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This is the str Reference Manual, version 0.17, generated automatically by Declt version 3.0 "Montgomery Scott" on Tue Apr 28 11:21:36 2020 GMT+0.
| • Introduction | What str is all about | |
| • Systems | The systems documentation | |
| • Files | The files documentation | |
| • Packages | The packages documentation | |
| • Definitions | The symbols documentation | |
| • Indexes | Concepts, functions, variables and data types |
(ql:quickload "str")
also on Ultralisp.
Why ?
modernity, simplicity and discoverability:
(str:trim s) instead of (string-trim '(#\Space #\Newline #\Backspace #\Tab #\Linefeed #\Page #\Return #\Rubout) s)),
or str:concat strings instead of an unusual format construct; one discoverable library instead of many;consistence and composability, where s is always the last argument, which makes it
easier to feed pipes and arrows.
fixing built-in surprises: (string-downcase nil) => "nil" the string, whereas (str:downcase nil) => nil.
The only dependency is cl-ppcre.
Table of Contents
Install with Quicklisp:
(ql:quickload :str)
Check its version:
(str:version)
To get a newer version, you need to update the Quicklisp dist (think of QL as Debian's apt rather than pip/npm/etc):
(ql:update-dist "quicklisp")
Don't have a full Common Lisp development environment yet ? Get Portacle, a portable and multiplatform development environment shipping Emacs, Quicklisp, SBCL and Git. See also editor support (Vim, Lem, Atom, Eclipse,…).
Some parameters are common to various functions and often used:
:ignore-case and :omit-nulls.
Consequently we can also manage them with global parameters:
(let ((str:*ignore-case* t))
(str:ends-with? "BAR" "foobar"))
is equivalent to
(str:ends-with? "BAR" "foobar" :ignore-case t)
(s)Remove whitespaces at the beginning and end of s.
(trim " rst ") ;; => "rst"
Also trim-left and trim-right.
Uses the built-in
string-trim
where whitespaces are '(#\Space #\Newline #\Backspace #\Tab #\Linefeed #\Page #\Return #\Rubout).
(s)Ensure there is only one space character between words. Remove newlines.
(collapse-whitespaces "foo bar
baz")
;; "foo bar baz"
;;T
(separator list-of-strings)Join strings in list list-of-strings with separator (either a string or a char) in between.
(join " " '("foo" "bar" "baz")) ;; => "foo bar baz"
(join #\Space '("foo" "bar" "baz")) ;; => "foo bar baz"
It uses the { iteration format directive. See also this quick reference:
(format nil "~{~a+~}" '(:a :b :c)) ;; the + is the separator
;; => "A+B+C+"
We use the caret directive ("escape upward") to not print the separator in the end:
(format nil "~{~a~^+~}" '(:a :b :c))
;; => "A+B+C"
(&rest strings)Join strings into one.
(concat "f" "o" "o") ;; => "foo"
Simple call of the built-in concatenate.
We actually also have uiop:strcat.
(string/char index s)Insert the given string (or character) at the index index into s and return a
new string.
If index is out of bounds, just return s.
(str:insert "l" 2 "helo") ; => "hello"
(str:insert "o" 99 "hell") : => "hell"
(count s)Make a string of s repeated count times.
(repeat 3 "foo") ;; => "foofoofoo"
(items s)Respectively prepend or append s to the front of each item.
(len s &key (pad-side :right) (pad-char #\Space)), pad-left, pad-right, pad-center (new in 0.16, 2019/12)Fill s with characters until it is of the given length. By default,
add spaces on the right:
(str:pad 10 "foo")
"foo "
pad-side: one of :right (the default), :left or :center. See *pad-side*.pad-char: the padding character (or string of one character). Defaults to a space. See *pad-char*.(str:pad 10 "foo" :pad-side :center :pad-char "+")
"+++foo++++"
If the given length is smaller than the length o s, return s.
Filling with spaces can easily be done with format:
(format nil "~va" len s) ;; => "foo "
(format nil "~v@a" 10 "foo") ;; => " foo" (with @)
(start end s)Return the substring of s from start to end.
It uses subseq with differences:
start and end can be lower than 0 or bigger than the length of s.end can be nil or t to denote the end of the string.Examples:
(is "abcd" (substring 0 t "abcd") "t denotes the end of the string")
(is "abcd" (substring 0 nil "abcd") "nil too")
(is "abcd" (substring 0 100 "abcd") "end can be too large")
(is "abc" (substring 0 -1 "abcd") "end can be negative. Counts from the end.")
(is "" (substring 0 -100 "abcd") "end can be negative and too low")
(is "" (substring 100 1 "abcd") "start can be too big")
(is "abcd" (substring -100 4 "abcd") "start can also be too low")
(is "" (substring 2 1 "abcd") "start is bigger than end")
(s)Return the first letter of s.
Examples:
(s-first "foobar") ;; => "f"
(s-first "") ;; => ""
(s)Return the last letter of s.
(s)Return the rest substring of s.
Examples:
(s-rest "foobar") ;; => "oobar"
(s-rest "") ;; => ""
(n s)Return the nth letter of s.
Examples:
(s-nth 3 "foobar") ;; => "b"
(s-nth 3 "") ;; => ""
You could also use
(elt "test" 1)
;; => #\e
(string (elt "test" 1))
;; => "e"
(len s &key ellipsis)If s is longer than len, truncate it and add an ellipsis at the
end (... by default). s is cut down to len minus the length of
the ellipsis (3 by default).
Optionally, give an :ellipsis keyword argument. Also set it globally
with *ellipsis*.
(shorten 8 "hello world")
;; => "hello..."
(shorten 3 "hello world")
;; => "..."
(shorten 8 "hello world" :ellipsis "-")
;; => "hello w-"
(let ((*ellipsis* "-"))
(shorten 8 "hello world"))
;; => "hello w-"
(s)Return list of words, which were delimited by whitespace.
(strings)Join the list of strings with a whitespace.
(s &key omit-nulls)Split string by newline character and return list of lines.
A terminal newline character does not result in an extra empty string (new in v0.14, october 2019).
(strings)Join the list of strings with a newline character.
(separator s &key omit-nulls limit start end)Split into subtrings (unlike cl-ppcre, without a regexp). If
omit-nulls is non-nil, zero-length substrings are omitted.
(split "+" "foo++bar") ;; => ("foo" "" "bar")
(split #\+ "foo++bar") ;; => ("foo" "" "bar")
(split "+" "foo++bar" :omit-nulls t) ;; => ("foo" "bar")
cl-ppcre has an inconsistency such that when the separator appears at the end, it doesn't return a trailing empty string. But we do since v0.14 (october, 2019).
(cl-ppcre:split " " "a b c ")
("a" "b" "c")
(str:split " " "a b c ")
("a" "b" "c" "")
Because it is a common pattern and it can be clearer than an option coming after many parenthesis.
(filename)Read the file and return its content as a string.
Example: (str:from-file "path/to/file.txt").
:external-format: if nil, the system default. Can be bound to :utf-8.
But you might just call
uiop's uiop:read-file-string
directly.
There is also uiop:read-file-lines.
(filename s)Write the string s to the file filename. If the file does not
exist, create it, if it already exists, replace it.
Options:
:if-does-not-exist: :create (default), :error:if-exists: :supersede (default), :append, :overwrite, :rename, :error,...Returns the string written to file.
(s)True if s is nil or the empty string:
(empty? nil) ;; => T
(empty? "") ;; => T
(empty? " ") ;; => NIL
See also str:non-empty-string-p, which adds a stringp check.
(s)True if s is empty or only contains whitespaces.
(blankp "") ;; => T
(blankp " ") ;; => T
(emptyp " ") ;; => NIL
See also str:non-blank-string-p.
(start s &key ignore-case)True if s starts with the substring start, nil otherwise. Ignore
case by default.
(starts-with? "foo" "foobar") ;; => T
(starts-with? "FOO" "foobar") ;; => NIL
(starts-with? "FOO" "foobar" :ignore-case t) ;; => T
Calls string= or string-equal depending on the case, with their
:start and :end delimiters.
(end s &key ignore-case)True if s ends with the substring end. Ignore case by default.
(ends-with? "bar" "foobar") ;; => T
(substring s &key (ignore-case nil))Return true if s contains substring, nil otherwise. Ignore the
case with :ignore-case t (don't ignore by default).
Based on a simple call to the built-in search (which returns the
position of the substring).
(items s)Return s if it is a common prefix (or suffix) between items.
See also uiop:string-prefix-p prefix s, which returns t if
prefix is a prefix of s,
and uiop:string-enclosed-p prefix s suffix, which returns t if s
begins with prefix and ends with suffix.
We use cl-change-case (go thank him and star the repo!).
The available functions are:
:no-case (s &key replacement)
:camel-case (s &key merge-numbers)
:dot-case
:header-case
:param-case
:pascal-case
:path-case
:sentence-case
:snake-case
:swap-case
:title-case
:constant-case
More documentation and examples are there.
(s) fixing a built-in suprise. (new in 0.11)The functions str:downcase, str:upcase and str:capitalize return
a new string. They call the built-in string-downcase,
string-upcase and string-capitalize respectively, but they fix
something surprising. When the argument is nil, the built-ins return
"nil" or "NIL" or "Nil", a string. Indeed, they work on anything:
(string-downcase nil) ;; => "nil" the string !
(str:downcase nil) ;; nil
(string-downcase :FOO) ;; => "foo"
(s)These functions return t if the given string contains at least one
letter and all its letters are lowercase or uppercase, respectively.
(is (downcasep " a+,. ") t "downcasep with one letter and punctuation is true.")
(is (downcasep " +,. ") nil "downcasep with only punctuation or spaces is false")
(s)alphap returns t if s contains at least one character and all characters are
alpha (as in "^[a-zA-Z]+$").
lettersp works for unicode letters too.
(is (alphap "abcdeé") nil "alphap is nil with accents")
(is (lettersp "éß") t "lettersp is t with accents and ß")
(s)alphanump returns t if s contains at least one character and all characters are alphanumeric (as in ^[a-zA-Z0-9]+$).
lettersnump also works on unicode letters (as in ^[\\p{L}a-zA-Z0-9]+$).
(s)Returns t if s contains at least one character and all characters are numerical (as for digit-char-p).
(s)Return t if s has at least one alpha, letter, alphanum character (as with alphanumericp).
(old new s)Replace the first occurence of old by new in s. Arguments are not regexs.
(replace-first "a" "o" "faa") ;; => "foa"
Uses cl-ppcre:regex-replace but quotes the user input to not treat it as a regex.
(old new s)Replace all occurences of old by new in s. Arguments are not regexs.
(replace-all "a" "o" "faa") ;; => "foo"
Uses cl-ppcre:regex-replace-all but quotes the user input to not treat it as a regex.
Remove the punctuation characters from s, replace them with
replacement (defaults to a space) and strip continuous whitespace.
(str:remove-punctuation "I say: - 'Hello, world?'") ;; => "I say Hello world"
Use str:no-case to remove punctuation and return the string as lower-case.
(list-of-strings) (renamed in 0.9)(renamed from common-prefix in v0.9)
Find the common prefix between strings.
Example: (str:prefix '(\"foobar\" \"foozz\")) => "foo"
Uses the built-in mismatch, that returns the position at which
the strings fail to match.
Return a string or nil when the input is the void list.
(list-of-strings)Find the common suffix between strings.
(substring s &key start end)Counts the non-overlapping occurrences of substring in s.
You could also count only the ocurrencies between start and end.
Examples:
(count-substring "abc" "abcxabcxabc")
;; => 3
(count-substring "abc" "abcxabcxabc" :start 3 :end 7)
;; => 1
(alist key)Returns the value of a cons cell in alist with key key, when key is a string.
The second return value is the cons cell, if any was matched.
The arguments are in the opposite order of cl:assoc's, but are consistent
with alexandria:assoc-value (and str).
(s-assoc-value '(("hello" . 1) ("world" . 2)) "world")
;; => 1
;; ("world" . 2)
(alexandria:assoc-value '(("hello" . 1)) "hello")
;; NIL
(alexandria:assoc-value '(("hello" . 1)) "hello" :test #'string=)
;; 1
;; ("hello" . 1)
(assoc "hello" '(("hello" . 1)))
;; NIL
(assoc "hello" '(("hello" . 1)) :test #'string=)
;; ("hello" . 1)
(cdr *)
;; 1
A case-like macro that works with strings (CL case's test function is
eql, and that isn't enough for strings).
Example:
(str:string-case input
("foo" (do something))
(nil (print "input is nil")
(otherwise (print "non of the previous forms was caught.")))
You might also like pattern matching. The example below with trivia is very similar:
(trivia:match "hey"
("hey" (print "it matched"))
(otherwise :nothing))
Note that there is also http://quickdocs.org/string-case/.
split and lines. A trailing separator now returns a trailing empty string.Before:
(str:split " " "a b c ")
("a" "b" "c") ;; like cl-ppcre:split
Now:
(str:split " " "a b c ")
("a" "b" "c" "")
remove-punctuation that did not respect the case. Use no-case for this.pad, pad-[left, right, center].prune, renamed to shorten.:limit to split.insertdowncasep, alphap, has-x and friends).str:downcase, str:upcase and str:capitalize, that fix the nil argument surprise.split doesn't fix cl-ppcre's inconsistency anymore (when the separator appears at the end). See issue #18. So (str:split "xx" "fooxxbarxx") doesn't return a trailing "".s-lasts-first and friends return nil when appropriate, not "".s-first , s-rest and s-nthprefix and suffix functions and predicates.prune.string-caseversionsplit-omit-nulls (QL, january 2018)common-prefixfrom-file and to-file.substring.Test with prove.
(ql:quickload :str.test) (load "test/test-str.lisp")
Inspired by the famous Emacs Lisp's [s.el](https://github.com/magnars/s
Next: Files, Previous: Introduction, Up: Top [Contents][Index]
The main system appears first, followed by any subsystem dependency.
| • The str system |
vindarel <vindarel@mailz.org>
vindarel <vindarel@mailz.org>
(:git "git@github.com:vindarel/cl-str.git")
MIT
Modern, consistent and terse Common Lisp string manipulation library.
[](http://quickdocs.org/cl-str)
# A modern and consistent Common Lisp string manipulation library
(ql:quickload "str")
also on [Ultralisp](http://ultralisp.org/).
Why ?
* modernity, simplicity and discoverability:
- ‘(str:trim s)‘ instead of ‘ (string-trim ’(#\Space #\Newline #\Backspace #\Tab #\Linefeed #\Page #\Return #\Rubout) s))‘,
or ‘str:concat strings‘ instead of an unusual ‘format‘ construct; one discoverable library instead of many;
* consistence and composability, where ‘s‘ is always the last argument, which makes it
easier to feed pipes and arrows.
* fixing built-in surprises: ‘(string-downcase nil‘) => ‘"nil"‘ the string, whereas ‘(str:downcase nil)‘ => ‘nil‘.
The only dependency is ‘cl-ppcre‘.
<!– markdown-toc start - Don’t edit this section. Run M-x markdown-toc-refresh-toc –>
**Table of Contents**
- [A modern and consistent Common Lisp string manipulation library](#a-modern-and-consistent-common-lisp-string-manipulation-library)
- [Install](#install)
- [Global parameters](#global-parameters)
- [Functions](#functions)
- [Tweak whitespace](#tweak-whitespace)
- [trim ‘(s)‘](#trim-s)
- [collapse-whitespaces ‘(s)‘](#collapse-whitespaces-s)
- [To longer strings](#to-longer-strings)
- [join ‘(separator list-of-strings)‘](#join-separator-list-of-strings)
- [concat ‘(&rest strings)‘](#concat-rest-strings)
- [insert ‘(string/char index s)‘](#insert-stringchar-index-s)
- [repeat ‘(count s)‘](#repeat-count-s)
- [add-prefix, add-suffix ‘(items s)‘](#add-prefix-add-suffix-items-s)
- [pad ‘(len s &key (pad-side :right) (pad-char #\Space))‘, pad-left, pad-right, pad-center (new in 0.16, 2019/12)](#pad-len-s-key-pad-side-right-pad-char-space-pad-left-pad-right-pad-center-new-in-016-201912)
- [To shorter strings](#to-shorter-strings)
- [substring ‘(start end s)‘](#substring-start-end-s)
- [s-first ‘(s)‘](#s-first-s)
- [s-last ‘(s)‘](#s-last-s)
- [s-rest ‘(s)‘](#s-rest-s)
- [s-nth ‘(n s)‘](#s-nth-n-s)
- [shorten ‘(len s &key ellipsis)‘](#shorten-len-s-key-ellipsis)
- [To and from lists](#to-and-from-lists)
- [words ‘(s)‘](#words-s)
- [unwords ‘(strings)‘](#unwords-strings)
- [lines ‘(s &key omit-nulls)‘](#lines-s-key-omit-nulls)
- [unlines ‘(strings)‘](#unlines-strings)
- [split ‘(separator s &key omit-nulls limit start end)‘](#split-separator-s-key-omit-nulls-limit-start-end)
- [split-omit-nulls](#split-omit-nulls)
- [To and from files](#to-and-from-files)
- [from-file ‘(filename)‘](#from-file-filename)
- [to-file ‘(filename s)‘](#to-file-filename-s)
- [Predicates](#predicates)
- [empty?, emptyp ‘(s)‘](#empty-emptyp-s)
- [blank?, blankp ‘(s)‘](#blank-blankp-s)
- [starts-with?, starts-with-p ‘(start s &key ignore-case)‘](#starts-with-starts-with-p-start-s-key-ignore-case)
- [ends-with?, ends-with-p ‘(end s &key ignore-case)‘](#ends-with-ends-with-p-end-s-key-ignore-case)
- [contains?, containsp ‘(substring s &key (ignore-case nil))‘](#contains-containsp-substring-s-key-ignore-case-nil)
- [prefix?, prefixp and suffix?, suffixp ‘(items s)‘](#prefix-prefixp-and-suffix-suffixp-items-s)
- [Case](#case)
- [Functions to change case: camel-case, snake-case,... (new in 0.15, 2019/11)](#functions-to-change-case-camel-case-snake-case-new-in-015-201911)
- [downcase, upcase, capitalize ‘(s)‘ fixing a built-in suprise. (new in 0.11)](#downcase-upcase-capitalize-s-fixing-a-built-in-suprise-new-in-011)
- [downcasep, upcasep ‘(s)‘](#downcasep-upcasep-s)
- [alphap, lettersp ‘(s)‘](#alphap-lettersp-s)
- [alphanump, lettersnump ‘(s)‘](#alphanump-lettersnump-s)
- [digitp ‘(s)‘](#digitp-s)
- [has-alpha-p, has-letters-p, has-alphanum-p ‘(s)‘](#has-alpha-p-has-letters-p-has-alphanum-p-s)
- [Others](#others)
- [replace-first ‘(old new s)‘](#replace-first-old-new-s)
- [replace-all ‘(old new s)‘](#replace-all-old-new-s)
- [remove-punctuation (s &key replacement)](#remove-punctuation-s-key-replacement)
- [prefix ‘(list-of-strings)‘ (renamed in 0.9)](#prefix-list-of-strings-renamed-in-09)
- [suffix ‘(list-of-strings)‘](#suffix-list-of-strings)
- [count-substring ‘(substring s &key start end)‘](#count-substring-substring-s-key-start-end)
- [s-assoc-value ‘(alist key)‘](#s-assoc-value-alist-key)
- [Macros](#macros)
- [string-case](#string-case)
- [Changelog](#changelog)
- [Dev and test](#dev-and-test)
- [See also](#see-also)
<!– markdown-toc end –>
## Install
Install with [Quicklisp](https://www.quicklisp.org/beta/):
(ql:quickload :str)
Check its version:
(str:version)
To get a newer version, you need to update the Quicklisp dist (think
of QL as Debian’s apt rather than pip/npm/etc):
(ql:update-dist "quicklisp")
Don’t have a full Common Lisp development environment yet ? Get
[Portacle](https://shinmera.github.io/portacle/), a portable and
multiplatform development environment shipping Emacs, Quicklisp, SBCL
and Git. See also [editor
support](https://lispcookbook.github.io/cl-cookbook/editor-support.html)
(Vim, Lem, Atom, Eclipse,…).
## Global parameters
Some parameters are common to various functions and often used:
‘:ignore-case‘ and ‘:omit-nulls‘.
Consequently we can also manage them with global parameters:
~~~lisp
(let ((str:*ignore-case* t))
(str:ends-with? "BAR" "foobar"))
~~~
is equivalent to
~~~lisp
(str:ends-with? "BAR" "foobar" :ignore-case t)
~~~
## Functions
### Tweak whitespace
#### trim ‘(s)‘
Remove whitespaces at the beginning and end of ‘s‘.
“‘lisp
(trim " rst ") ;; => "rst"
“‘
Also ‘trim-left‘ and ‘trim-right‘.
Uses the built-in
[string-trim](https://lispcookbook.github.io/cl-cookbook/strings.html#trimming-blanks-from-the-ends-of-a-string)
where whitespaces are ‘’(#\Space #\Newline #\Backspace #\Tab #\Linefeed #\Page #\Return #\Rubout)‘.
#### collapse-whitespaces ‘(s)‘
Ensure there is only one space character between words. Remove newlines.
~~~lisp
(collapse-whitespaces "foo bar
baz")
;; "foo bar baz"
;;T
~~~
### To longer strings
#### join ‘(separator list-of-strings)‘
Join strings in list ‘list-of-strings‘ with ‘separator‘ (either a string or a char) in between.
“‘lisp
(join " " ’("foo" "bar" "baz")) ;; => "foo bar baz"
(join #\Space ’("foo" "bar" "baz")) ;; => "foo bar baz"
“‘
It uses the ‘{‘ iteration [format](http://jtra.cz/stuff/lisp/sclr/format.html) directive. See also this [quick reference](http://clqr.boundp.org/download.html):
(format nil "~{~a+~}" ’(:a :b :c)) ;; the + is the separator
;; => "A+B+C+"
We use the caret directive ("escape upward") to not print the
separator in the end:
(format nil "~{~a~^+~}" ’(:a :b :c))
;; => "A+B+C"
#### concat ‘(&rest strings)‘
Join strings into one.
“‘lisp
(concat "f" "o" "o") ;; => "foo"
“‘
Simple call of the built-in [concatenate](https://lispcookbook.github.io/cl-cookbook/strings.html#concatenating-strings).
We actually also have ‘uiop:strcat‘.
#### insert ‘(string/char index s)‘
Insert the given string (or character) at the index ‘index‘ into ‘s‘ and return a
new string.
If ‘index‘ is out of bounds, just return ‘s‘.
“‘lisp
(str:insert "l" 2 "helo") ; => "hello"
(str:insert "o" 99 "hell") : => "hell"
“‘
#### repeat ‘(count s)‘
Make a string of ‘s‘ repeated ‘count‘ times.
“‘lisp
(repeat 3 "foo") ;; => "foofoofoo"
“‘
#### add-prefix, add-suffix ‘(items s)‘
Respectively prepend or append ‘s‘ to the front of each item.
#### pad ‘(len s &key (pad-side :right) (pad-char #\Space))‘, pad-left, pad-right, pad-center (new in 0.16, 2019/12)
Fill ‘s‘ with characters until it is of the given length. By default,
add spaces on the right:
~~~lisp
(str:pad 10 "foo")
"foo "
~~~
* ‘pad-side‘: one of ‘:right‘ (the default), ‘:left‘ or ‘:center‘. See ‘*pad-side*‘.
* ‘pad-char‘: the padding character (or string of one character). Defaults to a space. See ‘*pad-char*‘.
~~~lisp
(str:pad 10 "foo" :pad-side :center :pad-char "+")
"+++foo++++"
~~~
If the given length is smaller than the length o ‘s‘, return ‘s‘.
Filling with spaces can easily be done with format:
~~~lisp
(format nil "~va" len s) ;; => "foo "
(format nil "~v@a" 10 "foo") ;; => " foo" (with @)
~~~
### To shorter strings
#### substring ‘(start end s)‘
Return the substring of ‘s‘ from ‘start‘ to ‘end‘.
It uses ‘subseq‘ with differences:
* argument order, s at the end
* ‘start‘ and ‘end‘ can be lower than 0 or bigger than the length of s.
* for convenience ‘end‘ can be nil or t to denote the end of the string.
Examples:
“‘lisp
(is "abcd" (substring 0 t "abcd") "t denotes the end of the string")
(is "abcd" (substring 0 nil "abcd") "nil too")
(is "abcd" (substring 0 100 "abcd") "end can be too large")
(is "abc" (substring 0 -1 "abcd") "end can be negative. Counts from the end.")
(is "" (substring 0 -100 "abcd") "end can be negative and too low")
(is "" (substring 100 1 "abcd") "start can be too big")
(is "abcd" (substring -100 4 "abcd") "start can also be too low")
(is "" (substring 2 1 "abcd") "start is bigger than end")
“‘
#### s-first ‘(s)‘
Return the first letter of ‘s‘.
Examples:
“‘lisp
(s-first "foobar") ;; => "f"
(s-first "") ;; => ""
“‘
#### s-last ‘(s)‘
Return the last letter of ‘s‘.
#### s-rest ‘(s)‘
Return the rest substring of ‘s‘.
Examples:
“‘lisp
(s-rest "foobar") ;; => "oobar"
(s-rest "") ;; => ""
“‘
#### s-nth ‘(n s)‘
Return the nth letter of ‘s‘.
Examples:
“‘lisp
(s-nth 3 "foobar") ;; => "b"
(s-nth 3 "") ;; => ""
“‘
You could also use
~~~lisp
(elt "test" 1)
;; => #\e
(string (elt "test" 1))
;; => "e"
~~~
#### shorten ‘(len s &key ellipsis)‘
If ‘s‘ is longer than ‘len‘, truncate it and add an ellipsis at the
end (‘...‘ by default). ‘s‘ is cut down to ‘len‘ minus the length of
the ellipsis (3 by default).
Optionally, give an ‘:ellipsis‘ keyword argument. Also set it globally
with ‘*ellipsis*‘.
~~~lisp
(shorten 8 "hello world")
;; => "hello..."
(shorten 3 "hello world")
;; => "..."
(shorten 8 "hello world" :ellipsis "-")
;; => "hello w-"
(let ((*ellipsis* "-"))
(shorten 8 "hello world"))
;; => "hello w-"
~~~
### To and from lists
#### words ‘(s)‘
Return list of words, which were delimited by whitespace.
#### unwords ‘(strings)‘
Join the list of strings with a whitespace.
#### lines ‘(s &key omit-nulls)‘
Split string by newline character and return list of lines.
A terminal newline character does *not* result in an extra empty string
(new in **v0.14**, october 2019).
#### unlines ‘(strings)‘
Join the list of strings with a newline character.
#### split ‘(separator s &key omit-nulls limit start end)‘
Split into subtrings (unlike cl-ppcre, without a regexp). If
‘omit-nulls‘ is non-nil, zero-length substrings are omitted.
“‘lisp
(split "+" "foo++bar") ;; => ("foo" "" "bar")
(split #\+ "foo++bar") ;; => ("foo" "" "bar")
(split "+" "foo++bar" :omit-nulls t) ;; => ("foo" "bar")
“‘
cl-ppcre has an inconsistency such that when the separator appears at
the end, it doesn’t return a trailing empty string. But we do **since
v0.14** (october, 2019).
~~~lisp
(cl-ppcre:split " " "a b c ")
("a" "b" "c")
(str:split " " "a b c ")
("a" "b" "c" "")
~~~
#### split-omit-nulls
Because it is a common pattern and it can be clearer than an option
coming after many parenthesis.
### To and from files
#### from-file ‘(filename)‘
Read the file and return its content as a string.
Example: ‘(str:from-file "path/to/file.txt")‘.
‘:external-format‘: if nil, the system default. Can be bound to ‘:utf-8‘.
But you might just call
[uiop’s ‘uiop:read-file-string‘](https://github.com/fare/asdf/blob/master/uiop/stream.lisp#L445)
directly.
There is also ‘uiop:read-file-lines‘.
#### to-file ‘(filename s)‘
Write the string ‘s‘ to the file ‘filename‘. If the file does not
exist, create it, if it already exists, replace it.
Options:
* ‘:if-does-not-exist‘: ‘:create‘ (default), ‘:error‘
* ‘:if-exists‘: ‘:supersede‘ (default), ‘:append‘, ‘:overwrite‘, ‘:rename‘, ‘:error‘,...
Returns the string written to file.
### Predicates
#### empty?, emptyp ‘(s)‘
True if ‘s‘ is nil or the empty string:
“‘lisp
(empty? nil) ;; => T
(empty? "") ;; => T
(empty? " ") ;; => NIL
“‘
See also ‘str:non-empty-string-p‘, which adds a ‘stringp‘ check.
#### blank?, blankp ‘(s)‘
True if ‘s‘ is empty or only contains whitespaces.
(blankp "") ;; => T
(blankp " ") ;; => T
(emptyp " ") ;; => NIL
See also ‘str:non-blank-string-p‘.
#### starts-with?, starts-with-p ‘(start s &key ignore-case)‘
True if ‘s‘ starts with the substring ‘start‘, nil otherwise. Ignore
case by default.
(starts-with? "foo" "foobar") ;; => T
(starts-with? "FOO" "foobar") ;; => NIL
(starts-with? "FOO" "foobar" :ignore-case t) ;; => T
Calls ‘string=‘ or ‘string-equal‘ depending on the case, with their
‘:start‘ and ‘:end‘ delimiters.
#### ends-with?, ends-with-p ‘(end s &key ignore-case)‘
True if ‘s‘ ends with the substring ‘end‘. Ignore case by default.
(ends-with? "bar" "foobar") ;; => T
#### contains?, containsp ‘(substring s &key (ignore-case nil))‘
Return true if ‘s‘ contains ‘substring‘, nil otherwise. Ignore the
case with ‘:ignore-case t‘ (don’t ignore by default).
Based on a simple call to the built-in ‘search‘ (which returns the
position of the substring).
#### prefix?, prefixp and suffix?, suffixp ‘(items s)‘
Return ‘s‘ if it is a common prefix (or suffix) between items.
See also ‘uiop:string-prefix-p prefix s‘, which returns ‘t‘ if
‘prefix‘ is a prefix of ‘s‘,
and ‘uiop:string-enclosed-p prefix s suffix‘, which returns ‘t‘ if ‘s‘
begins with ‘prefix‘ and ends with ‘suffix‘.
### Case
#### Functions to change case: camel-case, snake-case,... (new in 0.15, 2019/11)
We use
[cl-change-case](https://github.com/rudolfochrist/cl-change-case/) (go
thank him and star the repo!).
The available functions are:
“‘
:no-case (s &key replacement)
:camel-case (s &key merge-numbers)
:dot-case
:header-case
:param-case
:pascal-case
:path-case
:sentence-case
:snake-case
:swap-case
:title-case
:constant-case
“‘
More documentation and examples are there.
#### downcase, upcase, capitalize ‘(s)‘ fixing a built-in suprise. (new in 0.11)
The functions ‘str:downcase‘, ‘str:upcase‘ and ‘str:capitalize‘ return
a new string. They call the built-in ‘string-downcase‘,
‘string-upcase‘ and ‘string-capitalize‘ respectively, but they fix
something surprising. When the argument is ‘nil‘, the built-ins return
"nil" or "NIL" or "Nil", a *string*. Indeed, they work on anything:
(string-downcase nil) ;; => "nil" the string !
(str:downcase nil) ;; nil
(string-downcase :FOO) ;; => "foo"
#### downcasep, upcasep ‘(s)‘
These functions return ‘t‘ if the given string contains at least one
letter and all its letters are lowercase or uppercase, respectively.
“‘lisp
(is (downcasep " a+,. ") t "downcasep with one letter and punctuation is true.")
(is (downcasep " +,. ") nil "downcasep with only punctuation or spaces is false")
“‘
#### alphap, lettersp ‘(s)‘
‘alphap‘ returns t if ‘s‘ contains at least one character and all characters are
alpha (as in ‘"^[a-zA-Z]+$"‘).
‘lettersp‘ works for unicode letters too.
~~~lisp
(is (alphap "abcdeé") nil "alphap is nil with accents")
(is (lettersp "éß") t "lettersp is t with accents and ß")
~~~
#### alphanump, lettersnump ‘(s)‘
‘alphanump‘ returns t if ‘s‘ contains at least one character and all characters are alphanumeric (as in ‘^[a-zA-Z0-9]+$‘).
‘lettersnump‘ also works on unicode letters (as in ‘^[\\p{L}a-zA-Z0-9]+$‘).
#### digitp ‘(s)‘
Returns t if ‘s‘ contains at least one character and all characters are numerical (as for ‘digit-char-p‘).
#### has-alpha-p, has-letters-p, has-alphanum-p ‘(s)‘
Return t if ‘s‘ has at least one alpha, letter, alphanum character (as with ‘alphanumericp‘).
### Others
#### replace-first ‘(old new s)‘
Replace the first occurence of ‘old‘ by ‘new‘ in ‘s‘. Arguments are not regexs.
“‘lisp
(replace-first "a" "o" "faa") ;; => "foa"
“‘
Uses
[cl-ppcre:regex-replace](http://weitz.de/cl-ppcre/#regex-replace)
but quotes the user input to not treat it as a regex.
#### replace-all ‘(old new s)‘
Replace all occurences of ‘old‘ by ‘new‘ in ‘s‘. Arguments are not regexs.
“‘lisp
(replace-all "a" "o" "faa") ;; => "foo"
“‘
Uses
[cl-ppcre:regex-replace-all](http://weitz.de/cl-ppcre/#regex-replace-all)
but quotes the user input to not treat it as a regex.
#### remove-punctuation (s &key replacement)
Remove the punctuation characters from ‘s‘, replace them with
‘replacement‘ (defaults to a space) and strip continuous whitespace.
~~~lisp
(str:remove-punctuation "I say: - ’Hello, world?’") ;; => "I say Hello world"
~~~
Use ‘str:no-case‘ to remove punctuation and return the string as lower-case.
#### prefix ‘(list-of-strings)‘ (renamed in 0.9)
(renamed from ‘common-prefix‘ in v0.9)
Find the common prefix between strings.
Example: ‘(str:prefix ’(\"foobar\" \"foozz\"))‘ => \"foo\"
Uses the built-in ‘mismatch‘, that returns the position at which
the strings fail to match.
Return a string or nil when the input is the void list.
#### suffix ‘(list-of-strings)‘
Find the common suffix between strings.
#### count-substring ‘(substring s &key start end)‘
Counts the non-overlapping occurrences of ‘substring‘ in ‘s‘.
You could also count only the ocurrencies between ‘start‘ and ‘end‘.
Examples:
~~~ lisp
(count-substring "abc" "abcxabcxabc")
;; => 3
~~~
~~~lisp
(count-substring "abc" "abcxabcxabc" :start 3 :end 7)
;; => 1
~~~
#### s-assoc-value ‘(alist key)‘
Returns the value of a cons cell in ‘alist‘ with key ‘key‘, when ‘key‘ is a string.
The second return value is the cons cell, if any was matched.
The arguments are in the opposite order of ‘cl:assoc‘’s, but are consistent
with ‘alexandria:assoc-value‘ (and ‘str‘).
“‘lisp
(s-assoc-value ’(("hello" . 1) ("world" . 2)) "world")
;; => 1
;; ("world" . 2)
(alexandria:assoc-value ’(("hello" . 1)) "hello")
;; NIL
(alexandria:assoc-value ’(("hello" . 1)) "hello" :test #’string=)
;; 1
;; ("hello" . 1)
(assoc "hello" ’(("hello" . 1)))
;; NIL
(assoc "hello" ’(("hello" . 1)) :test #’string=)
;; ("hello" . 1)
(cdr *)
;; 1
“‘
## Macros
### string-case
A case-like macro that works with strings (CL case’s test function is
‘eql‘, and that isn’t enough for strings).
Example:
~~~lisp
(str:string-case input
("foo" (do something))
(nil (print "input is nil")
(otherwise (print "non of the previous forms was caught.")))
~~~
You might also like pattern matching. The example below with
[trivia](https://github.com/guicho271828/trivia/) is very similar:
~~~lisp
(trivia:match "hey"
("hey" (print "it matched"))
(otherwise :nothing))
~~~
Note that there is also http://quickdocs.org/string-case/.
## Changelog
* 0.14, october, 2019: fixed the cl-ppcre inconsistency in ‘split‘ and ‘lines‘. A trailing separator now returns a trailing empty string.
Before:
~~~lisp
(str:split " " "a b c ")
("a" "b" "c") ;; like cl-ppcre:split
~~~
Now:
~~~lisp
(str:split " " "a b c ")
("a" "b" "c" "")
~~~
* 0.17, april 2020: fixed ‘remove-punctuation‘ that did not respect the case. Use ‘no-case‘ for this.
* 0.16, november 2019: added ‘pad‘, ‘pad-[left, right, center]‘.
* 0.15, october 2019: added functions to change case (based on cl-change-case).
added remove-punctuation.
* august, 2019: deprecated ‘prune‘, renamed to ‘shorten‘.
* added ‘:limit‘ to ‘split‘.
* 0.13 june, 2019
- added ‘insert‘
* 0.12
- added case predicates (‘downcasep‘, ‘alphap‘, ‘has-x‘ and friends).
* 0.11 (Quicklisp end of march, 2019, also in Ultralisp)
- added ‘str:downcase‘, ‘str:upcase‘ and ‘str:capitalize‘, that fix the ‘nil‘ argument surprise.
* 0.10
- ‘split‘ doesn’t fix cl-ppcre’s inconsistency anymore (when the separator appears at the end). See issue #18. So ‘(str:split "xx" "fooxxbarxx")‘ doesn’t return a trailing ‘""‘.
- added ‘s-last‘
- ‘s-first‘ and friends return ‘nil‘ when appropriate, not ‘""‘.
* 0.9
- added ‘s-first‘ , ‘s-rest‘ and ‘s-nth‘
- added ‘prefix‘ and ‘suffix‘ functions and predicates.
- added ‘prune‘.
* 0.8 added ‘string-case‘
* 0.7 added ‘version‘
* 0.6 added ‘split-omit-nulls‘ (QL, january 2018)
* 0.5 added ‘common-prefix‘
* 0.4 added ‘from-file‘ and ‘to-file‘.
* 0.3 added ‘substring‘.
## Dev and test
Test with [prove](https://github.com/fukamachi/prove).
(ql:quickload :str.test)
(load "test/test-str.lisp")
## See also
* the [Common Lisp Cookbook](https://lispcookbook.github.io/cl-cookbook/strings.html), strings page.
Inspired by the famous Emacs Lisp’s [s.el](https://github.com/magnars/s.el).
0.17
str.asd (file)
str.lisp (file)
Files are sorted by type and then listed depth-first from the systems components trees.
| • Lisp files |
| • The str.asd file | ||
| • The str/str.lisp file |
Next: The str/str․lisp file, Previous: Lisp files, Up: Lisp files [Contents][Index]
str.asd
str (system)
Previous: The str․asd file, Up: Lisp files [Contents][Index]
str (system)
str.lisp
Next: Definitions, Previous: Files, Up: Top [Contents][Index]
Packages are listed by definition order.
| • The str package |
str.lisp (file)
common-lisp
Definitions are sorted by export status, category, package, and then by lexicographic order.
| • Exported definitions | ||
| • Internal definitions |
Next: Internal definitions, Previous: Definitions, Up: Definitions [Contents][Index]
| • Exported special variables | ||
| • Exported macros | ||
| • Exported functions |
Next: Exported macros, Previous: Exported definitions, Up: Exported definitions [Contents][Index]
Ellipsis to add to the end of a truncated string (see ‘shorten’).
Padding character to use with ‘pad’. It can be a string of one character.
The side of the string to add padding characters to. Can be one of :right, :left and :center.
Next: Exported functions, Previous: Exported special variables, Up: Exported definitions [Contents][Index]
A case-like macro that works with strings (case works only with symbols).
Example:
(str:string-case input
("foo" (do something))
(nil (print "input is nil")
(otherwise (print "none of the previous forms was caught")))
You might also like pattern matching. The example below with optima is very similar:
(optima:match "hey"
("hey" (print "it matched"))
(otherwise :nothing))
Note that there is also http://quickdocs.org/string-case/.
Previous: Exported macros, Up: Exported definitions [Contents][Index]
Prepend s to the front of each items.
Return t if ‘s’ contains at least one character and all characters are alphanumeric. See also ‘lettersnump’ which also works on unicode letters.
Return t if ‘s’ contains at least one character and all characters are alpha (in [a-zA-Z]). See also ‘lettersp’, which checks for unicode letters.
Return the capitalized version of ‘s’.
Calls the built-in ‘string-capitalize’, but returns nil if ‘s’ is
nil (instead of the string "Nil").
Ensure there is only one space character between words. Remove newlines.
Join all the string arguments into one string.
Return ‘t‘ if ‘s‘ contains ‘substring‘, nil otherwise. Ignore the case with ‘:ignore-case t‘. A simple call to the built-in ‘search‘ (which returns the position of the substring).
Return ‘t‘ if ‘s‘ contains ‘substring‘, nil otherwise. Ignore the case with ‘:ignore-case t‘. A simple call to the built-in ‘search‘ (which returns the position of the substring).
Return the non-overlapping occurrences of ‘substring’ in ‘s’.
You could also count only the ocurrencies between ‘start’ and ‘end’.
Examples:
(count-substring "abc" "abcxabcxabc")
;; => 3
(count-substring "abc" "abcxabcxabc" :start 3 :end 7)
;; => 1
Return t if ‘s’ contains at least one character and all characters are numerical.
Return the lowercase version of ‘s’.
Calls the built-in ‘string-downcase’, but returns nil if ‘s’ is
nil (instead of the string "nil").
Return t if all alphabetical characters of ‘s’ are lowercase, and ‘s’ contains at least one letter.
Return t if s ends with the substring ’end’, nil otherwise.
Return t if s ends with the substring ’end’, nil otherwise.
Read the file and return its content as a string.
It simply uses uiop:read-file-string. There is also uiop:read-file-lines.
Example: (str:from-file "path/to/file.txt" :external-format :utf-8)
- external-format: if nil, the system default. Can be bound to :utf-8.
Return t if ‘s’ has at least one alpha character ([a-zA-Z]).
Return t if ‘s’ has at least one alphanumeric character.
Return t if ‘s’ contains at least one letter (considering unicode, not only alpha characters).
Insert the given string (or character) at the ‘index’ into ‘s’ and return a new string.
If ‘index’ is out of bounds, ignore and return ‘s’.
Join all the strings of the list with a separator.
Return t if ‘s’ contains only letters (including unicode letters) and digits.
Return t if ‘s’ contains only letters (including unicode letters).
(alphap "éß") ;; => nil
(lettersp "éß") ;; => t
Split the string by newline characters and return a list of lines. A terminal newline character does NOT result in an extra empty string.
Return t if ‘s’ is a string and is non blank (it doesn’t exclusively contain whitespace characters).
Like ‘(not (blank? s))’, with a ‘stringp’ check. Useful in context.
Return t if ‘s’ is a string and is non-empty.
Like ‘(not (empty? s))’, with a ‘stringp’ check. Useful in context.
Fill ‘s’ with characters until it is of the given length. By default, add spaces on the right.
Filling with spaces can be done with format:
(format nil "~v@a" len s) ;; with or without the @ directive
‘pad-side’: to pad ‘:right’ (the default), ‘:left’ or ‘:center’.
‘pad-char’: padding character (or string of one character). Defaults to a space.
Find the common prefix between strings.
Uses the built-in ‘mismatch’, that returns the position at which
the strings fail to match.
Example: ‘(str:prefix ’("foobar" "foozz"))‘ => "foo"
- items: list of strings
- Return: a string.
Return s if s is common prefix between items.
Return s if s is common prefix between items.
Remove the punctuation characters from ‘s’, replace them with ‘replacement’ (defaults to a space) and strip continuous whitespace.
Make a string of S repeated COUNT times.
Replace all occurences of ‘old‘ by ‘new‘ in ‘s‘. Arguments are not regexs.
Replace the first occurence of ‘old‘ by ‘new‘ in ‘s‘. Arguments are not regexs.
Return the value of a cons cell in ‘alist’ with key ‘key’, tested
with ‘string=’.
The second return value is the cons cell.
Return the nth substring of ‘s’.
You could also use (string (elt "test" 1)) ;; => "e"
If s is longer than ‘len’, truncate it to this length and add the ‘*ellipsis*’ at the end ("..." by default). Cut it down to ‘len’ minus the length of the ellipsis.
Split s into substring by separator (cl-ppcre takes a regex, we do not).
‘limit’ limits the number of elements returned (i.e. the string is split at most ‘limit’ - 1 times).
Call split with :omit-nulls to t.
Can be clearer in certain situations.
Return t if s starts with the substring ’start’, nil otherwise.
Return t if s starts with the substring ’start’, nil otherwise.
Return the substring of ‘s’ from ‘start’ to ‘end’.
It uses ‘subseq’ with differences:
- argument order, s at the end
- ‘start’ and ‘end’ can be lower than 0 or bigger than the length of s.
- for convenience ‘end’ can be nil or t to denote the end of the string.
Find the common suffix between strings.
Uses the built-in ‘mismatch’, that returns the position at which
the strings fail to match.
Example: ‘(str:suffix ’("foobar" "zzbar"))‘ => "bar"
- items: list of strings
- Return: a string.
Return s if s is common suffix between items.
Return s if s is common suffix between items.
Write string ‘s’ to file ‘pathname’. If the file does not exist, create it (use ‘:if-does-not-exist’), if it already exists, replace its content (‘:if-exists’).
Returns the string written to file.
Remove whitespaces at the beginning and end of s.
@begin[lang=lisp](code)
(trim " foo ") ;; => "foo"
@end(code)
Join the list of strings with a newline character.
Join the list of strings with a whitespace.
Return the uppercase version of ‘s’.
Call the built-in ‘string-upcase’, but return nil if ‘s’ is
nil (instead of the string "NIL").
Return t if all alphabetical characters of ‘s’ are uppercase.
Return list of words, which were delimited by white space. If the optional limit is 0 (the default), trailing empty strings are removed from the result list (see cl-ppcre).
Previous: Exported definitions, Up: Definitions [Contents][Index]
| • Internal special variables | ||
| • Internal functions |
Next: Internal functions, Previous: Internal definitions, Up: Internal definitions [Contents][Index]
Previous: Internal special variables, Up: Internal definitions [Contents][Index]
Previous: Definitions, Up: Top [Contents][Index]
| • Concept index | ||
| • Function index | ||
| • Variable index | ||
| • Data type index |
Next: Function index, Previous: Indexes, Up: Indexes [Contents][Index]
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|---|
| Jump to: | F L S |
|---|
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| Jump to: | A B C D E F H I J L M N P R S T U V W |
|---|
| Jump to: | A B C D E F H I J L M N P R S T U V W |
|---|
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+
S |
|---|
| Jump to: | *
+
S |
|---|
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|---|
| Index Entry | Section | ||
|---|---|---|---|
| | |||
| P | |||
Package, str: | The str package | ||
| | |||
| S | |||
str: | The str system | ||
str: | The str package | ||
System, str: | The str system | ||
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| Jump to: | P S |
|---|