README
¶
xstrings
Go package xstrings is a collection of string functions, which are widely used in other languages but absent in Go package strings.
All functions are well tested and carefully tuned for performance.
Propose a new function
Please review contributing guideline and create new issue to state why it should be included.
Install
Use go get to install this library.
go get github.com/huandu/xstrings
API document
See GoDoc for full document.
Function list
Go functions have a unique naming style. One, who has experience in other language but new in Go, may have difficulties to find out right string function to use.
Here is a list of functions in strings and xstrings with enough extra information about how to map these functions to their friends in other languages. Hope this list could be helpful for fresh gophers.
Package xstrings functions
Keep this table sorted by Function in ascending order.
| Function | Friends | # |
|---|---|---|
| Center | str.center in Python; String#center in Ruby |
#30 |
| Count | String#count in Ruby |
#16 |
| Delete | String#delete in Ruby |
#17 |
| ExpandTabs | str.expandtabs in Python |
#27 |
| FirstRuneToLower | lcfirst in PHP or Perl |
#15 |
| FirstRuneToUpper | String#capitalize in Ruby; ucfirst in PHP or Perl |
#15 |
| Insert | String#insert in Ruby |
#18 |
| LastPartition | str.rpartition in Python; String#rpartition in Ruby |
#19 |
| LeftJustify | str.ljust in Python; String#ljust in Ruby |
#28 |
| Len | mb_strlen in PHP |
#23 |
| Partition | str.partition in Python; String#partition in Ruby |
#10 |
| Reverse | String#reverse in Ruby; strrev in PHP; reverse in Perl |
#7 |
| RightJustify | str.rjust in Python; String#rjust in Ruby |
#29 |
| RuneWidth | - | #27 |
| Scrub | String#scrub in Ruby |
#20 |
| Shuffle | str_shuffle in PHP |
#13 |
| ShuffleSource | str_shuffle in PHP |
#13 |
| Slice | mb_substr in PHP |
#9 |
| Squeeze | String#squeeze in Ruby |
#11 |
| Successor | String#succ or String#next in Ruby |
#22 |
| SwapCase | str.swapcase in Python; String#swapcase in Ruby |
#12 |
| ToCamelCase | String#camelize in RoR |
#1 |
| ToKebab | - | #41 |
| ToSnakeCase | String#underscore in RoR |
#1 |
| Translate | str.translate in Python; String#tr in Ruby; strtr in PHP; tr/// in Perl |
#21 |
| Width | mb_strwidth in PHP |
#26 |
| WordCount | str_word_count in PHP |
#14 |
| WordSplit | - | #14 |
Package strings functions
Keep this table sorted by Function in ascending order.
| Function | Friends |
|---|---|
| Contains | String#include? in Ruby |
| ContainsAny | - |
| ContainsRune | - |
| Count | str.count in Python; substr_count in PHP |
| EqualFold | stricmp in PHP; String#casecmp in Ruby |
| Fields | str.split in Python; split in Perl; String#split in Ruby |
| FieldsFunc | - |
| HasPrefix | str.startswith in Python; String#start_with? in Ruby |
| HasSuffix | str.endswith in Python; String#end_with? in Ruby |
| Index | str.index in Python; String#index in Ruby; strpos in PHP; index in Perl |
| IndexAny | - |
| IndexByte | - |
| IndexFunc | - |
| IndexRune | - |
| Join | str.join in Python; Array#join in Ruby; implode in PHP; join in Perl |
| LastIndex | str.rindex in Python; String#rindex; strrpos in PHP; rindex in Perl |
| LastIndexAny | - |
| LastIndexFunc | - |
| Map | String#each_codepoint in Ruby |
| Repeat | operator * in Python and Ruby; str_repeat in PHP |
| Replace | str.replace in Python; String#sub in Ruby; str_replace in PHP |
| Split | str.split in Python; String#split in Ruby; explode in PHP; split in Perl |
| SplitAfter | - |
| SplitAfterN | - |
| SplitN | str.split in Python; String#split in Ruby; explode in PHP; split in Perl |
| Title | str.title in Python |
| ToLower | str.lower in Python; String#downcase in Ruby; strtolower in PHP; lc in Perl |
| ToLowerSpecial | - |
| ToTitle | - |
| ToTitleSpecial | - |
| ToUpper | str.upper in Python; String#upcase in Ruby; strtoupper in PHP; uc in Perl |
| ToUpperSpecial | - |
| Trim | str.strip in Python; String#strip in Ruby; trim in PHP |
| TrimFunc | - |
| TrimLeft | str.lstrip in Python; String#lstrip in Ruby; ltrim in PHP |
| TrimLeftFunc | - |
| TrimPrefix | - |
| TrimRight | str.rstrip in Python; String#rstrip in Ruby; rtrim in PHP |
| TrimRightFunc | - |
| TrimSpace | str.strip in Python; String#strip in Ruby; trim in PHP |
| TrimSuffix | String#chomp in Ruby; chomp in Perl |
License
This library is licensed under MIT license. See LICENSE for details.
Documentation
¶
Overview ¶
Package xstrings is to provide string algorithms which are useful but not included in `strings` package. See project home page for details. https://github.com/huandu/xstrings
Package xstrings assumes all strings are encoded in utf8.
Index ¶
- func Center(str string, length int, pad string) string
- func Count(str, pattern string) int
- func Delete(str, pattern string) string
- func ExpandTabs(str string, tabSize int) string
- func FirstRuneToLower(str string) string
- func FirstRuneToUpper(str string) string
- func Insert(dst, src string, index int) string
- func LastPartition(str, sep string) (head, match, tail string)
- func LeftJustify(str string, length int, pad string) string
- func Len(str string) int
- func Partition(str, sep string) (head, match, tail string)
- func Reverse(str string) string
- func RightJustify(str string, length int, pad string) string
- func RuneWidth(r rune) int
- func Scrub(str, repl string) string
- func Shuffle(str string) string
- func ShuffleSource(str string, src rand.Source) string
- func Slice(str string, start, end int) string
- func Squeeze(str, pattern string) string
- func Successor(str string) string
- func SwapCase(str string) string
- func ToCamelCase(str string) string
- func ToKebabCase(str string) string
- func ToSnakeCase(str string) string
- func Translate(str, from, to string) string
- func Width(str string) int
- func WordCount(str string) int
- func WordSplit(str string) []string
- type Translator
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Center ¶
Center returns a string with pad string at both side if str's rune length is smaller than length. If str's rune length is larger than length, str itself will be returned.
If pad is an empty string, str will be returned.
Samples:
Center("hello", 4, " ") => "hello"
Center("hello", 10, " ") => " hello "
Center("hello", 10, "123") => "12hello123"
func Count ¶
Count how many runes in str match the pattern. Pattern is defined in Translate function.
Samples:
Count("hello", "aeiou") => 3
Count("hello", "a-k") => 3
Count("hello", "^a-k") => 2
func Delete ¶
Delete runes in str matching the pattern. Pattern is defined in Translate function.
Samples:
Delete("hello", "aeiou") => "hll"
Delete("hello", "a-k") => "llo"
Delete("hello", "^a-k") => "he"
func ExpandTabs ¶
ExpandTabs can expand tabs ('\t') rune in str to one or more spaces dpending on current column and tabSize. The column number is reset to zero after each newline ('\n') occurring in the str.
ExpandTabs uses RuneWidth to decide rune's width. For example, CJK characters will be treated as two characters.
If tabSize <= 0, ExpandTabs panics with error.
Samples:
ExpandTabs("a\tbc\tdef\tghij\tk", 4) => "a bc def ghij k"
ExpandTabs("abcdefg\thij\nk\tl", 4) => "abcdefg hij\nk l"
ExpandTabs("z中\t文\tw", 4) => "z中 文 w"
func FirstRuneToLower ¶
FirstRuneToLower converts first rune to lower case if necessary.
func FirstRuneToUpper ¶
FirstRuneToUpper converts first rune to upper case if necessary.
func Insert ¶
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 LastPartition ¶
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 LeftJustify ¶
LeftJustify returns a string with pad string at right side if str's rune length is smaller than length. If str's rune length is larger than length, str itself will be returned.
If pad is an empty string, str will be returned.
Samples:
LeftJustify("hello", 4, " ") => "hello"
LeftJustify("hello", 10, " ") => "hello "
LeftJustify("hello", 10, "123") => "hello12312"
func Partition ¶
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 RightJustify ¶
RightJustify returns a string with pad string at left side if str's rune length is smaller than length. If str's rune length is larger than length, str itself will be returned.
If pad is an empty string, str will be returned.
Samples:
RightJustify("hello", 4, " ") => "hello"
RightJustify("hello", 10, " ") => " hello"
RightJustify("hello", 10, "123") => "12312hello"
func RuneWidth ¶
RuneWidth returns character width in monotype font. Multi-byte characters are usually twice the width of single byte characters.
Algorithm comes from `mb_strwidth` in PHP. http://php.net/manual/en/function.mb-strwidth.php
func Scrub ¶
Scrub scrubs invalid utf8 bytes with repl string. Adjacent invalid bytes are replaced only once.
func Shuffle ¶
Shuffle randomizes runes in a string and returns the result. It uses default random source in `math/rand`.
func ShuffleSource ¶
ShuffleSource randomizes runes in a string with given random source.
func Slice ¶
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 Squeeze ¶
Squeeze deletes adjacent repeated runes in str. If pattern is not empty, only runes matching the pattern will be squeezed.
Samples:
Squeeze("hello", "") => "helo"
Squeeze("hello", "m-z") => "hello"
Squeeze("hello world", " ") => "hello world"
func Successor ¶
Successor returns the successor to string.
If there is one alphanumeric rune is found in string, increase the rune by 1. If increment generates a "carry", the rune to the left of it is incremented. This process repeats until there is no carry, adding an additional rune if necessary.
If there is no alphanumeric rune, the rightmost rune will be increased by 1 regardless whether the result is a valid rune or not.
Only following characters are alphanumeric.
- a - z
- A - Z
- 0 - 9
Samples (borrowed from ruby's String#succ document):
"abcd" => "abce" "THX1138" => "THX1139" "<<koala>>" => "<<koalb>>" "1999zzz" => "2000aaa" "ZZZ9999" => "AAAA0000" "***" => "**+"
func ToCamelCase ¶
ToCamelCase can convert all lower case characters behind underscores to upper case character. Underscore character will be removed in result except following cases.
- More than 1 underscore. "a__b" => "A_B"
- At the beginning of string. "_a" => "_A"
- At the end of string. "ab_" => "Ab_"
func ToKebabCase ¶ added in v1.2.0
ToKebabCase can convert all upper case characters in a string to kebab case format.
Some samples.
"FirstName" => "first-name" "HTTPServer" => "http-server" "NoHTTPS" => "no-https" "GO_PATH" => "go-path" "GO PATH" => "go-path" // space is converted to '-'. "GO-PATH" => "go-path" // hyphen is converted to '-'. "HTTP2XX" => "http-2xx" // insert a '-' before a number and after an alphabet. "http2xx" => "http-2xx" "HTTP20xOK" => "http-20x-ok"
func ToSnakeCase ¶
ToSnakeCase can convert all upper case characters in a string to snake case format.
Some samples.
"FirstName" => "first_name" "HTTPServer" => "http_server" "NoHTTPS" => "no_https" "GO_PATH" => "go_path" "GO PATH" => "go_path" // space is converted to underscore. "GO-PATH" => "go_path" // hyphen is converted to underscore. "HTTP2XX" => "http_2xx" // insert an underscore before a number and after an alphabet. "http2xx" => "http_2xx" "HTTP20xOK" => "http_20x_ok"
func Translate ¶
Translate str with the characters defined in from replaced by characters defined in to.
From and to are patterns representing a set of characters. Pattern is defined as following.
- Special characters
- '-' means a range of runes, e.g.
- "a-z" means all characters from 'a' to 'z' inclusive;
- "z-a" means all characters from 'z' to 'a' inclusive.
- '^' as first character means a set of all runes excepted listed, e.g.
- "^a-z" means all characters except 'a' to 'z' inclusive.
- '\' escapes special characters.
- Normal character represents itself, e.g. "abc" is a set including 'a', 'b' and 'c'.
Translate will try to find a 1:1 mapping from from to to. If to is smaller than from, last rune in to will be used to map "out of range" characters in from.
Note that '^' only works in the from pattern. It will be considered as a normal character in the to pattern.
If the to pattern is an empty string, Translate works exactly the same as Delete.
Samples:
Translate("hello", "aeiou", "12345") => "h2ll4"
Translate("hello", "a-z", "A-Z") => "HELLO"
Translate("hello", "z-a", "a-z") => "svool"
Translate("hello", "aeiou", "*") => "h*ll*"
Translate("hello", "^l", "*") => "**ll*"
Translate("hello ^ world", `\^lo`, "*") => "he*** * w*r*d"
func Width ¶
Width returns string width in monotype font. Multi-byte characters are usually twice the width of single byte characters.
Algorithm comes from `mb_strwidth` in PHP. http://php.net/manual/en/function.mb-strwidth.php
func WordCount ¶
WordCount returns number of words in a string.
Word is defined as a locale dependent string containing alphabetic characters, which may also contain but not start with `'` and `-` characters.
Types ¶
type Translator ¶
type Translator struct {
// contains filtered or unexported fields
}
Translator can translate string with pre-compiled from and to patterns. If a from/to pattern pair needs to be used more than once, it's recommended to create a Translator and reuse it.
func NewTranslator ¶
func NewTranslator(from, to string) *Translator
NewTranslator creates new Translator through a from/to pattern pair.
func (*Translator) HasPattern ¶
func (tr *Translator) HasPattern() bool
HasPattern returns true if Translator has one pattern at least.
func (*Translator) Translate ¶
func (tr *Translator) Translate(str string) string
Translate str with a from/to pattern pair.
See comment in Translate function for usage and samples.
func (*Translator) TranslateRune ¶
func (tr *Translator) TranslateRune(r rune) (result rune, translated bool)
TranslateRune return translated rune and true if r matches the from pattern. If r doesn't match the pattern, original r is returned and translated is false.
Source Files