates where the label ends.
///
/// ```text
/// ╰────────────^ blah blah
/// ```
Bottom(usize, &'diagnostic str),
}
#[derive(Copy, Clone)]
enum VerticalBound {
Top,
Bottom,
}
type Underline = (LabelStyle, VerticalBound);
/// A renderer of display list entries.
///
/// The following diagram gives an overview of each of the parts of the renderer's output:
///
/// ```text
/// ┌ outer gutter
/// │ ┌ left border
/// │ │ ┌ inner gutter
/// │ │ │ ┌─────────────────────────── source ─────────────────────────────┐
/// │ │ │ │ │
/// ┌────────────────────────────────────────────────────────────────────────────
/// header ── │ error[0001]: oh noes, a cupcake has occurred!
/// snippet start ── │ ┌─ test:9:0
/// snippet empty ── │ │
/// snippet line ── │ 9 │ ╭ Cupcake ipsum dolor. Sit amet marshmallow topping cheesecake
/// snippet line ── │ 10 │ │ muffin. Halvah croissant candy canes bonbon candy. Apple pie jelly
/// │ │ ╭─│─────────^
/// snippet break ── │ · │ │
/// snippet line ── │ 33 │ │ │ Muffin danish chocolate soufflé pastry icing bonbon oat cake.
/// snippet line ── │ 34 │ │ │ Powder cake jujubes oat cake. Lemon drops tootsie roll marshmallow
/// │ │ │ ╰─────────────────────────────^ blah blah
/// snippet break ── │ · │
/// snippet line ── │ 38 │ │ Brownie lemon drops chocolate jelly-o candy canes. Danish marzipan
/// snippet line ── │ 39 │ │ jujubes soufflé carrot cake marshmallow tiramisu caramels candy canes.
/// │ │ │ ^^^^^^^^^^^^^^^^^^^ -------------------- blah blah
/// │ │ │ │
/// │ │ │ blah blah
/// │ │ │ note: this is a note
/// snippet line ── │ 40 │ │ Fruitcake jelly-o danish toffee. Tootsie roll pastry cheesecake
/// snippet line ── │ 41 │ │ soufflé marzipan. Chocolate bar oat cake jujubes lollipop pastry
/// snippet line ── │ 42 │ │ cupcake. Candy canes cupcake toffee gingerbread candy canes muffin
/// │ │ │ ^^^^^^^^^^^^^^^^^^ blah blah
/// │ │ ╰──────────^ blah blah
/// snippet break ── │ ·
/// snippet line ── │ 82 │ gingerbread toffee chupa chups chupa chups jelly-o cotton candy.
/// │ │ ^^^^^^ ------- blah blah
/// snippet empty ── │ │
/// snippet note ── │ = blah blah
/// snippet note ── │ = blah blah blah
/// │ blah blah
/// snippet note ── │ = blah blah blah
/// │ blah blah
/// empty ── │
/// ```
///
pub struct Renderer<'writer, 'config> {
writer: &'writer mut dyn WriteColor,
config: &'config Config,
}
impl<'writer, 'config> Renderer<'writer, 'config> {
/// Construct a renderer from the given writer and config.
pub fn new(
writer: &'writer mut dyn WriteColor,
config: &'config Config,
) -> Renderer<'writer, 'config> {
Renderer { writer, config }
}
fn chars(&self) -> &'config Chars {
&self.config.chars
}
fn styles(&self) -> &'config Styles {
&self.config.styles
}
/// Diagnostic header, with severity, code, and message.
///
/// ```text
/// error[E0001]: unexpected type in `+` application
/// ```
pub fn render_header(
&mut self,
locus: Option<&Locus>,
severity: Severity,
code: Option<&str>,
message: &str,
) -> Result<(), Error> {
// Write locus
//
// ```text
// test:2:9:
// ```
if let Some(locus) = locus {
self.snippet_locus(locus)?;
write!(self, ": ")?;
}
// Write severity name
//
// ```text
// error
// ```
self.set_color(self.styles().header(severity))?;
match severity {
Severity::Bug => write!(self, "bug")?,
Severity::Error => write!(self, "error")?,
Severity::Warning => write!(self, "warning")?,
Severity::Help => write!(self, "help")?,
Severity::Note => write!(self, "note")?,
}
// Write error code
//
// ```text
// [E0001]
// ```
if let Some(code) = &code.filter(|code| !code.is_empty()) {
write!(self, "[{}]", code)?;
}
// Write diagnostic message
//
// ```text
// : unexpected type in `+` application
// ```
self.set_color(&self.styles().header_message)?;
write!(self, ": {}", message)?;
self.reset()?;
writeln!(self)?;
Ok(())
}
/// Empty line.
pub fn render_empty(&mut self) -> Result<(), Error> {
writeln!(self)?;
Ok(())
}
/// Top left border and locus.
///
/// ```text
/// ┌─ test:2:9
/// ```
pub fn render_snippet_start(
&mut self,
outer_padding: usize,
locus: &Locus,
) -> Result<(), Error> {
self.outer_gutter(outer_padding)?;
self.set_color(&self.styles().source_border)?;
write!(self, "{}", self.chars().snippet_start)?;
self.reset()?;
write!(self, " ")?;
self.snippet_locus(&locus)?;
writeln!(self)?;
Ok(())
}
/// A line of source code.
///
/// ```text
/// 10 │ │ muffin. Halvah croissant candy canes bonbon candy. Apple pie jelly
/// │ ╭─│─────────^
/// ```
pub fn render_snippet_source(
&mut self,
outer_padding: usize,
line_number: usize,
source: &str,
severity: Severity,
single_labels: &[SingleLabel<'_>],
num_multi_labels: usize,
multi_labels: &[(usize, LabelStyle, MultiLabel<'_>)],
) -> Result<(), Error> {
// Trim trailing newlines, linefeeds, and null chars from source, if they exist.
// FIXME: Use the number of trimmed placeholders when rendering single line carets
let source = source.trim_end_matches(['\n', '\r', '\0'].as_ref());
// Write source line
//
// ```text
// 10 │ │ muffin. Halvah croissant candy canes bonbon candy. Apple pie jelly
// ```
{
// Write outer gutter (with line number) and border
self.outer_gutter_number(line_number, outer_padding)?;
self.border_left()?;
// Write inner gutter (with multi-line continuations on the left if necessary)
let mut multi_labels_iter = multi_labels.iter().peekable();
for label_column in 0..num_multi_labels {
match multi_labels_iter.peek() {
Some((label_index, label_style, label)) if *label_index == label_column => {
match label {
MultiLabel::Top(start)
if *start <= source.len() - source.trim_start().len() =>
{
self.label_multi_top_left(severity, *label_style)?;
}
MultiLabel::Top(..) => self.inner_gutter_space()?,
MultiLabel::Left | MultiLabel::Bottom(..) => {
self.label_multi_left(severity, *label_style, None)?;
}
}
multi_labels_iter.next();
}
Some((_, _, _)) | None => self.inner_gutter_space()?,
}
}
// Write source text
write!(self, " ")?;
let mut in_primary = false;
for (metrics, ch) in self.char_metrics(source.char_indices()) {
let column_range = metrics.byte_index..(metrics.byte_index + ch.len_utf8());
// Check if we are overlapping a primary label
let is_primary = single_labels.iter().any(|(ls, range, _)| {
*ls == LabelStyle::Primary && is_overlapping(range, &column_range)
}) || multi_labels.iter().any(|(_, ls, label)| {
*ls == LabelStyle::Primary
&& match label {
MultiLabel::Top(start) => column_range.start >= *start,
MultiLabel::Left => true,
MultiLabel::Bottom(start, _) => column_range.end <= *start,
}
});
// Set the source color if we are in a primary label
if is_primary && !in_primary {
self.set_color(self.styles().label(severity, LabelStyle::Primary))?;
in_primary = true;
} else if !is_primary && in_primary {
self.reset()?;
in_primary = false;
}
match ch {
'\t' => (0..metrics.unicode_width).try_for_each(|_| write!(self, " "))?,
_ => write!(self, "{}", ch)?,
}
}
if in_primary {
self.reset()?;
}
writeln!(self)?;
}
// Write single labels underneath source
//
// ```text
// │ - ---- ^^^ second mutable borrow occurs here
// │ │ │
// │ │ first mutable borrow occurs here
// │ first borrow later used by call
// │ help: some help here
// ```
if !single_labels.is_empty() {
// Our plan is as follows:
//
// 1. Do an initial scan to find:
// - The number of non-empty messages.
// - The right-most start and end positions of labels.
// - A candidate for a trailing label (where the label's message
// is printed to the left of the caret).
// 2. Check if the trailing label candidate overlaps another label -
// if so we print it underneath the carets with the other labels.
// 3. Print a line of carets, and (possibly) the trailing message
// to the left.
// 4. Print vertical lines pointing to the carets, and the messages
// for those carets.
//
// We try our best avoid introducing new dynamic allocations,
// instead preferring to iterate over the labels multiple times. It
// is unclear what the performance tradeoffs are however, so further
// investigation may be required.
// The number of non-empty messages to print.
let mut num_messages = 0;
// The right-most start position, eg:
//
// ```text
// -^^^^---- ^^^^^^^
// │
// right-most start position
// ```
let mut max_label_start = 0;
// The right-most end position, eg:
//
// ```text
// -^^^^---- ^^^^^^^
// │
// right-most end position
// ```
let mut max_label_end = 0;
// A trailing message, eg:
//
// ```text
// ^^^ second mutable borrow occurs here
// ```
let mut trailing_label = None;
for (label_index, label) in single_labels.iter().enumerate() {
let (_, range, message) = label;
if !message.is_empty() {
num_messages += 1;
}
max_label_start = std::cmp::max(max_label_start, range.start);
max_label_end = std::cmp::max(max_label_end, range.end);
// This is a candidate for the trailing label, so let's record it.
if range.end == max_label_end {
if message.is_empty() {
trailing_label = None;
} else {
trailing_label = Some((label_index, label));
}
}
}
if let Some((trailing_label_index, (_, trailing_range, _))) = trailing_label {
// Check to see if the trailing label candidate overlaps any of
// the other labels on the current line.
if single_labels
.iter()
.enumerate()
.filter(|(label_index, _)| *label_index != trailing_label_index)
.any(|(_, (_, range, _))| is_overlapping(trailing_range, range))
{
// If it does, we'll instead want to render it below the
// carets along with the other hanging labels.
trailing_label = None;
}
}
// Write a line of carets
//
// ```text
// │ ^^^^^^ -------^^^^^^^^^-------^^^^^----- ^^^^ trailing label message
// ```
self.outer_gutter(outer_padding)?;
self.border_left()?;
self.inner_gutter(severity, num_multi_labels, multi_labels)?;
write!(self, " ")?;
let mut previous_label_style = None;
let placeholder_metrics = Metrics {
byte_index: source.len(),
unicode_width: 1,
};
for (metrics, ch) in self
.char_metrics(source.char_indices())
// Add a placeholder source column at the end to allow for
// printing carets at the end of lines, eg:
//
// ```text
// 1 │ Hello world!
// │ ^
// ```
.chain(std::iter::once((placeholder_metrics, '\0')))
{
// Find the current label style at this column
let column_range = metrics.byte_index..(metrics.byte_index + ch.len_utf8());
let current_label_style = single_labels
.iter()
.filter(|(_, range, _)| is_overlapping(range, &column_range))
.map(|(label_style, _, _)| *label_style)
.max_by_key(label_priority_key);
// Update writer style if necessary
if previous_label_style != current_label_style {
match current_label_style {
None => self.reset()?,
Some(label_style) => {
self.set_color(self.styles().label(severity, label_style))?;
}
}
}
let caret_ch = match current_label_style {
Some(LabelStyle::Primary) => Some(self.chars().single_primary_caret),
Some(LabelStyle::Secondary) => Some(self.chars().single_secondary_caret),
// Only print padding if we are before the end of the last single line caret
None if metrics.byte_index < max_label_end => Some(' '),
None => None,
};
if let Some(caret_ch) = caret_ch {
// FIXME: improve rendering of carets between character boundaries
(0..metrics.unicode_width).try_for_each(|_| write!(self, "{}", caret_ch))?;
}
previous_label_style = current_label_style;
}
// Reset style if it was previously set
if previous_label_style.is_some() {
self.reset()?;
}
// Write first trailing label message
if let Some((_, (label_style, _, message))) = trailing_label {
write!(self, " ")?;
self.set_color(self.styles().label(severity, *label_style))?;
write!(self, "{}", message)?;
self.reset()?;
}
writeln!(self)?;
// Write hanging labels pointing to carets
//
// ```text
// │ │ │
// │ │ first mutable borrow occurs here
// │ first borrow later used by call
// │ help: some help here
// ```
if num_messages > trailing_label.iter().count() {
// Write first set of vertical lines before hanging labels
//
// ```text
// │ │ │
// ```
self.outer_gutter(outer_padding)?;
self.border_left()?;
self.inner_gutter(severity, num_multi_labels, multi_labels)?;
write!(self, " ")?;
self.caret_pointers(
severity,
max_label_start,
single_labels,
trailing_label,
source.char_indices(),
)?;
writeln!(self)?;
// Write hanging labels pointing to carets
//
// ```text
// │ │ first mutable borrow occurs here
// │ first borrow later used by call
// │ help: some help here
// ```
for (label_style, range, message) in
hanging_labels(single_labels, trailing_label).rev()
{
self.outer_gutter(outer_padding)?;
self.border_left()?;
self.inner_gutter(severity, num_multi_labels, multi_labels)?;
write!(self, " ")?;
self.caret_pointers(
severity,
max_label_start,
single_labels,
trailing_label,
source
.char_indices()
.take_while(|(byte_index, _)| *byte_index < range.start),
)?;
self.set_color(self.styles().label(severity, *label_style))?;
write!(self, "{}", message)?;
self.reset()?;
writeln!(self)?;
}
}
}
// Write top or bottom label carets underneath source
//
// ```text
// │ ╰───│──────────────────^ woops
// │ ╭─│─────────^
// ```
for (multi_label_index, (_, label_style, label)) in multi_labels.iter().enumerate() {
let (label_style, range, bottom_message) = match label {
MultiLabel::Left => continue, // no label caret needed
// no label caret needed if this can be started in front of the line
MultiLabel::Top(start) if *start <= source.len() - source.trim_start().len() => {
continue
}
MultiLabel::Top(range) => (*label_style, range, None),
MultiLabel::Bottom(range, message) => (*label_style, range, Some(message)),
};
self.outer_gutter(outer_padding)?;
self.border_left()?;
// Write inner gutter.
//
// ```text
// │ ╭─│───│
// ```
let mut underline = None;
let mut multi_labels_iter = multi_labels.iter().enumerate().peekable();
for label_column in 0..num_multi_labels {
match multi_labels_iter.peek() {
Some((i, (label_index, ls, label))) if *label_index == label_column => {
match label {
MultiLabel::Left => {
self.label_multi_left(severity, *ls, underline.map(|(s, _)| s))?;
}
MultiLabel::Top(..) if multi_label_index > *i => {
self.label_multi_left(severity, *ls, underline.map(|(s, _)| s))?;
}
MultiLabel::Bottom(..) if multi_label_index < *i => {
self.label_multi_left(severity, *ls, underline.map(|(s, _)| s))?;
}
MultiLabel::Top(..) if multi_label_index == *i => {
underline = Some((*ls, VerticalBound::Top));
self.label_multi_top_left(severity, label_style)?
}
MultiLabel::Bottom(..) if multi_label_index == *i => {
underline = Some((*ls, VerticalBound::Bottom));
self.label_multi_bottom_left(severity, label_style)?;
}
MultiLabel::Top(..) | MultiLabel::Bottom(..) => {
self.inner_gutter_column(severity, underline)?;
}
}
multi_labels_iter.next();
}
Some((_, _)) | None => self.inner_gutter_column(severity, underline)?,
}
}
// Finish the top or bottom caret
match bottom_message {
None => self.label_multi_top_caret(severity, label_style, source, *range)?,
Some(message) => {
self.label_multi_bottom_caret(severity, label_style, source, *range, message)?
}
}
}
Ok(())
}
/// An empty source line, for providing additional whitespace to source snippets.
///
/// ```text
/// │ │ │
/// ```
pub fn render_snippet_empty(
&mut self,
outer_padding: usize,
severity: Severity,
num_multi_labels: usize,
multi_labels: &[(usize, LabelStyle, MultiLabel<'_>)],
) -> Result<(), Error> {
self.outer_gutter(outer_padding)?;
self.border_left()?;
self.inner_gutter(severity, num_multi_labels, multi_labels)?;
writeln!(self)?;
Ok(())
}
/// A broken source line, for labeling skipped sections of source.
///
/// ```text
/// · │ │
/// ```
pub fn render_snippet_break(
&mut self,
outer_padding: usize,
severity: Severity,
num_multi_labels: usize,
multi_labels: &[(usize, LabelStyle, MultiLabel<'_>)],
) -> Result<(), Error> {
self.outer_gutter(outer_padding)?;
self.border_left_break()?;
self.inner_gutter(severity, num_multi_labels, multi_labels)?;
writeln!(self)?;
Ok(())
}
/// Additional notes.
///
/// ```text
/// = expected type `Int`
/// found type `String`
/// ```
pub fn render_snippet_note(
&mut self,
outer_padding: usize,
message: &str,
) -> Result<(), Error> {
for (note_line_index, line) in message.lines().enumerate() {
self.outer_gutter(outer_padding)?;
match note_line_index {
0 => {
self.set_color(&self.styles().note_bullet)?;
write!(self, "{}", self.chars().note_bullet)?;
self.reset()?;
}
_ => write!(self, " ")?,
}
// Write line of message
writeln!(self, " {}", line)?;
}
Ok(())
}
/// Adds tab-stop aware unicode-width computations to an iterator over
/// character indices. Assumes that the character indices begin at the start
/// of the line.
fn char_metrics(
&self,
char_indices: impl Iterator<Item = (usize, char)>,
) -> impl Iterator<Item = (Metrics, char)> {
use unicode_width::UnicodeWidthChar;
let tab_width = self.config.tab_width;
let mut unicode_column = 0;
char_indices.map(move |(byte_index, ch)| {
let metrics = Metrics {
byte_index,
unicode_width: match (ch, tab_width) {
('\t', 0) => 0, // Guard divide-by-zero
('\t', _) => tab_width - (unicode_column % tab_width),
(ch, _) => ch.width().unwrap_or(0),
},
};
unicode_column += metrics.unicode_width;
(metrics, ch)
})
}
/// Location focus.
fn snippet_locus(&mut self, locus: &Locus) -> Result<(), Error> {
write!(
self,
"{name}:{line_number}:{column_number}",
name = locus.name,
line_number = locus.location.line_number,
column_number = locus.location.column_number,
)?;
Ok(())
}
/// The outer gutter of a source line.
fn outer_gutter(&mut self, outer_padding: usize) -> Result<(), Error> {
write!(self, "{space: >width$} ", space = "", width = outer_padding)?;
Ok(())
}
/// The outer gutter of a source line, with line number.
fn outer_gutter_number(
&mut self,
line_number: usize,
outer_padding: usize,
) -> Result<(), Error> {
self.set_color(&self.styles().line_number)?;
write!(
self,
"{line_number: >width$}",
line_number = line_number,
width = outer_padding,
)?;
self.reset()?;
write!(self, " ")?;
Ok(())
}
/// The left-hand border of a source line.
fn border_left(&mut self) -> Result<(), Error> {
self.set_color(&self.styles().source_border)?;
write!(self, "{}", self.chars().source_border_left)?;
self.reset()?;
Ok(())
}
/// The broken left-hand border of a source line.
fn border_left_break(&mut self) -> Result<(), Error> {
self.set_color(&self.styles().source_border)?;
write!(self, "{}", self.chars().source_border_left_break)?;
self.reset()?;
Ok(())
}
/// Write vertical lines pointing to carets.
fn caret_pointers(
&mut self,
severity: Severity,
max_label_start: usize,
single_labels: &[SingleLabel<'_>],
trailing_label: Option<(usize, &SingleLabel<'_>)>,
char_indices: impl Iterator<Item = (usize, char)>,
) -> Result<(), Error> {
for (metrics, ch) in self.char_metrics(char_indices) {
let column_range = metrics.byte_index..(metrics.byte_index + ch.len_utf8());
let label_style = hanging_labels(single_labels, trailing_label)
.filter(|(_, range, _)| column_range.contains(&range.start))
.map(|(label_style, _, _)| *label_style)
.max_by_key(label_priority_key);
let mut spaces = match label_style {
None => 0..metrics.unicode_width,
Some(label_style) => {
self.set_color(self.styles().label(severity, label_style))?;
write!(self, "{}", self.chars().pointer_left)?;
self.reset()?;
1..metrics.unicode_width
}
};
// Only print padding if we are before the end of the last single line caret
if metrics.byte_index <= max_label_start {
spaces.try_for_each(|_| write!(self, " "))?;
}
}
Ok(())
}
/// The left of a multi-line label.
///
/// ```text
/// │
/// ```
fn label_multi_left(
&mut self,
severity: Severity,
label_style: LabelStyle,
underline: Option<LabelStyle>,
) -> Result<(), Error> {
match underline {
None => write!(self, " ")?,
// Continue an underline horizontally
Some(label_style) => {
self.set_color(self.styles().label(severity, label_style))?;
write!(self, "{}", self.chars().multi_top)?;
self.reset()?;
}
}
self.set_color(self.styles().label(severity, label_style))?;
write!(self, "{}", self.chars().multi_left)?;
self.reset()?;
Ok(())
}
/// The top-left of a multi-line label.
///
/// ```text
/// ╭
/// ```
fn label_multi_top_left(
&mut self,
severity: Severity,
label_style: LabelStyle,
) -> Result<(), Error> {
write!(self, " ")?;
self.set_color(self.styles().label(severity, label_style))?;
write!(self, "{}", self.chars().multi_top_left)?;
self.reset()?;
Ok(())
}
/// The bottom left of a multi-line label.
///
/// ```text
/// ╰
/// ```
fn label_multi_bottom_left(
&mut self,
severity: Severity,
label_style: LabelStyle,
) -> Result<(), Error> {
write!(self, " ")?;
self.set_color(self.styles().label(severity, label_style))?;
write!(self, "{}", self.chars().multi_bottom_left)?;
self.reset()?;
Ok(())
}
/// Multi-line label top.
///
/// ```text
/// ─────────────^
/// ```
fn label_multi_top_caret(
&mut self,
severity: Severity,
label_style: LabelStyle,
source: &str,
start: usize,
) -> Result<(), Error> {
self.set_color(self.styles().label(severity, label_style))?;
for (metrics, _) in self
.char_metrics(source.char_indices())
.take_while(|(metrics, _)| metrics.byte_index < start + 1)
{
// FIXME: improve rendering of carets between character boundaries
(0..metrics.unicode_width)
.try_for_each(|_| write!(self, "{}", self.chars().multi_top))?;
}
let caret_start = match label_style {
LabelStyle::Primary => self.config.chars.multi_primary_caret_start,
LabelStyle::Secondary => self.config.chars.multi_secondary_caret_start,
};
write!(self, "{}", caret_start)?;
self.reset()?;
writeln!(self)?;
Ok(())
}
/// Multi-line label bottom, with a message.
///
/// ```text
/// ─────────────^ expected `Int` but found `String`
/// ```
fn label_multi_bottom_caret(
&mut self,
severity: Severity,
label_style: LabelStyle,
source: &str,
start: usize,
message: &str,
) -> Result<(), Error> {
self.set_color(self.styles().label(severity, label_style))?;
for (metrics, _) in self
.char_metrics(source.char_indices())
.take_while(|(metrics, _)| metrics.byte_index < start)
{
// FIXME: improve rendering of carets between character boundaries
(0..metrics.unicode_width)
.try_for_each(|_| write!(self, "{}", self.chars().multi_bottom))?;
}
let caret_end = match label_style {
LabelStyle::Primary => self.config.chars.multi_primary_caret_start,
LabelStyle::Secondary => self.config.chars.multi_secondary_caret_start,
};
write!(self, "{}", caret_end)?;
if !message.is_empty() {
write!(self, " {}", message)?;
}
self.reset()?;
writeln!(self)?;
Ok(())
}
/// Writes an empty gutter space, or continues an underline horizontally.
fn inner_gutter_column(
&mut self,
severity: Severity,
underline: Option<Underline>,
) -> Result<(), Error> {
match underline {
None => self.inner_gutter_space(),
Some((label_style, vertical_bound)) => {
self.set_color(self.styles().label(severity, label_style))?;
let ch = match vertical_bound {
VerticalBound::Top => self.config.chars.multi_top,
VerticalBound::Bottom => self.config.chars.multi_bottom,
};
write!(self, "{0}{0}", ch)?;
self.reset()?;
Ok(())
}
}
}
/// Writes an empty gutter space.
fn inner_gutter_space(&mut self) -> Result<(), Error> {
write!(self, " ")?;
Ok(())
}
/// Writes an inner gutter, with the left lines if necessary.
fn inner_gutter(
&mut self,
severity: Severity,
num_multi_labels: usize,
multi_labels: &[(usize, LabelStyle, MultiLabel<'_>)],
) -> Result<(), Error> {
let mut multi_labels_iter = multi_labels.iter().peekable();
for label_column in 0..num_multi_labels {
match multi_labels_iter.peek() {
Some((label_index, ls, label)) if *label_index == label_column => match label {
MultiLabel::Left | MultiLabel::Bottom(..) => {
self.label_multi_left(severity, *ls, None)?;
multi_labels_iter.next();
}
MultiLabel::Top(..) => {
self.inner_gutter_space()?;
multi_labels_iter.next();
}
},
Some((_, _, _)) | None => self.inner_gutter_space()?,
}
}
Ok(())
}
}
impl<'writer, 'config> Write for Renderer<'writer, 'config> {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.writer.write(buf)
}
fn flush(&mut self) -> io::Result<()> {
self.writer.flush()
}
}
impl<'writer, 'config> WriteColor for Renderer<'writer, 'config> {
fn supports_color(&self) -> bool {
self.writer.supports_color()
}
fn set_color(&mut self, spec: &ColorSpec) -> io::Result<()> {
self.writer.set_color(spec)
}
fn reset(&mut self) -> io::Result<()> {
self.writer.reset()
}
fn is_synchronous(&self) -> bool {
self.writer.is_synchronous()
}
}
struct Metrics {
byte_index: usize,
unicode_width: usize,
}
/// Check if two ranges overlap
fn is_overlapping(range0: &Range<usize>, range1: &Range<usize>) -> bool {
let start = std::cmp::max(range0.start, range1.start);
let end = std::cmp::min(range0.end, range1.end);
start < end
}
/// For prioritizing primary labels over secondary labels when rendering carets.
fn label_priority_key(label_style: &LabelStyle) -> u8 {
match label_style {
LabelStyle::Secondary => 0,
LabelStyle::Primary => 1,
}
}
/// Return an iterator that yields the labels that require hanging messages
/// rendered underneath them.
fn hanging_labels<'labels, 'diagnostic>(
single_labels: &'labels [SingleLabel<'diagnostic>],
trailing_label: Option<(usize, &'labels SingleLabel<'diagnostic>)>,
) -> impl 'labels + DoubleEndedIterator<Item = &'labels SingleLabel<'diagnostic>> {
single_labels
.iter()
.enumerate()
.filter(|(_, (_, _, message))| !message.is_empty())
.filter(move |(i, _)| trailing_label.map_or(true, |(j, _)| *i != j))
.map(|(_, label)| label)
}