非常教程

Clojure 1.8参考手册

Clojure 1.8

clojure.string

完整名称空间名称:clojure.string

概述

Clojure String utilities

It is poor form to (:use clojure.string). Instead, use require
with :as to specify a prefix, e.g.

(ns your.namespace.here
  (:require [clojure.string :as str]))

Design notes for clojure.string:

1. Strings are objects (as opposed to sequences). As such, the
   string being manipulated is the first argument to a function;
   passing nil will result in a NullPointerException unless
   documented otherwise. If you want sequence-y behavior instead,
   use a sequence.

2. Functions are generally not lazy, and call straight to host
   methods where those are available and efficient.

3. Functions take advantage of String implementation details to
   write high-performing loop/recurs instead of using higher-order
   functions. (This is not idiomatic in general-purpose application
   code.)

4. When a function is documented to accept a string argument, it
   will take any implementation of the correct *interface* on the
   host platform. In Java, this is CharSequence, which is more
   general than String. In ordinary usage you will almost always
   pass concrete strings. If you are doing something unusual,
   e.g. passing a mutable implementation of CharSequence, then
   thread-safety is your responsibility.

公共变量和函数

blank?功能

Usage: (blank? s)
True if s is nil, empty, or contains only whitespace.

在Clojure版本1.2中添加

来源

capitalize函数

Usage: (capitalize s)
Converts first character of the string to upper-case, all other
characters to lower-case.

在Clojure版本1.2中添加

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ends-with? 函数

Usage: (ends-with? s substr)
True if s ends with substr.

在Clojure版本1.8中添加

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逃逸函数

Usage: (escape s cmap)
Return a new string, using cmap to escape each character ch
from s as follows:

If (cmap ch) is nil, append ch to the new string.
If (cmap ch) is non-nil, append (str (cmap ch)) instead.

在Clojure版本1.2中添加

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includes?函数

Usage: (includes? s substr)
True if s includes substr.

在Clojure版本1.8中添加

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指数剥离

Usage: (index-of s value)
       (index-of s value from-index)
Return index of value (string or char) in s, optionally searching
forward from from-index or nil if not found.

在Clojure版本1.8中添加

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加入函数

Usage: (join coll)
       (join separator coll)
Returns a string of all elements in coll, as returned by (seq coll),
separated by an optional separator.

在Clojure版本1.2中添加

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最后一个指数 函数

Usage: (last-index-of s value)
       (last-index-of s value from-index)
Return last index of value (string or char) in s, optionally
searching backward from from-index or nil if not found.

在Clojure版本1.8中添加

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下例函数

Usage: (lower-case s)
Converts string to all lower-case.

在Clojure版本1.2中添加

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re-quote-replacement函数

Usage: (re-quote-replacement replacement)
Given a replacement string that you wish to be a literal
replacement for a pattern match in replace or replace-first, do the
necessary escaping of special characters in the replacement.

在Clojure版本1.5中添加

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替换函数

Usage: (replace s match replacement)
Replaces all instance of match with replacement in s.

match/replacement can be:

string / string
char / char
pattern / (string or function of match).

See also replace-first.

The replacement is literal (i.e. none of its characters are treated
specially) for all cases above except pattern / string.

For pattern / string, $1, $2, etc. in the replacement string are
substituted with the string that matched the corresponding
parenthesized group in the pattern.  If you wish your replacement
string r to be used literally, use (re-quote-replacement r) as the
replacement argument.  See also documentation for
java.util.regex.Matcher's appendReplacement method.

Example:
(clojure.string/replace "Almost Pig Latin" #"\b(\w)(\w+)\b" "$2$1ay")
-> "lmostAay igPay atinLay"

在Clojure版本1.2中添加

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replace-first函数

Usage: (replace-first s match replacement)
Replaces the first instance of match with replacement in s.

match/replacement can be:

char / char
string / string
pattern / (string or function of match).

See also replace.

The replacement is literal (i.e. none of its characters are treated
specially) for all cases above except pattern / string.

For pattern / string, $1, $2, etc. in the replacement string are
substituted with the string that matched the corresponding
parenthesized group in the pattern.  If you wish your replacement
string r to be used literally, use (re-quote-replacement r) as the
replacement argument.  See also documentation for
java.util.regex.Matcher's appendReplacement method.

Example:
(clojure.string/replace-first "swap first two words"
                              #"(\w+)(\s+)(\w+)" "$3$2$1")
-> "first swap two words"

在Clojure版本1.2中添加

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逆函数

Usage: (reverse s)
Returns s with its characters reversed.

在Clojure版本1.2中添加

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分裂函数

Usage: (split s re)
       (split s re limit)
Splits string on a regular expression.  Optional argument limit is
the maximum number of splits. Not lazy. Returns vector of the splits.

在Clojure版本1.2中添加

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分行线函数

Usage: (split-lines s)
Splits s on \n or \r\n.

在Clojure版本1.2中添加

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starts-with?函数

Usage: (starts-with? s substr)
True if s starts with substr.

在Clojure版本1.8中添加

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微调函数

Usage: (trim s)
Removes whitespace from both ends of string.

在Clojure版本1.2中添加

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trim-newline函数

Usage: (trim-newline s)
Removes all trailing newline \n or return \r characters from
string.  Similar to Perl's chomp.

在Clojure版本1.2中添加

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三元函数

Usage: (triml s)
Removes whitespace from the left side of string.

在Clojure版本1.2中添加

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微调函数

Usage: (trimr s)
Removes whitespace from the right side of string.

在Clojure版本1.2中添加

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上案例函数

Usage: (upper-case s)
Converts string to all upper-case.

在Clojure版本1.2中添加

来源

 © Rich Hickey

使用EclipsePublicLicense 1.0授权。

https://clojure.github.io/Clojure/clojure.string-api.html

Clojure 1.8

Clojure 是一种运行在 Java 平台上的 Lisp 方言,Lisp 是一种以表达性和功能强大著称的编程语言,但人们通常认为它不太适合应用于一般情况,而 Clojure 的出现彻底改变了这一现状。如今,在任何具备 Java 虚拟机的地方,您都可以利用 Lisp 的强大功能。

版本 1.8
发布版本 1.8

Clojure 1.8目录

1.Clojure 1.8