show_highlight/
show_highlight.rs

1use std::env;
2use std::error::Error;
3use std::fs;
4
5use highlight_spans::Grammar;
6use render_ansi::{highlight_to_ansi_with_mode, ColorMode};
7use theme_engine::load_theme;
8
9/// Parses a grammar argument and returns a human-friendly error on failure.
10fn parse_grammar(input: &str) -> Result<Grammar, String> {
11    Grammar::from_name(input).ok_or_else(|| {
12        format!(
13            "unknown grammar '{}'; use one of: {}",
14            input,
15            Grammar::supported_names().join(", ")
16        )
17    })
18}
19
20/// Prints CLI usage for the `show_highlight` example.
21fn print_usage() {
22    eprintln!("Usage:");
23    eprintln!(
24        "  cargo run -p render-ansi --example show_highlight -- <source-file> [theme] [grammar] [--color-mode truecolor|ansi256|ansi16]"
25    );
26    eprintln!();
27    eprintln!("Examples:");
28    eprintln!("  cargo run -p render-ansi --example show_highlight -- sample.cls");
29    eprintln!(
30        "  cargo run -p render-ansi --example show_highlight -- sample.cls solarized-dark objectscript"
31    );
32    eprintln!(
33        "  cargo run -p render-ansi --example show_highlight -- sample.sql tokyonight-dark sql"
34    );
35    eprintln!(
36        "  cargo run -p render-ansi --example show_highlight -- sample.sql tokyonight-dark sql --color-mode ansi256"
37    );
38    eprintln!(
39        "  cargo run -p render-ansi --example show_highlight -- sample.sql tokyonight-dark sql --color-mode ansi16"
40    );
41}
42
43/// Parses a color mode argument and returns a human-friendly error on failure.
44fn parse_color_mode(input: &str) -> Result<ColorMode, String> {
45    ColorMode::from_name(input).ok_or_else(|| {
46        format!(
47            "unknown color mode '{}'; use one of: {}",
48            input,
49            ColorMode::supported_names().join(", ")
50        )
51    })
52}
53
54/// Loads a file, highlights it, and prints full-frame ANSI output.
55///
56/// # Errors
57///
58/// Returns an error when argument parsing, file IO, theme loading, or
59/// highlight/render execution fails.
60fn main() -> Result<(), Box<dyn Error>> {
61    let args: Vec<String> = env::args().collect();
62    if args.len() < 2 {
63        print_usage();
64        return Ok(());
65    }
66
67    let source_path = &args[1];
68    let theme_name = args.get(2).map(String::as_str).unwrap_or("tokyonight-dark");
69    let grammar_name = args.get(3).map(String::as_str).unwrap_or("objectscript");
70    let mut color_mode = ColorMode::TrueColor;
71
72    let mut i = 4usize;
73    while i < args.len() {
74        match args[i].as_str() {
75            "--color-mode" => {
76                i += 1;
77                let Some(value) = args.get(i) else {
78                    return Err("expected value after --color-mode".into());
79                };
80                color_mode =
81                    parse_color_mode(value).map_err(|msg| format!("invalid color mode: {msg}"))?;
82            }
83            flag => {
84                return Err(format!("unknown option '{flag}'").into());
85            }
86        }
87        i += 1;
88    }
89
90    let grammar = parse_grammar(grammar_name).map_err(|msg| format!("invalid grammar: {msg}"))?;
91    let source = fs::read(source_path)?;
92    let theme = load_theme(theme_name)?;
93
94    let rendered = highlight_to_ansi_with_mode(&source, grammar, &theme, color_mode)?;
95    println!("{rendered}");
96
97    Ok(())
98}
show_highlight/show_highlight.rs

show_highlight/
show_highlight.rs
