diff options
Diffstat (limited to 'vendor/github.com/huandu/xstrings/manipulate.go')
-rw-r--r-- | vendor/github.com/huandu/xstrings/manipulate.go | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/vendor/github.com/huandu/xstrings/manipulate.go b/vendor/github.com/huandu/xstrings/manipulate.go new file mode 100644 index 0000000000..0eefb43ed7 --- /dev/null +++ b/vendor/github.com/huandu/xstrings/manipulate.go @@ -0,0 +1,217 @@ +// Copyright 2015 Huan Du. All rights reserved. +// Licensed under the MIT license that can be found in the LICENSE file. + +package xstrings + +import ( + "bytes" + "strings" + "unicode/utf8" +) + +// Reverse a utf8 encoded string. +func Reverse(str string) string { + var size int + + tail := len(str) + buf := make([]byte, tail) + s := buf + + for len(str) > 0 { + _, size = utf8.DecodeRuneInString(str) + tail -= size + s = append(s[:tail], []byte(str[:size])...) + str = str[size:] + } + + return string(buf) +} + +// Slice a string by rune. +// +// Start must satisfy 0 <= start <= rune length. +// +// End can be positive, zero or negative. +// If end >= 0, start and end must satisfy start <= end <= rune length. +// If end < 0, it means slice to the end of string. +// +// Otherwise, Slice will panic as out of range. +func Slice(str string, start, end int) string { + var size, startPos, endPos int + + origin := str + + if start < 0 || end > len(str) || (end >= 0 && start > end) { + panic("out of range") + } + + if end >= 0 { + end -= start + } + + for start > 0 && len(str) > 0 { + _, size = utf8.DecodeRuneInString(str) + start-- + startPos += size + str = str[size:] + } + + if end < 0 { + return origin[startPos:] + } + + endPos = startPos + + for end > 0 && len(str) > 0 { + _, size = utf8.DecodeRuneInString(str) + end-- + endPos += size + str = str[size:] + } + + if len(str) == 0 && (start > 0 || end > 0) { + panic("out of range") + } + + return origin[startPos:endPos] +} + +// Partition splits a string by sep into three parts. +// The return value is a slice of strings with head, match and tail. +// +// If str contains sep, for example "hello" and "l", Partition returns +// "he", "l", "lo" +// +// If str doesn't contain sep, for example "hello" and "x", Partition returns +// "hello", "", "" +func Partition(str, sep string) (head, match, tail string) { + index := strings.Index(str, sep) + + if index == -1 { + head = str + return + } + + head = str[:index] + match = str[index : index+len(sep)] + tail = str[index+len(sep):] + return +} + +// LastPartition splits a string by last instance of sep into three parts. +// The return value is a slice of strings with head, match and tail. +// +// If str contains sep, for example "hello" and "l", LastPartition returns +// "hel", "l", "o" +// +// If str doesn't contain sep, for example "hello" and "x", LastPartition returns +// "", "", "hello" +func LastPartition(str, sep string) (head, match, tail string) { + index := strings.LastIndex(str, sep) + + if index == -1 { + tail = str + return + } + + head = str[:index] + match = str[index : index+len(sep)] + tail = str[index+len(sep):] + return +} + +// Insert src into dst at given rune index. +// Index is counted by runes instead of bytes. +// +// If index is out of range of dst, panic with out of range. +func Insert(dst, src string, index int) string { + return Slice(dst, 0, index) + src + Slice(dst, index, -1) +} + +// Scrub scrubs invalid utf8 bytes with repl string. +// Adjacent invalid bytes are replaced only once. +func Scrub(str, repl string) string { + var buf *bytes.Buffer + var r rune + var size, pos int + var hasError bool + + origin := str + + for len(str) > 0 { + r, size = utf8.DecodeRuneInString(str) + + if r == utf8.RuneError { + if !hasError { + if buf == nil { + buf = &bytes.Buffer{} + } + + buf.WriteString(origin[:pos]) + hasError = true + } + } else if hasError { + hasError = false + buf.WriteString(repl) + + origin = origin[pos:] + pos = 0 + } + + pos += size + str = str[size:] + } + + if buf != nil { + buf.WriteString(origin) + return buf.String() + } + + // No invalid byte. + return origin +} + +// WordSplit splits a string into words. Returns a slice of words. +// If there is no word in a string, return nil. +// +// Word is defined as a locale dependent string containing alphabetic characters, +// which may also contain but not start with `'` and `-` characters. +func WordSplit(str string) []string { + var word string + var words []string + var r rune + var size, pos int + + inWord := false + + for len(str) > 0 { + r, size = utf8.DecodeRuneInString(str) + + switch { + case isAlphabet(r): + if !inWord { + inWord = true + word = str + pos = 0 + } + + case inWord && (r == '\'' || r == '-'): + // Still in word. + + default: + if inWord { + inWord = false + words = append(words, word[:pos]) + } + } + + pos += size + str = str[size:] + } + + if inWord { + words = append(words, word[:pos]) + } + + return words +} |