highlight is a golang library for highlighting code syntax of different programming and markup languages inside HTML documents.

Install

Supported Go versions:

• 1.11
• 1.17
• 1.18

Add to go.mod file:

require github.com/lcomrade/highlight v1

How it works?

The <span> tag is used to highlight syntax when converting to HTML. This tag does not do anything on its own, but you can assign different properties to it in CSS. Including color and font.

All extraneous HTML tags will be protected.

Before highlighting:

User-agent: * # comment
Disallow: /faq

# comment 1
# comment 2

Allow: /
Crawl-delay: 10
Sitemap: https://example.org/sitemap.xml
Host: https://mirror.example.org

After highlighting:

<span class='code-keyword'>User-agent:</span> * <span class='code-c'># comment</span>
<span class='code-keyword'>Disallow:</span> /faq

<span class='code-comment'># comment 1</span>
<span class='code-comment'># comment 2</span>

<span class='code-keyword'>Allow:</span> /
<span class='code-keyword'>Crawl-delay:</span> 10
<span class='code-keyword'>Sitemap:</span> https://example.org/sitemap.xml
<span class='code-keyword'>Host:</span> https://mirror.example.org

Supported languages

• C
• Dockerfile
• Golang
• go.mod
• INI
• Java
• JSON
• Python
• robots.txt
• SQL

Code example

package main

import (
	"fmt"
	"github.com/lcomrade/highlight"
)

func main() {
	// Code written in the C language
	myCode := `
#include <stdio.h>

// Comment

int main() {
	printf("Hello, world!");

	return 0;
}
`

	// Highlight
	fmt.Println(highlight.C(myCode))
}

Read more in the documentation

CSS classes

Example of a CSS file:

.code-operator, .code-keyword, .code-build-in-func, .code-key {
	color: Firebrick;
}

.code-var-type, .code-build-in-var {
	color: RoyalBlue;
}

.code-brackets {
	color: ForestGreen;
}

.code-comment {
	color: DimGray;
}

Documentation

• Offline documentation: go doc -all github.com/lcomrade/highlight
• Online documentation
• Changelog