The long lost Emacs string manipulation library.
It's available on Melpa:
M-x package-install s
Or you can just dump s.el
in your load path somewhere.
- s-trim
(s)
- s-trim-left
(s)
- s-trim-right
(s)
- s-chomp
(s)
- s-collapse-whitespace
(s)
- s-word-wrap
(len s)
- s-center
(len s)
- s-pad-left
(len padding s)
- s-pad-right
(len padding s)
- s-truncate
(len s)
- s-left
(len s)
- s-right
(len s)
- s-chop-suffix
(suffix s)
- s-chop-suffixes
(suffixes s)
- s-chop-prefix
(prefix s)
- s-chop-prefixes
(prefixes s)
- s-shared-start
(s1 s2)
- s-shared-end
(s1 s2)
- s-lines
(s)
- s-match
(regexp s &optional start)
- s-match-strings-all
(regex string)
- s-matched-positions-all
(regexp string &optional subexp-depth)
- s-slice-at
(regexp s)
- s-split
(separator s &optional omit-nulls)
- s-split-up-to
(separator s n &optional omit-nulls)
- s-join
(separator strings)
- s-equals?
(s1 s2)
- s-less?
(s1 s2)
- s-matches?
(regexp s &optional start)
- s-blank?
(s)
- s-present?
(s)
- s-ends-with?
(suffix s &optional ignore-case)
- s-starts-with?
(prefix s &optional ignore-case)
- s-contains?
(needle s &optional ignore-case)
- s-lowercase?
(s)
- s-uppercase?
(s)
- s-mixedcase?
(s)
- s-capitalized?
(s)
- s-numeric?
(s)
- s-replace
(old new s)
- s-replace-all
(replacements s)
- s-downcase
(s)
- s-upcase
(s)
- s-capitalize
(s)
- s-titleize
(s)
- s-with
(s form &rest more)
- s-index-of
(needle s &optional ignore-case)
- s-reverse
(s)
- s-presence
(s)
- s-format
(template replacer &optional extra)
- s-lex-format
(format-str)
- s-count-matches
(regexp s &optional start end)
- s-wrap
(s prefix &optional suffix)
- s-split-words
(s)
- s-lower-camel-case
(s)
- s-upper-camel-case
(s)
- s-snake-case
(s)
- s-dashed-words
(s)
- s-capitalized-words
(s)
- s-titleized-words
(s)
- s-word-initials
(s)
Remove whitespace at the beginning and end of s
.
(s-trim "trim ") ;; => "trim"
(s-trim " this") ;; => "this"
(s-trim " only trims beg and end ") ;; => "only trims beg and end"
Remove whitespace at the beginning of s
.
(s-trim-left "trim ") ;; => "trim "
(s-trim-left " this") ;; => "this"
Remove whitespace at the end of s
.
(s-trim-right "trim ") ;; => "trim"
(s-trim-right " this") ;; => " this"
Remove one trailing \n
, \r
or \r\n
from s
.
(s-chomp "no newlines\n") ;; => "no newlines"
(s-chomp "no newlines\r\n") ;; => "no newlines"
(s-chomp "some newlines\n\n") ;; => "some newlines\n"
Convert all adjacent whitespace characters to a single space.
(s-collapse-whitespace "only one space please") ;; => "only one space please"
(s-collapse-whitespace "collapse \n all \t sorts of \r whitespace") ;; => "collapse all sorts of whitespace"
If s
is longer than len
, wrap the words with newlines.
(s-word-wrap 10 "This is too long") ;; => "This is\ntoo long"
(s-word-wrap 10 "This is way way too long") ;; => "This is\nway way\ntoo long"
(s-word-wrap 10 "It-wraps-words-but-does-not-break-them") ;; => "It-wraps-words-but-does-not-break-them"
If s
is shorter than len
, pad it with spaces so it is centered.
(s-center 5 "a") ;; => " a "
(s-center 5 "ab") ;; => " ab "
(s-center 1 "abc") ;; => "abc"
If s
is shorter than len
, pad it with padding
on the left.
(s-pad-left 3 "0" "3") ;; => "003"
(s-pad-left 3 "0" "23") ;; => "023"
(s-pad-left 3 "0" "1234") ;; => "1234"
If s
is shorter than len
, pad it with padding
on the right.
(s-pad-right 3 "." "3") ;; => "3.."
(s-pad-right 3 "." "23") ;; => "23."
(s-pad-right 3 "." "1234") ;; => "1234"
If s
is longer than len
, cut it down to len
- 3 and add ... at the end.
(s-truncate 6 "This is too long") ;; => "Thi..."
(s-truncate 16 "This is also too long") ;; => "This is also ..."
(s-truncate 16 "But this is not!") ;; => "But this is not!"
Returns up to the len
first chars of s
.
(s-left 3 "lib/file.js") ;; => "lib"
(s-left 3 "li") ;; => "li"
Returns up to the len
last chars of s
.
(s-right 3 "lib/file.js") ;; => ".js"
(s-right 3 "li") ;; => "li"
Remove suffix
if it is at end of s
.
(s-chop-suffix "-test.js" "penguin-test.js") ;; => "penguin"
(s-chop-suffix "\n" "no newlines\n") ;; => "no newlines"
(s-chop-suffix "\n" "some newlines\n\n") ;; => "some newlines\n"
Remove suffixes
one by one in order, if they are at the end of s
.
(s-chop-suffixes '("_test.js" "-test.js" "Test.js") "penguin-test.js") ;; => "penguin"
(s-chop-suffixes '("\r" "\n") "penguin\r\n") ;; => "penguin\r"
(s-chop-suffixes '("\n" "\r") "penguin\r\n") ;; => "penguin"
Remove prefix
if it is at the start of s
.
(s-chop-prefix "/tmp" "/tmp/file.js") ;; => "/file.js"
(s-chop-prefix "/tmp" "/tmp/tmp/file.js") ;; => "/tmp/file.js"
Remove prefixes
one by one in order, if they are at the start of s
.
(s-chop-prefixes '("/tmp" "/my") "/tmp/my/file.js") ;; => "/file.js"
(s-chop-prefixes '("/my" "/tmp") "/tmp/my/file.js") ;; => "/my/file.js"
Returns the longest prefix s1
and s2
have in common.
(s-shared-start "bar" "baz") ;; => "ba"
(s-shared-start "foobar" "foo") ;; => "foo"
(s-shared-start "bar" "foo") ;; => ""
Returns the longest suffix s1
and s2
have in common.
(s-shared-end "bar" "var") ;; => "ar"
(s-shared-end "foo" "foo") ;; => "foo"
(s-shared-end "bar" "foo") ;; => ""
Make a string of s
repeated num
times.
(s-repeat 10 " ") ;; => " "
(s-concat (s-repeat 8 "Na") " Batman!") ;; => "NaNaNaNaNaNaNaNa Batman!"
Join all the string arguments into one string.
(s-concat "abc" "def" "ghi") ;; => "abcdefghi"
Concatenate prefix
and s
.
(s-prepend "abc" "def") ;; => "abcdef"
Concatenate s
and suffix
.
(s-append "abc" "def") ;; => "defabc"
Splits s
into a list of strings on newline characters.
(s-lines "abc\ndef\nghi") ;; => '("abc" "def" "ghi")
(s-lines "abc\rdef\rghi") ;; => '("abc" "def" "ghi")
(s-lines "abc\r\ndef\r\nghi") ;; => '("abc" "def" "ghi")
When the given expression matches the string, this function returns a list of the whole matching string and a string for each matched subexpressions. If it did not match the returned value is an empty list (nil).
When start
is non-nil the search will start at that index.
(s-match "^def" "abcdefg") ;; => nil
(s-match "^abc" "abcdefg") ;; => '("abc")
(s-match "^/.*/\\([a-z]+\\)\\.\\([a-z]+\\)" "/some/weird/file.html") ;; => '("/some/weird/file.html" "file" "html")
Return a list of matches for regex
in string
.
Each element itself is a list of matches, as per
match-string
. Multiple matches at the same position will be
ignored after the first.
(s-match-strings-all "{\\([^}]+\\)}" "x is {x} and y is {y}") ;; => '(("{x}" "x") ("{y}" "y"))
(s-match-strings-all "ab." "abXabY") ;; => '(("abX") ("abY"))
(s-match-strings-all "\\<" "foo bar baz") ;; => '(("") ("") (""))
Return a list of matched positions for regexp
in string
.
subexp-depth
is 0 by default.
(s-matched-positions-all "l+" "{{Hello}} World, {{Emacs}}!" 0) ;; => '((4 . 6) (13 . 14))
(s-matched-positions-all "{{\\(.+?\\)}}" "{{Hello}} World, {{Emacs}}!" 0) ;; => '((0 . 9) (17 . 26))
(s-matched-positions-all "{{\\(.+?\\)}}" "{{Hello}} World, {{Emacs}}!" 1) ;; => '((2 . 7) (19 . 24))
Slices s
up at every index matching regexp
.
(s-slice-at "-" "abc") ;; => '("abc")
(s-slice-at "-" "abc-def") ;; => '("abc" "-def")
(s-slice-at "[.#]" "abc.def.ghi#id") ;; => '("abc" ".def" ".ghi" "#id")
Split s
into substrings bounded by matches for regexp separator
.
If omit-nulls
is non-nil, zero-length substrings are omitted.
This is a simple wrapper around the built-in split-string
.
(s-split "|" "a|bc|12|3") ;; => '("a" "bc" "12" "3")
(s-split ":" "a,c,d") ;; => '("a,c,d")
(s-split "\n" "z\nefg\n") ;; => '("z" "efg" "")
Split s
up to n
times into substrings bounded by matches for regexp separator
.
If omit-nulls
is non-nil, zero-length substrings are omitted.
See also s-split
.
(s-split-up-to "\\s-*-\\s-*" "Author - Track-number-one" 1) ;; => '("Author" "Track-number-one")
(s-split-up-to "\\s-*-\\s-*" "Author - Track-number-one" 2) ;; => '("Author" "Track" "number-one")
(s-split-up-to "|" "foo||bar|baz|qux" 3 t) ;; => '("foo" "bar" "baz|qux")
Join all the strings in strings
with separator
in between.
(s-join "+" '("abc" "def" "ghi")) ;; => "abc+def+ghi"
(s-join "\n" '("abc" "def" "ghi")) ;; => "abc\ndef\nghi"
Is s1
equal to s2
?
This is a simple wrapper around the built-in string-equal
.
(s-equals? "abc" "ABC") ;; => nil
(s-equals? "abc" "abc") ;; => t
Is s1
less than s2
?
This is a simple wrapper around the built-in string-lessp
.
(s-less? "abc" "abd") ;; => t
(s-less? "abd" "abc") ;; => nil
(s-less? "abc" "abc") ;; => nil
Does regexp
match s
?
If start
is non-nil the search starts at that index.
This is a simple wrapper around the built-in string-match-p
.
(s-matches? "^[0-9]+$" "123") ;; => t
(s-matches? "^[0-9]+$" "a123") ;; => nil
(s-matches? "1" "1a" 1) ;; => nil
Is s
nil or the empty string?
(s-blank? "") ;; => t
(s-blank? nil) ;; => t
(s-blank? " ") ;; => nil
Is s
anything but nil or the empty string?
(s-present? "") ;; => nil
(s-present? nil) ;; => nil
(s-present? " ") ;; => t
Does s
end with suffix
?
If ignore-case
is non-nil, the comparison is done without paying
attention to case differences.
Alias: s-suffix?
(s-ends-with? ".md" "readme.md") ;; => t
(s-ends-with? ".MD" "readme.md") ;; => nil
(s-ends-with? ".MD" "readme.md" t) ;; => t
Does s
start with prefix
?
If ignore-case
is non-nil, the comparison is done without paying
attention to case differences.
Alias: s-prefix?
. This is a simple wrapper around the built-in
string-prefix-p
.
(s-starts-with? "lib/" "lib/file.js") ;; => t
(s-starts-with? "LIB/" "lib/file.js") ;; => nil
(s-starts-with? "LIB/" "lib/file.js" t) ;; => t
Does s
contain needle
?
If ignore-case
is non-nil, the comparison is done without paying
attention to case differences.
(s-contains? "file" "lib/file.js") ;; => t
(s-contains? "nope" "lib/file.js") ;; => nil
(s-contains? "^a" "it's not ^a regexp") ;; => t
Are all the letters in s
in lower case?
(s-lowercase? "file") ;; => t
(s-lowercase? "File") ;; => nil
(s-lowercase? "filä") ;; => t
Are all the letters in s
in upper case?
(s-uppercase? "HULK SMASH") ;; => t
(s-uppercase? "Bruce no smash") ;; => nil
(s-uppercase? "FöB") ;; => nil
Are there both lower case and upper case letters in s
?
(s-mixedcase? "HULK SMASH") ;; => nil
(s-mixedcase? "Bruce no smash") ;; => t
(s-mixedcase? "BRÜCE") ;; => nil
In s
, is the first letter upper case, and all other letters lower case?
(s-capitalized? "Capitalized") ;; => t
(s-capitalized? "I am capitalized") ;; => t
(s-capitalized? "I Am Titleized") ;; => nil
Is s
a number?
(s-numeric? "123") ;; => t
(s-numeric? "onetwothree") ;; => nil
(s-numeric? "7a") ;; => nil
Replaces old
with new
in s
.
(s-replace "file" "nope" "lib/file.js") ;; => "lib/nope.js"
(s-replace "^a" "\\1" "it's not ^a regexp") ;; => "it's not \\1 regexp"
replacements
is a list of cons-cells. Each car
is replaced with cdr
in s
.
(s-replace-all '(("lib" . "test") ("file" . "file_test")) "lib/file.js") ;; => "test/file_test.js"
(s-replace-all '(("lib" . "test") ("test" . "lib")) "lib/test.js") ;; => "test/lib.js"
Convert s
to lower case.
This is a simple wrapper around the built-in downcase
.
(s-downcase "ABC") ;; => "abc"
Convert s
to upper case.
This is a simple wrapper around the built-in upcase
.
(s-upcase "abc") ;; => "ABC"
Convert the first word's first character to upper case and the rest to lower case in s
.
(s-capitalize "abc DEF") ;; => "Abc def"
(s-capitalize "abc.DEF") ;; => "Abc.def"
Convert each word's first character to upper case and the rest to lower case in s
.
This is a simple wrapper around the built-in capitalize
.
(s-titleize "abc DEF") ;; => "Abc Def"
(s-titleize "abc.DEF") ;; => "Abc.Def"
Threads s
through the forms. Inserts s
as the last item
in the first form, making a list of it if it is not a list
already. If there are more forms, inserts the first form as the
last item in second form, etc.
(s-with " hulk smash " s-trim s-upcase) ;; => "HULK SMASH"
(s-with "My car is a Toyota" (s-replace "car" "name") (s-replace "a Toyota" "Bond") (s-append ", James Bond")) ;; => "My name is Bond, James Bond"
(s-with "abc \ndef \nghi" s-lines (mapcar 's-trim) (s-join "-") s-reverse) ;; => "ihg-fed-cba"
Returns first index of needle
in s
, or nil.
If ignore-case
is non-nil, the comparison is done without paying
attention to case differences.
(s-index-of "abc" "abcdef") ;; => 0
(s-index-of "CDE" "abcdef" t) ;; => 2
(s-index-of "n.t" "not a regexp") ;; => nil
Return the reverse of s
.
(s-reverse "abc") ;; => "cba"
(s-reverse "ab xyz") ;; => "zyx ba"
(s-reverse "") ;; => ""
Return s
if it's s-present?
, otherwise return nil.
(s-presence nil) ;; => nil
(s-presence "") ;; => nil
(s-presence "foo") ;; => "foo"
Format template
with the function replacer
.
replacer
takes an argument of the format variable and optionally
an extra argument which is the extra
value from the call to
s-format
.
Several standard s-format
helper functions are recognized and
adapted for this:
(s-format "${name}" 'gethash hash-table)
(s-format "${name}" 'aget alist)
(s-format "$0" 'elt sequence)
The replacer
function may be used to do any other kind of
transformation.
(s-format "help ${name}! I'm ${malady}" 'aget '(("name" . "nic") ("malady" . "on fire"))) ;; => "help nic! I'm on fire"
(s-format "hello ${name}, nice day" (lambda (var-name) "nic")) ;; => "hello nic, nice day"
(s-format "hello $0, nice $1" 'elt '("nic" "day")) ;; => "hello nic, nice day"
s-format
with the current environment.
format-str
may use the s-format
variable reference to refer to
any variable:
(let ((x 1)) (s-lex-format "x is: ${x}"))
The values of the variables are interpolated with "%s" unless
the variable s-lex-value-as-lisp
is t
and then they are
interpolated with "%S".
(let ((x 1)) (s-lex-format "x is ${x}")) ;; => "x is 1"
(let ((str1 "this") (str2 "that")) (s-lex-format "${str1} and ${str2}")) ;; => "this and that"
(let ((foo "Hello\\nWorld")) (s-lex-format "${foo}")) ;; => "Hello\\nWorld"
Count occurrences of regexp
in `s'.
start
, inclusive, and end
, exclusive, delimit the part of s
to match.
(s-count-matches "a" "aba") ;; => 2
(s-count-matches "a" "aba" 0 2) ;; => 1
(s-count-matches "\\w\\{2\\}[0-9]+" "ab1bab2frobinator") ;; => 2
Wrap string s
with prefix
and optionally suffix
.
Return string s
with prefix
prepended. If suffix
is present, it
is appended, otherwise prefix
is used as both prefix and
suffix.
(s-wrap "foo" "\"") ;; => "\"foo\""
(s-wrap "foo" "(" ")") ;; => "(foo)"
(s-wrap "foo" "bar") ;; => "barfoobar"
Split s
into list of words.
(s-split-words "under_score") ;; => '("under" "score")
(s-split-words "some-dashed-words") ;; => '("some" "dashed" "words")
(s-split-words "evenCamelCase") ;; => '("even" "Camel" "Case")
Convert s
to lowerCamelCase.
(s-lower-camel-case "some words") ;; => "someWords"
(s-lower-camel-case "dashed-words") ;; => "dashedWords"
(s-lower-camel-case "under_scored_words") ;; => "underScoredWords"
Convert s
to UpperCamelCase.
(s-upper-camel-case "some words") ;; => "SomeWords"
(s-upper-camel-case "dashed-words") ;; => "DashedWords"
(s-upper-camel-case "under_scored_words") ;; => "UnderScoredWords"
Convert s
to snake_case.
(s-snake-case "some words") ;; => "some_words"
(s-snake-case "dashed-words") ;; => "dashed_words"
(s-snake-case "camelCasedWords") ;; => "camel_cased_words"
Convert s
to dashed-words.
(s-dashed-words "some words") ;; => "some-words"
(s-dashed-words "under_scored_words") ;; => "under-scored-words"
(s-dashed-words "camelCasedWords") ;; => "camel-cased-words"
Convert s
to Capitalized words.
(s-capitalized-words "some words") ;; => "Some words"
(s-capitalized-words "under_scored_words") ;; => "Under scored words"
(s-capitalized-words "camelCasedWords") ;; => "Camel cased words"
Convert s
to Titleized Words.
(s-titleized-words "some words") ;; => "Some Words"
(s-titleized-words "under_scored_words") ;; => "Under Scored Words"
(s-titleized-words "camelCasedWords") ;; => "Camel Cased Words"
Convert s
to its initials.
(s-word-initials "some words") ;; => "sw"
(s-word-initials "under_scored_words") ;; => "usw"
(s-word-initials "camelCasedWords") ;; => "cCW"
Imagine looking through the function list and seeing s-ends-with?
, but
s-starts-with?
is nowhere to be found. Why? Well, because Emacs already has
string-prefix-p
. Now you're starting out slightly confused, then have to go
somewhere else to dig for the command you were looking for.
The wrapping functions serve as both documentation for existing functions and makes for a consistent API.
-
inflections package provides functions for strings pluralization and singularization.
-
levenshtein package provides a function to calculate the Levenshtein distance between two strings.
-
string-utils is another general string manipulation library.
- Alias all functions ending in
?
(Tianxiang Xiong) - Add
s-blank-str?
(Aborn Jiang) - Several bugfixes
- Add
s-matched-positions-all
(ono hiroko)
- Add
s-wrap
(Johan Andersson) - Add
s-split-up-to
(Matus Goljer) - Fix
s-reverse
for Unicode combining characters. (Christopher Wellons)
- Add
s-count-matches
(Lars Andersen)
- Add
s-present?
ands-present?
(Johan Andersson) - Better handling of international characters
- Add
s-word-initials
(Sylvain Rousseau) - Better handling of camel cased strings (@Bruce-Connor)
- Add
s-pad-left
ands-pad-right
- Bugfixes for
s-format
(Nic Ferrier)
- Add
s-all-match-strings
(Geoff Gole) - Add
s-lex-format
(Nic Ferrier)
- Add
s-capitalized?
- Add
s-replace-all
- Add
s-slice-at
- Add
s-split
alias forsplit-string
(Rüdiger Sonderfeld) - Add
s-less?
predicate (Rüdiger Sonderfeld) - Add START parameter to
s-matches?
(Rüdiger Sonderfeld) - Bugfixes
- Add
s-numeric?
- Add
s-match
(Arthur Andersen) - Add
s-format
(Nic Ferrier) - Move .el files out of root to avoid problems with require.
-
Breaking change:
s-capitalize
now converts the first word's first character to upper case and the rest to lower case.s-titleize
works like the olds-capitalize
and capitalizes each word. (Johan Andersson) -
s-capitalized-words
ands-titleized-words
mirror this change.
- Arthur Andersen contributed
s-match
- Rolando contributed
s-shared-start
ands-shared-end
- Johan Andersson contributed
s-presence
,s-present?
and fixeds-titleize
vss-capitalize
- Nic Ferrier added
s-format
ands-lex-format
- Rüdiger Sonderfeld contributed
s-less?
,s-split
and several bugfixes. - Geoff Gole contributed
s-all-match-strings
- Sylvain Rousseau contributed
s-word-initials
- Lars Andersen contributed
s-count-matches
- ono hiroko contributed
s-matched-positions-all
Thanks!
Yes, please do. Pure functions in the string manipulation realm only,
please. There's a suite of tests in dev/examples.el
, so remember to add
tests for your function, or I might break it later.
You'll find the repo at:
https://github.com/magnars/s.el
Run the tests with
./run-tests.sh
Create the docs with
./create-docs.sh
I highly recommend that you install these as a pre-commit hook, so that the tests are always running and the docs are always in sync:
cp pre-commit.sh .git/hooks/pre-commit
Oh, and don't edit README.md
directly, it is auto-generated.
Change readme-template.md
or examples-to-docs.el
instead.
Copyright (C) 2012-2015 Magnar Sveen
Authors: Magnar Sveen magnars@gmail.com Keywords: strings
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.