terraform/vendor/github.com/gosimple/slug/slug.go

127 lines
3.1 KiB
Go

// Copyright 2013 by Dobrosław Żybort. All rights reserved.
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
package slug
import (
"bytes"
"regexp"
"strings"
"github.com/rainycape/unidecode"
)
var (
// Custom substitution map
CustomSub map[string]string
// Custom rune substitution map
CustomRuneSub map[rune]string
// Maximum slug length. It's smart so it will cat slug after full word.
// By default slugs aren't shortened.
// If MaxLength is smaller than length of the first word, then returned
// slug will contain only substring from the first word truncated
// after MaxLength.
MaxLength int
regexpNonAuthorizedChars = regexp.MustCompile("[^a-z0-9-_]")
regexpMultipleDashes = regexp.MustCompile("-+")
)
//=============================================================================
// Make returns slug generated from provided string. Will use "en" as language
// substitution.
func Make(s string) (slug string) {
return MakeLang(s, "en")
}
// MakeLang returns slug generated from provided string and will use provided
// language for chars substitution.
func MakeLang(s string, lang string) (slug string) {
slug = strings.TrimSpace(s)
// Custom substitutions
// Always substitute runes first
slug = SubstituteRune(slug, CustomRuneSub)
slug = Substitute(slug, CustomSub)
// Process string with selected substitution language
switch lang {
case "de":
slug = SubstituteRune(slug, deSub)
case "en":
slug = SubstituteRune(slug, enSub)
case "pl":
slug = SubstituteRune(slug, plSub)
case "es":
slug = SubstituteRune(slug, esSub)
default: // fallback to "en" if lang not found
slug = SubstituteRune(slug, enSub)
}
// Process all non ASCII symbols
slug = unidecode.Unidecode(slug)
slug = strings.ToLower(slug)
// Process all remaining symbols
slug = regexpNonAuthorizedChars.ReplaceAllString(slug, "-")
slug = regexpMultipleDashes.ReplaceAllString(slug, "-")
slug = strings.Trim(slug, "-")
if MaxLength > 0 {
slug = smartTruncate(slug)
}
return slug
}
// Substitute returns string with superseded all substrings from
// provided substitution map.
func Substitute(s string, sub map[string]string) (buf string) {
buf = s
for key, val := range sub {
buf = strings.Replace(buf, key, val, -1)
}
return
}
// SubstituteRune substitutes string chars with provided rune
// substitution map.
func SubstituteRune(s string, sub map[rune]string) string {
var buf bytes.Buffer
for _, c := range s {
if d, ok := sub[c]; ok {
buf.WriteString(d)
} else {
buf.WriteRune(c)
}
}
return buf.String()
}
func smartTruncate(text string) string {
if len(text) < MaxLength {
return text
}
var truncated string
words := strings.SplitAfter(text, "-")
// If MaxLength is smaller than length of the first word return word
// truncated after MaxLength.
if len(words[0]) > MaxLength {
return words[0][:MaxLength]
}
for _, word := range words {
if len(truncated)+len(word)-1 <= MaxLength {
truncated = truncated + word
} else {
break
}
}
return strings.Trim(truncated, "-")
}