go-common/vendor/github.com/mvdan/xurls/xurls.go
2019-04-22 02:59:20 +00:00

68 lines
2.6 KiB
Go

// Copyright (c) 2015, Daniel Martí <mvdan@mvdan.cc>
// See LICENSE for licensing information
// Package xurls extracts urls from plain text using regular expressions.
package xurls
import "regexp"
//go:generate go run generate/tldsgen/main.go
//go:generate go run generate/regexgen/main.go
const (
letter = `\p{L}`
mark = `\p{M}`
number = `\p{N}`
iriChar = letter + mark + number
currency = `\p{Sc}`
otherSymb = `\p{So}`
endChar = iriChar + `/\-+_&~*%=#` + currency + otherSymb
midChar = endChar + `@.,:;'?!|`
wellParen = `\([` + midChar + `]*(\([` + midChar + `]*\)[` + midChar + `]*)*\)`
wellBrack = `\[[` + midChar + `]*(\[[` + midChar + `]*\][` + midChar + `]*)*\]`
wellBrace = `\{[` + midChar + `]*(\{[` + midChar + `]*\}[` + midChar + `]*)*\}`
wellAll = wellParen + `|` + wellBrack + `|` + wellBrace
pathCont = `([` + midChar + `]*(` + wellAll + `|[` + endChar + `])+)+`
comScheme = `[a-zA-Z][a-zA-Z.\-+]*://`
scheme = `(` + comScheme + `|` + otherScheme + `)`
iri = `[` + iriChar + `]([` + iriChar + `\-]*[` + iriChar + `])?`
domain = `(` + iri + `\.)+`
octet = `(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])`
ipv4Addr = `\b` + octet + `\.` + octet + `\.` + octet + `\.` + octet + `\b`
ipv6Addr = `([0-9a-fA-F]{1,4}:([0-9a-fA-F]{1,4}:([0-9a-fA-F]{1,4}:([0-9a-fA-F]{1,4}:([0-9a-fA-F]{1,4}:[0-9a-fA-F]{0,4}|:[0-9a-fA-F]{1,4})?|(:[0-9a-fA-F]{1,4}){0,2})|(:[0-9a-fA-F]{1,4}){0,3})|(:[0-9a-fA-F]{1,4}){0,4})|:(:[0-9a-fA-F]{1,4}){0,5})((:[0-9a-fA-F]{1,4}){2}|:(25[0-5]|(2[0-4]|1[0-9]|[1-9])?[0-9])(\.(25[0-5]|(2[0-4]|1[0-9]|[1-9])?[0-9])){3})|(([0-9a-fA-F]{1,4}:){1,6}|:):[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){7}:`
ipAddr = `(` + ipv4Addr + `|` + ipv6Addr + `)`
site = domain + gtld
hostName = `(` + site + `|` + ipAddr + `)`
port = `(:[0-9]*)?`
path = `(/|/` + pathCont + `?|\b|$)`
webURL = hostName + port + path
strict = `(\b` + scheme + pathCont + `)`
relaxed = `(` + strict + `|` + webURL + `)`
)
var (
// Relaxed matches all the urls it can find.
Relaxed = regexp.MustCompile(relaxed)
// Strict only matches urls with a scheme to avoid false positives.
Strict = regexp.MustCompile(strict)
)
func init() {
Relaxed.Longest()
Strict.Longest()
}
// StrictMatchingScheme produces a regexp that matches urls like Strict but
// whose scheme matches the given regular expression.
func StrictMatchingScheme(exp string) (*regexp.Regexp, error) {
strictMatching := `(\b(?i)(` + exp + `)(?-i)` + pathCont + `)`
re, err := regexp.Compile(strictMatching)
if err != nil {
return nil, err
}
re.Longest()
return re, nil
}