Highlight matching brackets / parentheses (#6655)

* [4325] - wip

* [4325] - hightlight only matched symbol

* [4325] - cleanup

* [4325] - match bracket while typing

* [4325] - fix clippy

* [4325] - add bracket highlight configuration

* [4325] - fix working with non-ascii

crates/nu-cli/src/syntax_highlight.rs

@@ -1,9 +1,10 @@
 use log::trace;
 use nu_ansi_term::Style;
-use nu_color_config::get_shape_color;
+use nu_color_config::{get_matching_brackets_style, get_shape_color};
 use nu_parser::{flatten_block, parse, FlatShape};
+use nu_protocol::ast::{Argument, Block, Expr, Expression};
 use nu_protocol::engine::{EngineState, StateWorkingSet};
-use nu_protocol::Config;
+use nu_protocol::{Config, Span};
 use reedline::{Highlighter, StyledText};
 
 pub struct NuHighlighter {
@@ -15,10 +16,12 @@ impl Highlighter for NuHighlighter {
     fn highlight(&self, line: &str, _cursor: usize) -> StyledText {
         trace!("highlighting: {}", line);
 
-        let (shapes, global_span_offset) = {
-            let mut working_set = StateWorkingSet::new(&self.engine_state);
+        let mut working_set = StateWorkingSet::new(&self.engine_state);
+        let block = {
             let (block, _) = parse(&mut working_set, None, line.as_bytes(), false, &[]);
-
+            block
+        };
+        let (shapes, global_span_offset) = {
             let shapes = flatten_block(&working_set, &block);
             (shapes, self.engine_state.next_span_start())
         };
@@ -26,6 +29,15 @@ impl Highlighter for NuHighlighter {
         let mut output = StyledText::default();
         let mut last_seen_span = global_span_offset;
 
+        let global_cursor_offset = _cursor + global_span_offset;
+        let matching_brackets_pos = find_matching_brackets(
+            line,
+            &working_set,
+            &block,
+            global_span_offset,
+            global_cursor_offset,
+        );
+
         for shape in &shapes {
             if shape.0.end <= last_seen_span
                 || last_seen_span < global_span_offset
@@ -44,166 +56,71 @@ impl Highlighter for NuHighlighter {
             let next_token = line
                 [(shape.0.start - global_span_offset)..(shape.0.end - global_span_offset)]
                 .to_string();
+
+            macro_rules! add_colored_token_with_bracket_highlight {
+                ($shape:expr, $span:expr, $text:expr) => {{
+                    let spans = split_span_by_highlight_positions(
+                        line,
+                        &$span,
+                        &matching_brackets_pos,
+                        global_span_offset,
+                    );
+                    spans.iter().for_each(|(part, highlight)| {
+                        let start = part.start - $span.start;
+                        let end = part.end - $span.start;
+                        let text = (&next_token[start..end]).to_string();
+                        let mut style = get_shape_color($shape.to_string(), &self.config);
+                        if *highlight {
+                            style = get_matching_brackets_style(style, &self.config);
+                        }
+                        output.push((style, text));
+                    });
+                }};
+            }
+
+            macro_rules! add_colored_token {
+                ($shape:expr, $text:expr) => {
+                    output.push((get_shape_color($shape.to_string(), &self.config), $text))
+                };
+            }
+
             match shape.1 {
-                FlatShape::Garbage => output.push((
-                    // nushell Garbage
-                    get_shape_color(shape.1.to_string(), &self.config),
-                    next_token,
-                )),
-                FlatShape::Nothing => output.push((
-                    // nushell Nothing
-                    get_shape_color(shape.1.to_string(), &self.config),
-                    next_token,
-                )),
-                FlatShape::Binary => {
-                    // nushell ?
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
-                }
-                FlatShape::Bool => {
-                    // nushell ?
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
-                }
-                FlatShape::Int => {
-                    // nushell Int
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
-                }
-                FlatShape::Float => {
-                    // nushell Decimal
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
-                }
-                FlatShape::Range => output.push((
-                    // nushell DotDot ?
-                    get_shape_color(shape.1.to_string(), &self.config),
-                    next_token,
-                )),
-                FlatShape::InternalCall => output.push((
-                    // nushell InternalCommand
-                    get_shape_color(shape.1.to_string(), &self.config),
-                    next_token,
-                )),
-                FlatShape::External => {
-                    // nushell ExternalCommand
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
-                }
-                FlatShape::ExternalArg => {
-                    // nushell ExternalWord
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
-                }
-                FlatShape::Literal => {
-                    // nushell ?
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
-                }
-                FlatShape::Operator => output.push((
-                    // nushell Operator
-                    get_shape_color(shape.1.to_string(), &self.config),
-                    next_token,
-                )),
-                FlatShape::Signature => output.push((
-                    // nushell ?
-                    get_shape_color(shape.1.to_string(), &self.config),
-                    next_token,
-                )),
-                FlatShape::String => {
-                    // nushell String
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
-                }
-                FlatShape::StringInterpolation => {
-                    // nushell ???
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
-                }
-                FlatShape::DateTime => {
-                    // nushell ???
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
-                }
+                FlatShape::Garbage => add_colored_token!(shape.1, next_token),
+                FlatShape::Nothing => add_colored_token!(shape.1, next_token),
+                FlatShape::Binary => add_colored_token!(shape.1, next_token),
+                FlatShape::Bool => add_colored_token!(shape.1, next_token),
+                FlatShape::Int => add_colored_token!(shape.1, next_token),
+                FlatShape::Float => add_colored_token!(shape.1, next_token),
+                FlatShape::Range => add_colored_token!(shape.1, next_token),
+                FlatShape::InternalCall => add_colored_token!(shape.1, next_token),
+                FlatShape::External => add_colored_token!(shape.1, next_token),
+                FlatShape::ExternalArg => add_colored_token!(shape.1, next_token),
+                FlatShape::Literal => add_colored_token!(shape.1, next_token),
+                FlatShape::Operator => add_colored_token!(shape.1, next_token),
+                FlatShape::Signature => add_colored_token!(shape.1, next_token),
+                FlatShape::String => add_colored_token!(shape.1, next_token),
+                FlatShape::StringInterpolation => add_colored_token!(shape.1, next_token),
+                FlatShape::DateTime => add_colored_token!(shape.1, next_token),
                 FlatShape::List => {
-                    // nushell ???
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
+                    add_colored_token_with_bracket_highlight!(shape.1, shape.0, next_token)
                 }
                 FlatShape::Table => {
-                    // nushell ???
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
+                    add_colored_token_with_bracket_highlight!(shape.1, shape.0, next_token)
                 }
                 FlatShape::Record => {
-                    // nushell ???
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
+                    add_colored_token_with_bracket_highlight!(shape.1, shape.0, next_token)
                 }
+
                 FlatShape::Block => {
-                    // nushell ???
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
+                    add_colored_token_with_bracket_highlight!(shape.1, shape.0, next_token)
                 }
-                FlatShape::Filepath => output.push((
-                    // nushell Path
-                    get_shape_color(shape.1.to_string(), &self.config),
-                    next_token,
-                )),
-                FlatShape::Directory => output.push((
-                    // nushell Directory
-                    get_shape_color(shape.1.to_string(), &self.config),
-                    next_token,
-                )),
-                FlatShape::GlobPattern => output.push((
-                    // nushell GlobPattern
-                    get_shape_color(shape.1.to_string(), &self.config),
-                    next_token,
-                )),
-                FlatShape::Variable => output.push((
-                    // nushell Variable
-                    get_shape_color(shape.1.to_string(), &self.config),
-                    next_token,
-                )),
-                FlatShape::Flag => {
-                    // nushell Flag
-                    output.push((
-                        get_shape_color(shape.1.to_string(), &self.config),
-                        next_token,
-                    ))
-                }
-                FlatShape::Custom(..) => output.push((
-                    get_shape_color(shape.1.to_string(), &self.config),
-                    next_token,
-                )),
+
+                FlatShape::Filepath => add_colored_token!(shape.1, next_token),
+                FlatShape::Directory => add_colored_token!(shape.1, next_token),
+                FlatShape::GlobPattern => add_colored_token!(shape.1, next_token),
+                FlatShape::Variable => add_colored_token!(shape.1, next_token),
+                FlatShape::Flag => add_colored_token!(shape.1, next_token),
+                FlatShape::Custom(..) => add_colored_token!(shape.1, next_token),
             }
             last_seen_span = shape.0.end;
         }
@@ -216,3 +133,296 @@ impl Highlighter for NuHighlighter {
         output
     }
 }
+
+fn split_span_by_highlight_positions(
+    line: &str,
+    span: &Span,
+    highlight_positions: &Vec<usize>,
+    global_span_offset: usize,
+) -> Vec<(Span, bool)> {
+    let mut start = span.start;
+    let mut result: Vec<(Span, bool)> = Vec::new();
+    for pos in highlight_positions {
+        if start <= *pos && pos < &span.end {
+            if start < *pos {
+                result.push((Span { start, end: *pos }, false));
+            }
+            let span_str = &line[pos - global_span_offset..span.end - global_span_offset];
+            let end = span_str
+                .chars()
+                .next()
+                .map(|c| pos + get_char_length(c))
+                .unwrap_or(pos + 1);
+            result.push((Span { start: *pos, end }, true));
+            start = end;
+        }
+    }
+    if start < span.end {
+        result.push((
+            Span {
+                start,
+                end: span.end,
+            },
+            false,
+        ));
+    }
+    result
+}
+
+fn find_matching_brackets(
+    line: &str,
+    working_set: &StateWorkingSet,
+    block: &Block,
+    global_span_offset: usize,
+    global_cursor_offset: usize,
+) -> Vec<usize> {
+    const BRACKETS: &str = "{}[]()";
+
+    // calculate first bracket position
+    let global_end_offset = line.len() + global_span_offset;
+    let global_bracket_pos =
+        if global_cursor_offset == global_end_offset && global_end_offset > global_span_offset {
+            // cursor is at the end of a non-empty string -- find block end at the previous position
+            if let Some(last_char) = line.chars().last() {
+                global_cursor_offset - get_char_length(last_char)
+            } else {
+                global_cursor_offset
+            }
+        } else {
+            // cursor is in the middle of a string -- find block end at the current position
+            global_cursor_offset
+        };
+
+    // check that position contains bracket
+    let match_idx = global_bracket_pos - global_span_offset;
+    if match_idx >= line.len()
+        || !BRACKETS.contains(get_char_at_index(line, match_idx).unwrap_or_default())
+    {
+        return Vec::new();
+    }
+
+    // find matching bracket by finding matching block end
+    let matching_block_end = find_matching_block_end_in_block(
+        line,
+        working_set,
+        block,
+        global_span_offset,
+        global_bracket_pos,
+    );
+    if let Some(pos) = matching_block_end {
+        let matching_idx = pos - global_span_offset;
+        if BRACKETS.contains(get_char_at_index(line, matching_idx).unwrap_or_default()) {
+            return if global_bracket_pos < pos {
+                vec![global_bracket_pos, pos]
+            } else {
+                vec![pos, global_bracket_pos]
+            };
+        }
+    }
+    Vec::new()
+}
+
+fn find_matching_block_end_in_block(
+    line: &str,
+    working_set: &StateWorkingSet,
+    block: &Block,
+    global_span_offset: usize,
+    global_cursor_offset: usize,
+) -> Option<usize> {
+    for p in &block.pipelines {
+        for e in &p.expressions {
+            if e.span.contains(global_cursor_offset) {
+                if let Some(pos) = find_matching_block_end_in_expr(
+                    line,
+                    working_set,
+                    e,
+                    global_span_offset,
+                    global_cursor_offset,
+                ) {
+                    return Some(pos);
+                }
+            }
+        }
+    }
+    None
+}
+
+fn find_matching_block_end_in_expr(
+    line: &str,
+    working_set: &StateWorkingSet,
+    expression: &Expression,
+    global_span_offset: usize,
+    global_cursor_offset: usize,
+) -> Option<usize> {
+    macro_rules! find_in_expr_or_continue {
+        ($inner_expr:ident) => {
+            if let Some(pos) = find_matching_block_end_in_expr(
+                line,
+                working_set,
+                $inner_expr,
+                global_span_offset,
+                global_cursor_offset,
+            ) {
+                return Some(pos);
+            }
+        };
+    }
+
+    if expression.span.contains(global_cursor_offset) {
+        let expr_first = expression.span.start;
+        let span_str = &line
+            [expression.span.start - global_span_offset..expression.span.end - global_span_offset];
+        let expr_last = span_str
+            .chars()
+            .last()
+            .map(|c| expression.span.end - get_char_length(c))
+            .unwrap_or(expression.span.start);
+
+        return match &expression.expr {
+            Expr::Bool(_) => None,
+            Expr::Int(_) => None,
+            Expr::Float(_) => None,
+            Expr::Binary(_) => None,
+            Expr::Range(..) => None,
+            Expr::Var(_) => None,
+            Expr::VarDecl(_) => None,
+            Expr::ExternalCall(..) => None,
+            Expr::Operator(_) => None,
+            Expr::UnaryNot(_) => None,
+            Expr::Keyword(..) => None,
+            Expr::ValueWithUnit(..) => None,
+            Expr::DateTime(_) => None,
+            Expr::Filepath(_) => None,
+            Expr::Directory(_) => None,
+            Expr::GlobPattern(_) => None,
+            Expr::String(_) => None,
+            Expr::CellPath(_) => None,
+            Expr::ImportPattern(_) => None,
+            Expr::Overlay(_) => None,
+            Expr::Signature(_) => None,
+            Expr::Nothing => None,
+            Expr::Garbage => None,
+
+            Expr::Table(hdr, rows) => {
+                if expr_last == global_cursor_offset {
+                    // cursor is at table end
+                    Some(expr_first)
+                } else if expr_first == global_cursor_offset {
+                    // cursor is at table start
+                    Some(expr_last)
+                } else {
+                    // cursor is inside table
+                    for inner_expr in hdr {
+                        find_in_expr_or_continue!(inner_expr);
+                    }
+                    for row in rows {
+                        for inner_expr in row {
+                            find_in_expr_or_continue!(inner_expr);
+                        }
+                    }
+                    None
+                }
+            }
+
+            Expr::Record(exprs) => {
+                if expr_last == global_cursor_offset {
+                    // cursor is at record end
+                    Some(expr_first)
+                } else if expr_first == global_cursor_offset {
+                    // cursor is at record start
+                    Some(expr_last)
+                } else {
+                    // cursor is inside record
+                    for (k, v) in exprs {
+                        find_in_expr_or_continue!(k);
+                        find_in_expr_or_continue!(v);
+                    }
+                    None
+                }
+            }
+
+            Expr::Call(call) => {
+                for arg in &call.arguments {
+                    let opt_expr = match arg {
+                        Argument::Named((_, _, opt_expr)) => opt_expr.as_ref(),
+                        Argument::Positional(inner_expr) => Some(inner_expr),
+                    };
+
+                    if let Some(inner_expr) = opt_expr {
+                        find_in_expr_or_continue!(inner_expr);
+                    }
+                }
+                None
+            }
+
+            Expr::FullCellPath(b) => find_matching_block_end_in_expr(
+                line,
+                working_set,
+                &b.head,
+                global_span_offset,
+                global_cursor_offset,
+            ),
+
+            Expr::BinaryOp(lhs, op, rhs) => {
+                find_in_expr_or_continue!(lhs);
+                find_in_expr_or_continue!(op);
+                find_in_expr_or_continue!(rhs);
+                None
+            }
+
+            Expr::Block(block_id)
+            | Expr::RowCondition(block_id)
+            | Expr::Subexpression(block_id) => {
+                if expr_last == global_cursor_offset {
+                    // cursor is at block end
+                    Some(expr_first)
+                } else if expr_first == global_cursor_offset {
+                    // cursor is at block start
+                    Some(expr_last)
+                } else {
+                    // cursor is inside block
+                    let nested_block = working_set.get_block(*block_id);
+                    find_matching_block_end_in_block(
+                        line,
+                        working_set,
+                        nested_block,
+                        global_span_offset,
+                        global_cursor_offset,
+                    )
+                }
+            }
+
+            Expr::StringInterpolation(inner_expr) => {
+                for inner_expr in inner_expr {
+                    find_in_expr_or_continue!(inner_expr);
+                }
+                None
+            }
+
+            Expr::List(inner_expr) => {
+                if expr_last == global_cursor_offset {
+                    // cursor is at list end
+                    Some(expr_first)
+                } else if expr_first == global_cursor_offset {
+                    // cursor is at list start
+                    Some(expr_last)
+                } else {
+                    // cursor is inside list
+                    for inner_expr in inner_expr {
+                        find_in_expr_or_continue!(inner_expr);
+                    }
+                    None
+                }
+            }
+        };
+    }
+    None
+}
+
+fn get_char_at_index(s: &str, index: usize) -> Option<char> {
+    s[index..].chars().next()
+}
+
+fn get_char_length(c: char) -> usize {
+    c.to_string().len()
+}

crates/nu-color-config/src/lib.rs

@@ -1,7 +1,9 @@
 mod color_config;
+mod matching_brackets_style;
 mod nu_style;
 mod shape_color;
 
 pub use color_config::*;
+pub use matching_brackets_style::*;
 pub use nu_style::*;
 pub use shape_color::*;

crates/nu-color-config/src/matching_brackets_style.rs

@@ -0,0 +1,30 @@
+use crate::color_config::lookup_ansi_color_style;
+use nu_ansi_term::Style;
+use nu_protocol::Config;
+
+pub fn get_matching_brackets_style(default_style: Style, conf: &Config) -> Style {
+    const MATCHING_BRACKETS_CONFIG_KEY: &str = "shape_matching_brackets";
+
+    match conf.color_config.get(MATCHING_BRACKETS_CONFIG_KEY) {
+        Some(int_color) => match int_color.as_string() {
+            Ok(int_color) => merge_styles(default_style, lookup_ansi_color_style(&int_color)),
+            Err(_) => default_style,
+        },
+        None => default_style,
+    }
+}
+
+fn merge_styles(base: Style, extra: Style) -> Style {
+    Style {
+        foreground: extra.foreground.or(base.foreground),
+        background: extra.background.or(base.background),
+        is_bold: extra.is_bold || base.is_bold,
+        is_dimmed: extra.is_dimmed || base.is_dimmed,
+        is_italic: extra.is_italic || base.is_italic,
+        is_underline: extra.is_underline || base.is_underline,
+        is_blink: extra.is_blink || base.is_blink,
+        is_reverse: extra.is_reverse || base.is_reverse,
+        is_hidden: extra.is_hidden || base.is_hidden,
+        is_strikethrough: extra.is_strikethrough || base.is_strikethrough,
+    }
+}

crates/nu-utils/src/sample_config/default_config.nu

@@ -179,6 +179,7 @@ let dark_theme = {
     shape_flag: blue_bold
     shape_custom: green
     shape_nothing: light_cyan
+    shape_matching_brackets: { attr: u }
 }
 
 let light_theme = {
@@ -231,6 +232,7 @@ let light_theme = {
     shape_flag: blue_bold
     shape_custom: green
     shape_nothing: light_cyan
+    shape_matching_brackets: { attr: u }
 }
 
 # External completer example