refactor(#184)

src/renderer/display/constants.rs

@@ -0,0 +1,6 @@
+pub(crate) const ANONYMIZED_LINE_NUM: &str = "LL";
+pub(crate) const ERROR_TXT: &str = "error";
+pub(crate) const HELP_TXT: &str = "help";
+pub(crate) const INFO_TXT: &str = "info";
+pub(crate) const NOTE_TXT: &str = "note";
+pub(crate) const WARNING_TXT: &str = "warning";

src/renderer/display/cursor_line.rs

@@ -0,0 +1,40 @@
+use super::end_line::EndLine;
+
+pub(crate) struct CursorLines<'a>(&'a str);
+
+impl CursorLines<'_> {
+    pub(crate) fn new(src: &str) -> CursorLines<'_> {
+        CursorLines(src)
+    }
+}
+
+impl<'a> Iterator for CursorLines<'a> {
+    type Item = (&'a str, EndLine);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.0.is_empty() {
+            None
+        } else {
+            self.0
+                .find('\n')
+                .map(|x| {
+                    let ret = if 0 < x {
+                        if self.0.as_bytes()[x - 1] == b'\r' {
+                            (&self.0[..x - 1], EndLine::Crlf)
+                        } else {
+                            (&self.0[..x], EndLine::Lf)
+                        }
+                    } else {
+                        ("", EndLine::Lf)
+                    };
+                    self.0 = &self.0[x + 1..];
+                    ret
+                })
+                .or_else(|| {
+                    let ret = Some((self.0, EndLine::Eof));
+                    self.0 = "";
+                    ret
+                })
+        }
+    }
+}

src/renderer/display/display_annotations.rs

@@ -0,0 +1,140 @@
+use anstyle::Style;
+
+use crate::{renderer::stylesheet::Stylesheet, snippet};
+
+use super::{
+    constants::{ERROR_TXT, HELP_TXT, INFO_TXT, NOTE_TXT, WARNING_TXT},
+    display_text::DisplayTextFragment,
+};
+
+/// A type of the `Annotation` which may impact the sigils, style or text displayed.
+///
+/// There are several ways to uses this information when formatting the `DisplayList`:
+///
+/// * An annotation may display the name of the type like `error` or `info`.
+/// * An underline for `Error` may be `^^^` while for `Warning` it could be `---`.
+/// * `ColorStylesheet` may use different colors for different annotations.
+#[derive(Debug, Clone, PartialEq)]
+pub(crate) enum DisplayAnnotationType {
+    None,
+    Error,
+    Warning,
+    Info,
+    Note,
+    Help,
+}
+
+/// An inline text
+/// An indicator of what part of the annotation a given `Annotation` is.
+#[derive(Debug, Clone, PartialEq)]
+pub(crate) enum DisplayAnnotationPart {
+    /// A standalone, single-line annotation.
+    Standalone,
+    /// A continuation of a multi-line label of an annotation.
+    LabelContinuation,
+    /// A line starting a multiline annotation.
+    MultilineStart(usize),
+    /// A line ending a multiline annotation.
+    MultilineEnd(usize),
+}
+
+/// Inline annotation which can be used in either Raw or Source line.
+#[derive(Clone, Debug, PartialEq)]
+pub(crate) struct Annotation<'a> {
+    pub(crate) annotation_type: DisplayAnnotationType,
+    pub(crate) id: Option<&'a str>,
+    pub(crate) label: Vec<DisplayTextFragment<'a>>,
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub(crate) struct DisplaySourceAnnotation<'a> {
+    pub(crate) annotation: Annotation<'a>,
+    pub(crate) range: (usize, usize),
+    pub(crate) annotation_type: DisplayAnnotationType,
+    pub(crate) annotation_part: DisplayAnnotationPart,
+}
+
+impl DisplaySourceAnnotation<'_> {
+    pub(crate) fn has_label(&self) -> bool {
+        !self
+            .annotation
+            .label
+            .iter()
+            .all(|label| label.content.is_empty())
+    }
+
+    // Length of this annotation as displayed in the stderr output
+    pub(crate) fn len(&self) -> usize {
+        // Account for usize underflows
+        if self.range.1 > self.range.0 {
+            self.range.1 - self.range.0
+        } else {
+            self.range.0 - self.range.1
+        }
+    }
+
+    pub(crate) fn takes_space(&self) -> bool {
+        // Multiline annotations always have to keep vertical space.
+        matches!(
+            self.annotation_part,
+            DisplayAnnotationPart::MultilineStart(_) | DisplayAnnotationPart::MultilineEnd(_)
+        )
+    }
+}
+
+impl From<snippet::Level> for DisplayAnnotationType {
+    fn from(at: snippet::Level) -> Self {
+        match at {
+            snippet::Level::Error => DisplayAnnotationType::Error,
+            snippet::Level::Warning => DisplayAnnotationType::Warning,
+            snippet::Level::Info => DisplayAnnotationType::Info,
+            snippet::Level::Note => DisplayAnnotationType::Note,
+            snippet::Level::Help => DisplayAnnotationType::Help,
+        }
+    }
+}
+
+#[inline]
+pub(crate) fn annotation_type_str(annotation_type: &DisplayAnnotationType) -> &'static str {
+    match annotation_type {
+        DisplayAnnotationType::Error => ERROR_TXT,
+        DisplayAnnotationType::Help => HELP_TXT,
+        DisplayAnnotationType::Info => INFO_TXT,
+        DisplayAnnotationType::Note => NOTE_TXT,
+        DisplayAnnotationType::Warning => WARNING_TXT,
+        DisplayAnnotationType::None => "",
+    }
+}
+
+pub(crate) fn annotation_type_len(annotation_type: &DisplayAnnotationType) -> usize {
+    match annotation_type {
+        DisplayAnnotationType::Error => ERROR_TXT.len(),
+        DisplayAnnotationType::Help => HELP_TXT.len(),
+        DisplayAnnotationType::Info => INFO_TXT.len(),
+        DisplayAnnotationType::Note => NOTE_TXT.len(),
+        DisplayAnnotationType::Warning => WARNING_TXT.len(),
+        DisplayAnnotationType::None => 0,
+    }
+}
+
+pub(crate) fn get_annotation_style<'a>(
+    annotation_type: &DisplayAnnotationType,
+    stylesheet: &'a Stylesheet,
+) -> &'a Style {
+    match annotation_type {
+        DisplayAnnotationType::Error => stylesheet.error(),
+        DisplayAnnotationType::Warning => stylesheet.warning(),
+        DisplayAnnotationType::Info => stylesheet.info(),
+        DisplayAnnotationType::Note => stylesheet.note(),
+        DisplayAnnotationType::Help => stylesheet.help(),
+        DisplayAnnotationType::None => stylesheet.none(),
+    }
+}
+
+#[inline]
+pub(crate) fn is_annotation_empty(annotation: &Annotation<'_>) -> bool {
+    annotation
+        .label
+        .iter()
+        .all(|fragment| fragment.content.is_empty())
+}

src/renderer/display/display_header.rs

@@ -0,0 +1,11 @@
+/// Information whether the header is the initial one or a consequitive one
+/// for multi-slice cases.
+// TODO: private
+#[derive(Debug, Clone, PartialEq)]
+pub(crate) enum DisplayHeaderType {
+    /// Initial header is the first header in the snippet.
+    Initial,
+
+    /// Continuation marks all headers of following slices in the snippet.
+    Continuation,
+}

src/renderer/display/display_line.rs

@@ -0,0 +1,64 @@
+use super::{
+    display_annotations::{Annotation, DisplaySourceAnnotation},
+    display_header::DisplayHeaderType,
+    display_mark::DisplayMark,
+    end_line::EndLine,
+};
+
+/// A single line used in `DisplayList`.
+#[derive(Debug, PartialEq)]
+pub(crate) enum DisplayLine<'a> {
+    /// A line with `lineno` portion of the slice.
+    Source {
+        lineno: Option<usize>,
+        inline_marks: Vec<DisplayMark>,
+        line: DisplaySourceLine<'a>,
+        annotations: Vec<DisplaySourceAnnotation<'a>>,
+    },
+
+    /// A line indicating a folded part of the slice.
+    Fold { inline_marks: Vec<DisplayMark> },
+
+    /// A line which is displayed outside of slices.
+    Raw(DisplayRawLine<'a>),
+}
+
+/// A source line.
+#[derive(Debug, PartialEq)]
+pub(crate) enum DisplaySourceLine<'a> {
+    /// A line with the content of the Snippet.
+    Content {
+        text: &'a str,
+        range: (usize, usize), // meta information for annotation placement.
+        end_line: EndLine,
+    },
+    /// An empty source line.
+    Empty,
+}
+
+/// Raw line - a line which does not have the `lineno` part and is not considered
+/// a part of the snippet.
+#[derive(Debug, PartialEq)]
+pub(crate) enum DisplayRawLine<'a> {
+    /// A line which provides information about the location of the given
+    /// slice in the project structure.
+    Origin {
+        path: &'a str,
+        pos: Option<(usize, usize)>,
+        header_type: DisplayHeaderType,
+    },
+
+    /// An annotation line which is not part of any snippet.
+    Annotation {
+        annotation: Annotation<'a>,
+
+        /// If set to `true`, the annotation will be aligned to the
+        /// lineno delimiter of the snippet.
+        source_aligned: bool,
+        /// If set to `true`, only the label of the `Annotation` will be
+        /// displayed. It allows for a multiline annotation to be aligned
+        /// without displaying the meta information (`type` and `id`) to be
+        /// displayed on each line.
+        continuation: bool,
+    },
+}

src/renderer/display/display_list.rs

@@ -0,0 +1,120 @@
+use std::{
+    cmp,
+    fmt::{self, Display},
+};
+
+use crate::{
+    renderer::{
+        display::{
+            constants::ANONYMIZED_LINE_NUM, display_annotations::DisplayAnnotationPart,
+            display_line::DisplayLine,
+        },
+        styled_buffer::StyledBuffer,
+        stylesheet::Stylesheet,
+    },
+    snippet,
+};
+
+use super::{display_set::DisplaySet, format_message};
+
+/// List of lines to be displayed.
+pub(crate) struct DisplayList<'a> {
+    pub(crate) body: Vec<DisplaySet<'a>>,
+    pub(crate) stylesheet: &'a Stylesheet,
+    pub(crate) anonymized_line_numbers: bool,
+}
+
+impl PartialEq for DisplayList<'_> {
+    fn eq(&self, other: &Self) -> bool {
+        self.body == other.body && self.anonymized_line_numbers == other.anonymized_line_numbers
+    }
+}
+
+impl fmt::Debug for DisplayList<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("DisplayList")
+            .field("body", &self.body)
+            .field("anonymized_line_numbers", &self.anonymized_line_numbers)
+            .finish()
+    }
+}
+
+impl Display for DisplayList<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let lineno_width = self.body.iter().fold(0, |max, set| {
+            set.display_lines.iter().fold(max, |max, line| match line {
+                DisplayLine::Source { lineno, .. } => cmp::max(lineno.unwrap_or(0), max),
+                _ => max,
+            })
+        });
+        let lineno_width = if lineno_width == 0 {
+            lineno_width
+        } else if self.anonymized_line_numbers {
+            ANONYMIZED_LINE_NUM.len()
+        } else {
+            ((lineno_width as f64).log10().floor() as usize) + 1
+        };
+
+        let multiline_depth = self.body.iter().fold(0, |max, set| {
+            set.display_lines.iter().fold(max, |max2, line| match line {
+                DisplayLine::Source { annotations, .. } => cmp::max(
+                    annotations.iter().fold(max2, |max3, line| {
+                        cmp::max(
+                            match line.annotation_part {
+                                DisplayAnnotationPart::Standalone => 0,
+                                DisplayAnnotationPart::LabelContinuation => 0,
+                                DisplayAnnotationPart::MultilineStart(depth) => depth + 1,
+                                DisplayAnnotationPart::MultilineEnd(depth) => depth + 1,
+                            },
+                            max3,
+                        )
+                    }),
+                    max,
+                ),
+                _ => max2,
+            })
+        });
+        let mut buffer = StyledBuffer::new();
+        for set in self.body.iter() {
+            self.format_set(set, lineno_width, multiline_depth, &mut buffer)?;
+        }
+        write!(f, "{}", buffer.render(self.stylesheet)?)
+    }
+}
+
+impl<'a> DisplayList<'a> {
+    pub(crate) fn new(
+        message: snippet::Message<'a>,
+        stylesheet: &'a Stylesheet,
+        anonymized_line_numbers: bool,
+        term_width: usize,
+    ) -> DisplayList<'a> {
+        let body = format_message(message, term_width, anonymized_line_numbers, true);
+
+        Self {
+            body,
+            stylesheet,
+            anonymized_line_numbers,
+        }
+    }
+
+    fn format_set(
+        &self,
+        set: &DisplaySet<'_>,
+        lineno_width: usize,
+        multiline_depth: usize,
+        buffer: &mut StyledBuffer,
+    ) -> fmt::Result {
+        for line in &set.display_lines {
+            set.format_line(
+                line,
+                lineno_width,
+                multiline_depth,
+                self.stylesheet,
+                self.anonymized_line_numbers,
+                buffer,
+            )?;
+        }
+        Ok(())
+    }
+}