printer: implement --max-columns-preview-before

crates/core/flags/defs.rs

@@ -92,6 +92,7 @@ pub(super) const FLAGS: &[&dyn Flag] = &[
     &LineRegexp,
     &MaxColumns,
     &MaxColumnsPreview,
+    &MaxColumnsPreviewBefore,
     &MaxCount,
     &MaxDepth,
     &MaxFilesize,
@@ -118,6 +119,7 @@ pub(super) const FLAGS: &[&dyn Flag] = &[
     &Passthru,
     &PCRE2,
     &PCRE2Version,
+    &PerMatch,
     &Pre,
     &PreGlob,
     &Pretty,
@@ -3782,6 +3784,53 @@ fn test_max_columns_preview() {
     assert_eq!(false, args.max_columns_preview);
 }
 
+/// --max-columns-preview-before
+#[derive(Debug)]
+struct MaxColumnsPreviewBefore;
+
+impl Flag for MaxColumnsPreviewBefore {
+    fn is_switch(&self) -> bool {
+        false
+    }
+    fn name_long(&self) -> &'static str {
+        "max-columns-preview-before"
+    }
+    fn doc_variable(&self) -> Option<&'static str> {
+        Some("NUM")
+    }
+    fn doc_category(&self) -> Category {
+        Category::Output
+    }
+    fn doc_short(&self) -> &'static str {
+        r"Columns to be printed before the first match in the preview."
+    }
+    fn doc_long(&self) -> &'static str {
+        r"
+Set the maximum amount of columns before the first match should be printed in
+the preview.
+.sp
+When the \flag{max-columns-preview} flag is used, ripgrep will print a preview
+start from the beginning of the line. When this flag is combined with
+\flag{max-columns-preview}, the preview will start \fINUM\fP columns before the
+first match.
+.sp
+If the \flag{max-columns-preview} flag is not set, then this has no effect.
+"
+    }
+
+    fn update(&self, v: FlagValue, args: &mut LowArgs) -> anyhow::Result<()> {
+        args.max_columns_preview_before =
+            Some(convert::u64(&v.unwrap_value())?);
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+#[test]
+fn test_max_columns_preview_before() {
+    // TODO
+}
+
 /// -m/--max-count
 #[derive(Debug)]
 struct MaxCount;
@@ -5349,6 +5398,42 @@ fn test_pcre2_version() {
     assert_eq!(Some(SpecialMode::VersionPCRE2), args.special);
 }
 
+/// --per-match
+#[derive(Debug)]
+struct PerMatch;
+
+impl Flag for PerMatch {
+    fn is_switch(&self) -> bool {
+        true
+    }
+    fn name_long(&self) -> &'static str {
+        "per-match"
+    }
+    fn doc_category(&self) -> Category {
+        Category::Output
+    }
+    fn doc_short(&self) -> &'static str {
+        r"TODO"
+    }
+    fn doc_long(&self) -> &'static str {
+        r"
+TODO
+"
+    }
+
+    fn update(&self, v: FlagValue, args: &mut LowArgs) -> anyhow::Result<()> {
+        assert!(v.unwrap_switch(), "--per-match does not have a negation");
+        args.per_match = true;
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+#[test]
+fn test_per_match() {
+    // TODO
+}
+
 /// --pre
 #[derive(Debug)]
 struct Pre;

crates/core/flags/hiargs.rs

@@ -65,6 +65,7 @@ pub(crate) struct HiArgs {
     line_number: bool,
     max_columns: Option<u64>,
     max_columns_preview: bool,
+    max_columns_preview_before: Option<u64>,
     max_count: Option<u64>,
     max_depth: Option<usize>,
     max_filesize: Option<u64>,
@@ -87,6 +88,7 @@ pub(crate) struct HiArgs {
     paths: Paths,
     path_terminator: Option<u8>,
     patterns: Patterns,
+    per_match: bool,
     pre: Option<PathBuf>,
     pre_globs: ignore::overrides::Override,
     quiet: bool,
@@ -281,6 +283,7 @@ impl HiArgs {
             line_number,
             max_columns: low.max_columns,
             max_columns_preview: low.max_columns_preview,
+            max_columns_preview_before: low.max_columns_preview_before,
             max_count: low.max_count,
             max_depth: low.max_depth,
             max_filesize: low.max_filesize,
@@ -301,6 +304,7 @@ impl HiArgs {
             globs,
             path_separator: low.path_separator,
             path_terminator,
+            per_match: low.per_match,
             pre: low.pre,
             pre_globs,
             quiet: low.quiet,
@@ -606,13 +610,14 @@ impl HiArgs {
             .heading(self.heading)
             .hyperlink(self.hyperlink_config.clone())
             .max_columns_preview(self.max_columns_preview)
+            .max_columns_preview_before(self.max_columns_preview_before)
             .max_columns(self.max_columns)
             .max_matches(self.max_count)
             .only_matching(self.only_matching)
             .path(self.with_filename)
             .path_terminator(self.path_terminator.clone())
             .per_match_one_line(true)
-            .per_match(self.vimgrep)
+            .per_match(self.per_match || self.vimgrep)
             .replacement(self.replace.clone().map(|r| r.into()))
             .separator_context(self.context_separator.clone().into_bytes())
             .separator_field_context(

crates/core/flags/lowargs.rs

@@ -70,6 +70,7 @@ pub(crate) struct LowArgs {
     pub(crate) logging: Option<LoggingMode>,
     pub(crate) max_columns: Option<u64>,
     pub(crate) max_columns_preview: bool,
+    pub(crate) max_columns_preview_before: Option<u64>,
     pub(crate) max_count: Option<u64>,
     pub(crate) max_depth: Option<usize>,
     pub(crate) max_filesize: Option<u64>,
@@ -92,6 +93,7 @@ pub(crate) struct LowArgs {
     pub(crate) one_file_system: bool,
     pub(crate) only_matching: bool,
     pub(crate) path_separator: Option<u8>,
+    pub(crate) per_match: bool,
     pub(crate) pre: Option<PathBuf>,
     pub(crate) pre_glob: Vec<String>,
     pub(crate) quiet: bool,

crates/printer/src/standard.rs

@@ -46,6 +46,7 @@ struct Config {
     replacement: Arc<Option<Vec<u8>>>,
     max_columns: Option<u64>,
     max_columns_preview: bool,
+    max_columns_preview_before: Option<u64>,
     max_matches: Option<u64>,
     column: bool,
     byte_offset: bool,
@@ -72,6 +73,7 @@ impl Default for Config {
             replacement: Arc::new(None),
             max_columns: None,
             max_columns_preview: false,
+            max_columns_preview_before: None,
             max_matches: None,
             column: false,
             byte_offset: false,
@@ -326,6 +328,19 @@ impl StandardBuilder {
         self
     }
 
+    /// Set the maximum amount of columns before the first match should be
+    /// printed in the preview.
+    ///
+    /// When this is not set (the default), the preview will print from the
+    /// beginning of the line.
+    pub fn max_columns_preview_before(
+        &mut self,
+        limit: Option<u64>,
+    ) -> &mut StandardBuilder {
+        self.config.max_columns_preview_before = limit;
+        self
+    }
+
     /// Set the maximum amount of matching lines that are printed.
     ///
     /// If multi line search is enabled and a match spans multiple lines, then
@@ -1360,6 +1375,13 @@ impl<'a, M: Matcher, W: WriteColor> StandardImpl<'a, M, W> {
     ) -> io::Result<()> {
         if self.config().max_columns_preview {
             let original = line;
+            if let Some(p) = self.config().max_columns_preview_before {
+                let start = matches[0].start().saturating_sub(p as usize);
+                if start != 0 {
+                    self.write(b"[... omitted start of long line] ")?;
+                    line = line.with_start(start);
+                }
+            }
             let end = bytes[line]
                 .grapheme_indices()
                 .map(|(_, end, _)| end)