shannon-nu-cli 0.5.2

CLI-related functionality for Nushell
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137

use nu_ansi_term::{Color, Style};
use nu_color_config::get_shape_color;
use nu_protocol::Config;
use reedline::{Highlighter, StyledText};
use tree_sitter::{Node, Parser};

/// Syntax highlighter for bash using tree-sitter-bash.
/// Colors are read from nushell's color_config so bash highlighting
/// matches the user's nushell theme.
pub struct BashHighlighter {
    keyword: Style,
    command: Style,
    string: Style,
    number: Style,
    variable: Style,
    operator: Style,
    comment: Style,
    foreground: Style,
}

impl BashHighlighter {
    pub fn new(config: &Config) -> Self {
        BashHighlighter {
            keyword: get_shape_color("shape_keyword", config),
            command: get_shape_color("shape_external", config),
            string: get_shape_color("shape_string", config),
            number: get_shape_color("shape_int", config),
            variable: get_shape_color("shape_variable", config),
            operator: get_shape_color("shape_operator", config),
            comment: Style::new().fg(Color::DarkGray),
            foreground: Style::default(),
        }
    }

    fn bash_style(&self, node: &Node) -> Style {
        match node.kind() {
            "if" | "then" | "else" | "elif" | "fi" | "for" | "in" | "do" | "done" | "while"
            | "until" | "case" | "esac" | "function" | "export" | "declare" | "local"
            | "return" | "select" => self.keyword,

            "command_name" => self.command,

            "string" | "raw_string" | "heredoc_body" | "string_content" | "ansii_c_string" => {
                self.string
            }

            "number" => self.number,

            "variable_name" | "special_variable_name" => self.variable,
            "simple_expansion" | "expansion" => self.variable,
            "$" => self.variable,

            "|" | ">" | ">>" | "<" | "<<" | "&&" | "||" | ";" | ";;" | "&" => self.operator,
            "test_operator" => self.operator,

            "comment" => self.comment,

            _ => self.foreground,
        }
    }
}

impl Highlighter for BashHighlighter {
    fn highlight(&self, line: &str, _cursor: usize) -> StyledText {
        let mut styled = StyledText::new();

        if line.is_empty() {
            return styled;
        }

        let language: tree_sitter::Language = tree_sitter_bash::LANGUAGE.into();
        let mut parser = Parser::new();
        if parser.set_language(&language).is_err() {
            styled.push((self.foreground, line.to_string()));
            return styled;
        }

        let tree = match parser.parse(line, None) {
            Some(tree) => tree,
            None => {
                styled.push((self.foreground, line.to_string()));
                return styled;
            }
        };

        let mut segments: Vec<(usize, usize, Style)> = Vec::new();
        collect_leaf_styles(&tree.root_node(), self, &mut segments);

        segments.sort_by_key(|s| s.0);

        let mut pos = 0;
        for (start, end, style) in &segments {
            let start = *start;
            let end = (*end).min(line.len());
            if start > pos {
                styled.push((self.foreground, line[pos..start].to_string()));
            }
            if start >= pos && end > start {
                styled.push((*style, line[start..end].to_string()));
                pos = end;
            }
        }
        if pos < line.len() {
            styled.push((self.foreground, line[pos..].to_string()));
        }

        styled
    }
}

fn collect_leaf_styles(
    node: &Node,
    highlighter: &BashHighlighter,
    segments: &mut Vec<(usize, usize, Style)>,
) {
    if node.child_count() == 0 {
        let start = node.start_byte();
        let end = node.end_byte();
        let style = highlighter.bash_style(node);
        segments.push((start, end, style));
    } else {
        let parent_style = match node.kind() {
            "command_name" => Some(highlighter.command),
            "simple_expansion" | "expansion" => Some(highlighter.variable),
            "string" => Some(highlighter.string),
            _ => None,
        };

        if let Some(style) = parent_style {
            segments.push((node.start_byte(), node.end_byte(), style));
        } else {
            for child in node.children(&mut node.walk()) {
                collect_leaf_styles(&child, highlighter, segments);
            }
        }
    }
}