fork fatih/camelcase

faith/camelcase has been archived and is no longer maintained.
The package is sufficiently small and self-contained enough to
maintain it in libpod.

Fixes: #4783
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

3 files changed, 168 insertions, 0 deletions

diff --git a/pkg/util/camelcase/LICENSE.md b/pkg/util/camelcase/LICENSE.md
new file mode 100644
index 000000000..aa4a536ca
--- /dev/null
+++ b/pkg/util/camelcase/LICENSE.md
@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 Fatih Arslan
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/pkg/util/camelcase/README.md b/pkg/util/camelcase/README.md
new file mode 100644
index 000000000..105a6ae33
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+++ b/pkg/util/camelcase/README.md
@@ -0,0 +1,58 @@
+# CamelCase [![GoDoc](http://img.shields.io/badge/go-documentation-blue.svg?style=flat-square)](http://godoc.org/github.com/fatih/camelcase) [![Build Status](http://img.shields.io/travis/fatih/camelcase.svg?style=flat-square)](https://travis-ci.org/fatih/camelcase)
+
+CamelCase is a Golang (Go) package to split the words of a camelcase type
+string into a slice of words. It can be used to convert a camelcase word (lower
+or upper case) into any type of word.
+
+## Splitting rules:
+
+1. If string is not valid UTF-8, return it without splitting as
+   single item array.
+2. Assign all unicode characters into one of 4 sets: lower case
+   letters, upper case letters, numbers, and all other characters.
+3. Iterate through characters of string, introducing splits
+   between adjacent characters that belong to different sets.
+4. Iterate through array of split strings, and if a given string
+   is upper case:
+   * if subsequent string is lower case:
+     * move last character of upper case string to beginning of
+       lower case string
+
+## Install
+
+```bash
+go get github.com/fatih/camelcase
+```
+
+## Usage and examples
+
+```go
+splitted := camelcase.Split("GolangPackage")
+
+fmt.Println(splitted[0], splitted[1]) // prints: "Golang", "Package"
+```
+
+Both lower camel case and upper camel case are supported. For more info please
+check: [http://en.wikipedia.org/wiki/CamelCase](http://en.wikipedia.org/wiki/CamelCase)
+
+Below are some example cases:
+
+```
+"" =>                     []
+"lowercase" =>            ["lowercase"]
+"Class" =>                ["Class"]
+"MyClass" =>              ["My", "Class"]
+"MyC" =>                  ["My", "C"]
+"HTML" =>                 ["HTML"]
+"PDFLoader" =>            ["PDF", "Loader"]
+"AString" =>              ["A", "String"]
+"SimpleXMLParser" =>      ["Simple", "XML", "Parser"]
+"vimRPCPlugin" =>         ["vim", "RPC", "Plugin"]
+"GL11Version" =>          ["GL", "11", "Version"]
+"99Bottles" =>            ["99", "Bottles"]
+"May5" =>                 ["May", "5"]
+"BFG9000" =>              ["BFG", "9000"]
+"BöseÜberraschung" =>     ["Böse", "Überraschung"]
+"Two  spaces" =>          ["Two", "  ", "spaces"]
+"BadUTF8\xe2\xe2\xa1" =>  ["BadUTF8\xe2\xe2\xa1"]
+```
diff --git a/pkg/util/camelcase/camelcase.go b/pkg/util/camelcase/camelcase.go
new file mode 100644
index 000000000..02160c9a4
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+++ b/pkg/util/camelcase/camelcase.go
@@ -0,0 +1,90 @@
+// Package camelcase is a micro package to split the words of a camelcase type
+// string into a slice of words.
+package camelcase
+
+import (
+	"unicode"
+	"unicode/utf8"
+)
+
+// Split splits the camelcase word and returns a list of words. It also
+// supports digits. Both lower camel case and upper camel case are supported.
+// For more info please check: http://en.wikipedia.org/wiki/CamelCase
+//
+// Examples
+//
+//   "" =>                     [""]
+//   "lowercase" =>            ["lowercase"]
+//   "Class" =>                ["Class"]
+//   "MyClass" =>              ["My", "Class"]
+//   "MyC" =>                  ["My", "C"]
+//   "HTML" =>                 ["HTML"]
+//   "PDFLoader" =>            ["PDF", "Loader"]
+//   "AString" =>              ["A", "String"]
+//   "SimpleXMLParser" =>      ["Simple", "XML", "Parser"]
+//   "vimRPCPlugin" =>         ["vim", "RPC", "Plugin"]
+//   "GL11Version" =>          ["GL", "11", "Version"]
+//   "99Bottles" =>            ["99", "Bottles"]
+//   "May5" =>                 ["May", "5"]
+//   "BFG9000" =>              ["BFG", "9000"]
+//   "BöseÜberraschung" =>     ["Böse", "Überraschung"]
+//   "Two  spaces" =>          ["Two", "  ", "spaces"]
+//   "BadUTF8\xe2\xe2\xa1" =>  ["BadUTF8\xe2\xe2\xa1"]
+//
+// Splitting rules
+//
+//  1) If string is not valid UTF-8, return it without splitting as
+//     single item array.
+//  2) Assign all unicode characters into one of 4 sets: lower case
+//     letters, upper case letters, numbers, and all other characters.
+//  3) Iterate through characters of string, introducing splits
+//     between adjacent characters that belong to different sets.
+//  4) Iterate through array of split strings, and if a given string
+//     is upper case:
+//       if subsequent string is lower case:
+//         move last character of upper case string to beginning of
+//         lower case string
+func Split(src string) (entries []string) {
+	// don't split invalid utf8
+	if !utf8.ValidString(src) {
+		return []string{src}
+	}
+	entries = []string{}
+	var runes [][]rune
+	lastClass := 0
+	class := 0
+	// split into fields based on class of unicode character
+	for _, r := range src {
+		switch true {
+		case unicode.IsLower(r):
+			class = 1
+		case unicode.IsUpper(r):
+			class = 2
+		case unicode.IsDigit(r):
+			class = 3
+		default:
+			class = 4
+		}
+		if class == lastClass {
+			runes[len(runes)-1] = append(runes[len(runes)-1], r)
+		} else {
+			runes = append(runes, []rune{r})
+		}
+		lastClass = class
+	}
+	// handle upper case -> lower case sequences, e.g.
+	// "PDFL", "oader" -> "PDF", "Loader"
+	for i := 0; i < len(runes)-1; i++ {
+		if unicode.IsUpper(runes[i][0]) && unicode.IsLower(runes[i+1][0]) {
+			runes[i+1] = append([]rune{runes[i][len(runes[i])-1]}, runes[i+1]...)
+			runes[i] = runes[i][:len(runes[i])-1]
+		}
+	}
+	// construct []string from results
+	for _, s := range runes {
+		if len(s) > 0 {
+			entries = append(entries, string(s))
+		}
+	}
+	return
+}