Highlight Rust Code From The Command Line With rust-analyzer

The rust-analyzer binary includes a few sub commands. One of them is "highlight" which produces an HTML output with highlighted code. For example, this:

Code

echo 'fn main() { println!("alfa"); }' \
| rust-analyzer highlight

Produces:

Code

<style>
body                { margin: 0; }
pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
.lifetime           { color: #DFAF8F; font-style: italic; }
.label              { color: #DFAF8F; font-style: italic; }
.comment            { color: #7F9F7F; }
.documentation      { color: #629755; }
.intra_doc_link     { font-style: italic; }
.injected           { opacity: 0.65 ; }
.struct, .enum      { color: #7CB8BB; }
.enum_variant       { color: #BDE0F3; }
.string_literal     { color: #CC9393; }
.field              { color: #94BFF3; }
.function           { color: #93E0E3; }
.function.unsafe    { color: #BC8383; }
.trait.unsafe       { color: #BC8383; }
.operator.unsafe    { color: #BC8383; }
.mutable.unsafe     { color: #BC8383; text-decoration: underline; }
.keyword.unsafe     { color: #BC8383; font-weight: bold; }
.macro.unsafe       { color: #BC8383; }
.parameter          { color: #94BFF3; }
.text               { color: #DCDCCC; }
.type               { color: #7CB8BB; }
.builtin_type       { color: #8CD0D3; }
.type_param         { color: #DFAF8F; }
.attribute          { color: #94BFF3; }
.numeric_literal    { color: #BFEBBF; }
.bool_literal       { color: #BFE6EB; }
.macro              { color: #94BFF3; }
.derive             { color: #94BFF3; font-style: italic; }
.module             { color: #AFD8AF; }
.value_param        { color: #DCDCCC; }
.variable           { color: #DCDCCC; }
.format_specifier   { color: #CC696B; }
.mutable            { text-decoration: underline; }
.escape_sequence    { color: #94BFF3; }
.keyword            { color: #F0DFAF; font-weight: bold; }
.control            { font-style: italic; }
.reference          { font-style: italic; font-weight: bold; }

.unresolved_reference { color: #FC5555; text-decoration: wavy underline; }
</style>
<pre><code><span class="keyword">fn</span> <span class="function declaration">main</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span> <span class="unresolved_reference">println</span><span class="macro_bang">!</span><span class="parenthesis">(</span><span class="string_literal">"alfa"</span><span class="parenthesis">)</span><span class="semicolon">;</span> <span class="brace">}</span>
</code></pre>