no.motif

Class Strings

java.lang.Object

no.motif.Strings

public final class Strings
extends Object

Functions operating on strings.

Field Summary

Fields

Modifier and Type	Field and Description
static Predicate<String>	alphabetic Alphabetic strings are at least one character, and all letters.
static Predicate<String>	alphanumeric Alphanumeric strings are at least one character, and all digits and/or letters.
static Predicate<String>	blank A blank string is either null, empty, or all characters are whitespace.
static Fn<String,Iterable<Byte>>	bytes Yields the bytes of a String.
static Fn2<Object,Object,String>	concat Concatenate a string with the string representation of an arbitrary object, i.e.
static Fn<String,Integer>	length Gives the length of a string, i.e.
static Fn<String,String>	lowerCased Convert a string to lower case.
static Predicate<String>	nonblank A nonblank string has at least one character, and must contain at least one character which is not whitespace.
static Predicate<String>	numeric A numeric string must have at least one character, and all of them must be digits.
static Fn<String,String>	reversed Yields the given string with its characters in reversed order.
static Fn<String,Iterable<Character>>	toChars Splits a string into characters.
static Fn<String,Double>	toDouble Converts a string to a double value using Double.valueOf(String).
static Fn<String,Integer>	toInt Converts a string to a int value using Integer.valueOf(String).
static Fn<String,Long>	toLong Converts a string to a long value using Long.valueOf(String).
static Fn<String,String>	trimmed Trims a string, removing all leading and trailing whitespace.
static Fn<String,String>	upperCased Convert a string to upper case

Method Summary

Modifier and Type	Method and Description
static Fn<String,String>	after(String substring) Inside strings, searches for the first occurence of a substring, and yields the rest of the string after the substring occurence, not including the substring itself.
static Fn<String,String>	afterLast(String substring) Inside strings, searches for the last occurence of a substring, and yields the rest of the string after the substring occurence, not including the substring itself.
static Fn<String,Iterable<String>>	allBetween(String openSubstring, String closeSubstring) Yield all strings occurring _between_ two substrings.
static Predicate<String>	allChars(Predicate<Character> valid) Predicate verifying that all characters in a string satifies a given predicate.
static Fn<Object,String>	append(String suffix) Create a new strings by appending a suffix.
static Fn<String,String>	before(Fn<? super String,Integer> index) Yields substrings before a position index.
static Fn<String,String>	before(int index) Yields substrings before a position index.
static Fn<String,String>	before(String substring) Inside strings, searches for the first occurence of a substring, and yields the the string before the substring occurence, not including the substring itself.
static Fn<String,String>	beforeLast(String substring) Inside strings, searches for the last occurence of a substring, and yields the the string before the substring occurence, not including the substring itself.
static Fn<String,String>	between(String openSubstring, String closeSubstring) Yield the string _between_ two substrings.
static Fn<String,String>	betweenOuter(String openSubstring, String closeSubstring) Yield the string _between_ two outermost substrings.
static Predicate<String>	contains(CharSequence charSequence) Determines if a substring is present in a string.
static Predicate<String>	endsWith(String suffix) Determines if a string ends with a given suffix string.
static Fn<String,String>	first(int charAmount) Get at most a given amount of the first characters of strings.
static Fn<String,String>	from(Fn<? super String,Integer> index) Yields substrings from a position index.
static Fn<String,String>	from(int index) Yields substrings from a position index.
static Predicate<String>	hasLength(int exactLength) Evaluate if strings are of a exact length.
static Predicate<String>	hasLength(Predicate<? super Integer> accepted) Evaluate if strings have accepted lengths.
static Fn<Object,String>	inBetween(String prefix, String suffix) Insert strings in between a prefix and a suffix.
static Fn<String,Integer>	indexOf(char c) Yields index position of first occurence of a char, or null if the char cannot be found.
static Fn<String,Integer>	indexOf(String substring) Yields index position of first occurence of a substring, or null if the substring cannot be found.
static Fn<String,String>	last(int charAmount) Get at most a given amount of the last characters of strings.
static Fn<String,Integer>	lastIndexOf(char c) Yields index position of last occurence of a char, or null if the char cannot be found.
static Fn<String,Integer>	lastIndexOf(String substring) Yields index position of last occurence of a substring, or null if the substring cannot be found.
static Predicate<String>	matches(String regex) Does a regular expression match on strings.
static Predicate<String>	nonblankAllChars(Predicate<Character> valid) Predicate verifying that strings are not blank and each char satisfies a given predicate.
static Fn<Object,String>	prepend(String prefix) Create a new strings by prepending a prefix.
static Fn<String,String>	repeat(int times) Repeats a string a given amount of times.
static Fn<String,String>	repeat(int times, String separator) Repeats a string, insterting given separator, a given amount of times.
static Fn<String,Iterable<String>>	splittingOn(char character) Split a string on each occurence of a char delimiter.
static Fn<String,Iterable<String>>	splittingOn(Predicate<? super Character> character) Split a string into several on any character passing the given Character predicate.
static Fn<String,Iterable<String>>	splittingOn(String substring) Split a string on each occurence of a substring.
static Predicate<String>	startsWith(String prefix) Determines if a string starts with a given prefix string.
static Fn<String,String>	substring(Fn<? super String,Integer> beginIndex, Fn<? super String,Integer> endIndex)
static Fn<String,String>	substring(int beginIndex, int endIndex) Extract substring from strings.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

toInt

public static final Fn<String,Integer> toInt

Converts a string to a int value using Integer.valueOf(String). If the string is null, 0 is yielded.

toLong

public static final Fn<String,Long> toLong

Converts a string to a long value using Long.valueOf(String). If the string is null, 0 is yielded.

toDouble

public static final Fn<String,Double> toDouble

Converts a string to a double value using Double.valueOf(String). If the string is null, 0 is yielded.

toChars

public static final Fn<String,Iterable<Character>> toChars

Splits a string into characters.

bytes

public static final Fn<String,Iterable<Byte>> bytes

Yields the bytes of a String.

See Also:

String.getBytes()

blank

public static final Predicate<String> blank

A blank string is either null, empty, or all characters are whitespace.

nonblank

public static final Predicate<String> nonblank

A nonblank string has at least one character, and must contain at least one character which is not whitespace.

numeric

public static final Predicate<String> numeric

A numeric string must have at least one character, and all of them must be digits.

alphanumeric

public static final Predicate<String> alphanumeric

Alphanumeric strings are at least one character, and all digits and/or letters.

alphabetic

public static final Predicate<String> alphabetic

Alphabetic strings are at least one character, and all letters.

trimmed

public static final Fn<String,String> trimmed

Trims a string, removing all leading and trailing whitespace.

lowerCased

public static final Fn<String,String> lowerCased

Convert a string to lower case.

upperCased

public static final Fn<String,String> upperCased

Convert a string to upper case

length

public static final Fn<String,Integer> length

Gives the length of a string, i.e. the amount of characters. null yields length 0.

concat

public static final Fn2<Object,Object,String> concat

Concatenate a string with the string representation of an arbitrary object, i.e. reduces two strings to one.

reversed

public static final Fn<String,String> reversed

Yields the given string with its characters in reversed order.

Method Detail

allChars

public static final Predicate<String> allChars(Predicate<Character> valid)

Predicate verifying that all characters in a string satifies a given predicate.

Parameters:

valid - The predicate evaluating all characters in a string.

nonblankAllChars

public static final Predicate<String> nonblankAllChars(Predicate<Character> valid)

Predicate verifying that strings are not blank and each char satisfies a given predicate.

Parameters:

valid -

hasLength

public static final Predicate<String> hasLength(int exactLength)

Evaluate if strings are of a exact length. nulls are considered to have length zero.

hasLength

public static final Predicate<String> hasLength(Predicate<? super Integer> accepted)

Evaluate if strings have accepted lengths. nulls are considered to have length zero.

Parameters:

accepted - The predicate evaluating accepted length.

Returns:

The predicate evaluating string length.

contains

public static Predicate<String> contains(CharSequence charSequence)

Determines if a substring is present in a string. A string never contains null, nor does null contain any substring.

Parameters:

charSequence - The substring to find.

Returns:

The predicate.

startsWith

public static Predicate<String> startsWith(String prefix)

Determines if a string starts with a given prefix string.

Parameters:

prefix - The prefix.

Returns:

The predicate.

endsWith

public static Predicate<String> endsWith(String suffix)

Determines if a string ends with a given suffix string.

Parameters:

suffix - The suffix.

Returns:

The predicate.

matches

public static Predicate<String> matches(String regex)

Does a regular expression match on strings.

Parameters:

regex - The regular expression to use for matching.

Returns:

the predicate.

prepend

public static Fn<Object,String> prepend(String prefix)

Create a new strings by prepending a prefix.

Parameters:

prefix - the prefix to prepend

append

public static Fn<Object,String> append(String suffix)

Create a new strings by appending a suffix.

Parameters:

suffix - the suffix to append

substring

public static Fn<String,String> substring(int beginIndex,
                                          int endIndex)

Extract substring from strings. As this function simply delegates to String.substring(int, int), it may throw an IndexOutOfBoundsException if the given indexes are invalid.

Parameters:

beginIndex - The index of the first character to include.

endIndex - The index to end the extraction.

substring

public static Fn<String,String> substring(Fn<? super String,Integer> beginIndex,
                                          Fn<? super String,Integer> endIndex)

first

public static Fn<String,String> first(int charAmount)

Get at most a given amount of the first characters of strings. If the string is shorter than the amount, the original string is returned.

last

public static Fn<String,String> last(int charAmount)

Get at most a given amount of the last characters of strings. If the string is shorter than the amount, the original string is returned.

inBetween

public static Fn<Object,String> inBetween(String prefix,
                                          String suffix)

Insert strings in between a prefix and a suffix.

Parameters:

prefix - The prefix to appear before the string.

suffix - The suffix to appear after the string

repeat

public static Fn<String,String> repeat(int times)

Repeats a string a given amount of times.

Parameters:

times - The amount of times to repeat the string.

repeat

public static Fn<String,String> repeat(int times,
                                       String separator)

Repeats a string, insterting given separator, a given amount of times.

Parameters:

times - The amount of times to repeat the string.

separator - The separator string to insert between the repeating strings.

after

public static Fn<String,String> after(String substring)

Inside strings, searches for the first occurence of a substring, and yields the rest of the string after the substring occurence, not including the substring itself.

Passing null to the Fn always yields null

If the substring is not found (or it is null), then null is returned.

If the substring is the empty string, the original string is returned.

Parameters:

substring - the substring to search for.

afterLast

public static Fn<String,String> afterLast(String substring)

Inside strings, searches for the last occurence of a substring, and yields the rest of the string after the substring occurence, not including the substring itself.

Passing null to the Fn always yields null

If the substring is not found, or if it is null, then null is returned. If the substring is empty, the empty string is returned.

Parameters:

substring - the substring to search for.

from

public static Fn<String,String> from(int index)

Yields substrings from a position index.

See Also:

from(Fn)

from

public static Fn<String,String> from(Fn<? super String,Integer> index)

Yields substrings from a position index. If the given index Fn yields null, then null is returned. If a positive index out of bounds with the length of the string is yielded, the empty string is returned.

A negative index value is invalid and will throw an StringIndexOutOfBoundsException.

Passing the null-String always yields null.

Parameters:

index - The Fn to resolve the index.

before

public static Fn<String,String> before(String substring)

Inside strings, searches for the first occurence of a substring, and yields the the string before the substring occurence, not including the substring itself.

Passing null to the Fn always yields null

If the substring is null, the original string is returned. If the substring is not found, null is returned.

If the substring is the empty string, or found from the beginning of the string, the empty string is returned.

Parameters:

substring - the substring to search for.

beforeLast

public static Fn<String,String> beforeLast(String substring)

Inside strings, searches for the last occurence of a substring, and yields the the string before the substring occurence, not including the substring itself.

Passing null to the Fn always yields null

If the substring is null or empty, the original string is returned. If the substring is not found, null is returned.

Parameters:

substring - the substring to search for.

before

public static Fn<String,String> before(int index)

Yields substrings before a position index.

See Also:

before(Fn)

before

public static Fn<String,String> before(Fn<? super String,Integer> index)

Yields substrings before a position index. If the given index Fn yields null, or a positive index out of bounds with the length of the string, the original string is returned.

A negative index is invalid and will throw an StringIndexOutOfBoundsException.

Passing the null-String always yields null.

Parameters:

index - The Fn to resolve the index.

between

public static Fn<String,String> between(String openSubstring,
                                        String closeSubstring)

Yield the string _between_ two substrings. The substrings will be the first possible matches, which means between("x", "y") applied to the string "xxyy" will yield "x".

Parameters:

openSubstring -

closeSubstring -

betweenOuter

public static Fn<String,String> betweenOuter(String openSubstring,
                                             String closeSubstring)

Yield the string _between_ two outermost substrings. This means betweenOuter("x", "y") applied to the string "xxyy" will yield "xy".

Parameters:

openSubstring -

closeSubstring -

allBetween

public static Fn<String,Iterable<String>> allBetween(String openSubstring,
                                                     String closeSubstring)

Yield all strings occurring _between_ two substrings.

Parameters:

openSubstring -

closeSubstring -

indexOf

public static Fn<String,Integer> indexOf(char c)

Yields index position of first occurence of a char, or null if the char cannot be found.

See Also:

String.indexOf(int)

lastIndexOf

public static Fn<String,Integer> lastIndexOf(char c)

Yields index position of last occurence of a char, or null if the char cannot be found.

See Also:

String.indexOf(int)

indexOf

public static Fn<String,Integer> indexOf(String substring)

Yields index position of first occurence of a substring, or null if the substring cannot be found.

See Also:

String.indexOf(String)

lastIndexOf

public static Fn<String,Integer> lastIndexOf(String substring)

Yields index position of last occurence of a substring, or null if the substring cannot be found.

See Also:

String.indexOf(String)

splittingOn

public static Fn<String,Iterable<String>> splittingOn(String substring)

Split a string on each occurence of a substring. The substring is not included in the resulting strings, and any consecutive substring are treated as one delimiter instance.

Parameters:

substring -

splittingOn

public static Fn<String,Iterable<String>> splittingOn(char character)

Split a string on each occurence of a char delimiter. The splitting character is not included in the resulting strings, and any consecutive occurrences of the character are treated as one delimiter instance.

Parameters:

character - the delimiter character

splittingOn

public static Fn<String,Iterable<String>> splittingOn(Predicate<? super Character> character)

Split a string into several on any character passing the given Character predicate. The characters accepted by the predicate is not included in the resulting strings, and any consecutive accepted characters are treated as one delimiter instance.

Parameters:

character - the predicate which decides if a character is a delimiter.