use std::env; use std::ffi::OsStr; use std::io::BufRead; use std::io; use std::path::Path; use syntect::easy::HighlightLines; use syntect::dumps::from_binary; use syntect::highlighting::ThemeSet; use syntect::parsing::SyntaxSet; use lazy_static::lazy_static; use syntect::html::{ append_highlighted_html_for_styled_line, start_highlighted_html_snippet, IncludeBackground, }; // Set up syntaxes as a lazy_static. Initialisation might not be // required in the case of Markdown rendering (if there's no code // blocks within the document). lazy_static! { static ref SYNTAXES: SyntaxSet = from_binary(include_bytes!(env!("BAT_SYNTAXES"))); } fn args_extension() -> Option { // The name of the file to be formatted is usually passed in as // the first argument and can be used to determine a syntax set. let args = env::args().collect::>(); if args.len() != 2 { return None } Path::new(&args[1]).extension() .and_then(OsStr::to_str) .map(|s| s.to_string()) } fn should_continue(res: &io::Result) -> bool { match *res { Ok(n) => n > 0, Err(_) => false, } } fn format_markdown() { unimplemented!("Not able to format Markdown just yet"); } fn format_code(extension: String) { let stdin = io::stdin(); let mut stdin = stdin.lock(); let mut linebuf = String::new(); // Get the first line, we might need it for syntax identification. let mut read_result = stdin.read_line(&mut linebuf); // Set up the highlighter let ts = ThemeSet::load_defaults(); let theme = &ts.themes["InspiredGitHub"]; let syntax = SYNTAXES.find_syntax_by_extension(&extension) .or_else(|| SYNTAXES.find_syntax_by_first_line(&linebuf)) .unwrap_or_else(|| SYNTAXES.find_syntax_plain_text()); // We're doing a completely different thing if the file is // Markdown, so lets do that thing. if syntax.name == "markdown" { } let mut hl = HighlightLines::new(syntax, theme); let (mut outbuf, bg) = start_highlighted_html_snippet(theme); // Rather than using the `lines` iterator, read each line manually // and maintain buffer state. // // This is done because the syntax highlighter requires trailing // newlines to be efficient, and those are stripped in the lines // iterator. while should_continue(&read_result) { let regions = hl.highlight(&linebuf, &SYNTAXES); append_highlighted_html_for_styled_line( ®ions[..], IncludeBackground::IfDifferent(bg), &mut outbuf, ); // immediately output the current state to avoid keeping // things in memory print!("{}", outbuf); // merry go round again linebuf.clear(); outbuf.clear(); read_result = stdin.read_line(&mut linebuf); } println!(""); } fn main() { let extension = args_extension() .expect("cheddar should be invoked with a filename!"); if extension == "md" { format_markdown(); } else { format_code(extension); } }