1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Basic html highlighting functionality
13 //! This module uses libsyntax's lexer to provide token-based highlighting for
14 //! the HTML documentation generated by rustdoc.
19 use syntax::parse::lexer;
21 use html::escape::Escape;
23 use t = syntax::parse::token;
25 /// Highlights some source code, returning the HTML output.
26 pub fn highlight(src: &str, class: Option<&str>, id: Option<&str>) -> String {
27 debug!("highlighting: ================\n{}\n==============", src);
28 let sess = parse::new_parse_sess();
29 let fm = parse::string_to_filemap(&sess,
31 "<stdin>".to_string());
33 let mut out = io::MemWriter::new();
35 lexer::StringReader::new(&sess.span_diagnostic, fm),
39 String::from_utf8_lossy(out.unwrap().as_slice()).into_string()
42 /// Exhausts the `lexer` writing the output into `out`.
44 /// The general structure for this method is to iterate over each token,
45 /// possibly giving it an HTML span with a class specifying what flavor of token
46 /// it's used. All source code emission is done as slices from the source map,
47 /// not from the tokens themselves, in order to stay true to the original
49 fn doit(sess: &parse::ParseSess, mut lexer: lexer::StringReader,
50 class: Option<&str>, id: Option<&str>,
51 out: &mut Writer) -> io::IoResult<()> {
52 use syntax::parse::lexer::Reader;
54 try!(write!(out, "<pre "));
56 Some(id) => try!(write!(out, "id='{}' ", id)),
59 try!(write!(out, "class='rust {}'>\n", class.unwrap_or("")));
60 let mut is_attribute = false;
61 let mut is_macro = false;
62 let mut is_macro_nonterminal = false;
64 let next = lexer.next_token();
66 let snip = |sp| sess.span_diagnostic.cm.span_to_snippet(sp).unwrap();
68 if next.tok == t::EOF { break }
70 let klass = match next.tok {
72 try!(write!(out, "{}", Escape(snip(next.sp).as_slice())));
76 try!(write!(out, "<span class='comment'>{}</span>",
77 Escape(snip(next.sp).as_slice())));
81 try!(write!(out, "{}", Escape(s.as_str())));
84 // If this '&' token is directly adjacent to another token, assume
85 // that it's the address-of operator instead of the and-operator.
86 // This allows us to give all pointers their own class (`Box` and
88 t::BINOP(t::AND) if lexer.peek().sp.lo == next.sp.hi => "kw-2",
89 t::AT | t::TILDE => "kw-2",
91 // consider this as part of a macro invocation if there was a
93 t::NOT if is_macro => { is_macro = false; "macro" }
96 t::EQ | t::LT | t::LE | t::EQEQ | t::NE | t::GE | t::GT |
97 t::ANDAND | t::OROR | t::NOT | t::BINOP(..) | t::RARROW |
98 t::BINOPEQ(..) | t::FAT_ARROW => "op",
100 // miscellaneous, no highlighting
101 t::DOT | t::DOTDOT | t::DOTDOTDOT | t::COMMA | t::SEMI |
102 t::COLON | t::MOD_SEP | t::LARROW | t::LPAREN |
103 t::RPAREN | t::LBRACKET | t::LBRACE | t::RBRACE | t::QUESTION => "",
105 if t::is_ident(&lexer.peek().tok) {
106 is_macro_nonterminal = true;
113 // This is the start of an attribute. We're going to want to
114 // continue highlighting it as an attribute until the ending ']' is
115 // seen, so skip out early. Down below we terminate the attribute
116 // span when we see the ']'.
119 try!(write!(out, r"<span class='attribute'>#"));
124 is_attribute = false;
125 try!(write!(out, "]</span>"));
133 t::LIT_BYTE(..) | t::LIT_BINARY(..) | t::LIT_BINARY_RAW(..) |
134 t::LIT_CHAR(..) | t::LIT_STR(..) | t::LIT_STR_RAW(..) => "string",
137 t::LIT_INTEGER(..) | t::LIT_FLOAT(..) => "number",
139 // keywords are also included in the identifier set
140 t::IDENT(ident, _is_mod_sep) => {
141 match t::get_ident(ident).get() {
142 "ref" | "mut" => "kw-2",
145 "false" | "true" => "boolval",
147 "Option" | "Result" => "prelude-ty",
148 "Some" | "None" | "Ok" | "Err" => "prelude-val",
150 _ if t::is_any_keyword(&next.tok) => "kw",
152 if is_macro_nonterminal {
153 is_macro_nonterminal = false;
155 } else if lexer.peek().tok == t::NOT {
165 t::LIFETIME(..) => "lifetime",
166 t::DOC_COMMENT(..) => "doccomment",
167 t::UNDERSCORE | t::EOF | t::INTERPOLATED(..) => "",
170 // as mentioned above, use the original source code instead of
171 // stringifying this token
172 let snip = sess.span_diagnostic.cm.span_to_snippet(next.sp).unwrap();
174 try!(write!(out, "{}", Escape(snip.as_slice())));
176 try!(write!(out, "<span class='{}'>{}</span>", klass,
177 Escape(snip.as_slice())));
181 write!(out, "</pre>\n")