grokify/mogo

package markdown

import (
    "fmt"
    "regexp"
    "strings"
)

// BoldText bodifies the identified text. It looks for start of words
// using a word boundary and will arbirarily end to match words with
// different suffixes.
func BoldText(haystack, needle string) string {
    output := haystack
    if len(needle) == 0 {
        return "**" + haystack + "**"
    }
    return regexp.MustCompile(`(?i)\b(`+regexp.QuoteMeta(needle)+`)`).ReplaceAllString(output, "**$1**")
}

func URLToMarkdownLinkHostname(url string) string {
    rx := regexp.MustCompile(`(?i)^https?://([^/]+)(/[^/])`)
    m := rx.FindStringSubmatch(url)
    if len(m) > 1 {
        suffix := ""
        if len(m) > 2 {
            suffix = "..."
        }
        return fmt.Sprintf("[%v%v](%v)", m[1], suffix, url)
    }
    return url
}

// Linkify constructs a link from url and text inputs.
// This function does not handle escaping so it should
// be done before hand, e.g. using `\[` instead of `[`
// by itself in the `text`.
func Linkify(url, text string) string {
    url = strings.TrimSpace(url)
    if len(url) == 0 {
        return text
    }
    if len(text) == 0 {
        return "[" + url + "](" + url + ")"
    }
    return "[" + text + "](" + url + ")"
}

var rxParseLink = regexp.MustCompile(`\[(.*)\]\((.*)\)`)

// ParseLink returns text and url.
func ParseLink(s string) (string, string) {
    m := rxParseLink.FindStringSubmatch(s)
    if len(m) > 0 {
        return m[1], m[2]
    }
    return s, ""
}