Package org.daiitech.naftah.builtin.utils

Class StringUtils

java.lang.Object

org.daiitech.naftah.builtin.utils.StringUtils

public final class StringUtils
extends Object

Utility class for performing various operations on String objects, including arithmetic, bitwise, and vectorized character-wise operations.

Supports both scalar and vector APIs for enhanced performance on large strings. The vector operations are backed by the ShortVector API.

This class also defines several functional constants used to map operations across strings.

This class is not instantiable.

Author:

Chakib Daii

Field Summary

Fields

Modifier and Type	Field	Description
static final BiFunction<Character,Character,Integer>	ADD	Character addition (based on ASCII code points).
static final BiFunction<ShortVector,ShortVector,ShortVector>	ADD_VEC	Vectorized addition of characters.
static final BiFunction<Character,Character,Integer>	AND	Bitwise AND operation for two characters.
static final BiFunction<ShortVector,ShortVector,ShortVector>	AND_VEC	Bitwise AND for vectorized characters.
static final Map<BiFunction<Character,Character,Integer>,BiFunction<ShortVector,ShortVector,ShortVector>>	BINARY_OP_MAP	Mapping from scalar binary operations to vectorized equivalents.
static final BiFunction<Character,Character,Integer>	DIV	Character division.
static final BiFunction<ShortVector,ShortVector,ShortVector>	DIV_VEC	Vectorized division of characters.
static final BiFunction<Character,Character,Integer>	MOD	Character modulo.
static final BiFunction<ShortVector,ShortVector,ShortVector>	MOD_VEC	Vectorized modulo operation (simulates floorMod).
static final BiFunction<Character,Character,Integer>	MUL	Character multiplication.
static final BiFunction<ShortVector,ShortVector,ShortVector>	MUL_VEC	Vectorized multiplication of characters.
static final Function<Character,Number>	NOT	Bitwise NOT operation for a single character.
static final Function<ShortVector,ShortVector>	NOT_VEC	Bitwise NOT for a vectorized character.
static final BiFunction<Character,Character,Integer>	OR	Bitwise OR operation for two characters.
static final BiFunction<ShortVector,ShortVector,ShortVector>	OR_VEC	Bitwise OR for vectorized characters.
static final Function<Character,Number>	POST_DECREMENT	Post-decrement a character (based on ASCII code).
static final Function<Character,Number>	POST_INCREMENT	Post-increment a character (based on ASCII code).
static final Function<Character,Number>	PRE_DECREMENT	Pre-decrement a character (based on ASCII code).
static final Function<ShortVector,ShortVector>	PRE_DECREMENT_VEC	Vectorized pre-decrement.
static final Function<Character,Number>	PRE_INCREMENT	Pre-increment a character (based on ASCII code).
static final Function<ShortVector,ShortVector>	PRE_INCREMENT_VEC	Vectorized pre-increment.
private static final VectorSpecies<Short>	SPECIES	Preferred vector species for character-based operations.
static final BiFunction<Character,Character,Integer>	SUBTRACT	Character subtraction.
static final BiFunction<ShortVector,ShortVector,ShortVector>	SUBTRACT_VEC	Vectorized subtraction of characters.
static final Map<Function<Character,Number>,Function<ShortVector,ShortVector>>	UNARY_OP_MAP	Mapping from scalar unary operations to vectorized equivalents.
static final Boolean	USE_VECTOR_API	Indicates whether vectorized operations should be used (controlled via JVM property).
static final int	VECTOR_THRESHOLD	Minimum string length for vectorized execution.
static final BiFunction<Character,Character,Integer>	XOR	Bitwise XOR operation for two characters.
static final BiFunction<ShortVector,ShortVector,ShortVector>	XOR_VEC	Bitwise XOR for vectorized characters.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	StringUtils()	Private constructor to prevent instantiation.

Method Summary

Modifier and Type	Method	Description
static String	add(String a, String b)	Concatenates two strings.
static String	and(String a, String b)	Performs bitwise AND between characters in two strings.
static String	applyOperation(String a, String b, BiFunction<Character,Character,Integer> operation)	Applies a binary character-wise operation to two strings.
static String	applyOperation(String a, Function<Character,Number> operation)	Applies a unary character-wise operation to a string.
static String	applyOperationScalar(String a, String b, BiFunction<Character,Character,Integer> operation)	Applies a scalar binary character-wise operation to two strings.
static String	applyOperationScalar(String a, Function<Character,Number> operation)	Applies a scalar unary character-wise operation to a string.
static String	applyOperationVectorized(String a, String b, BiFunction<Character,Character,Integer> operation, BiFunction<ShortVector,ShortVector,ShortVector> vectorOperation)	Applies a vectorized binary operation to two strings using ShortVector.
static String	applyOperationVectorized(String input, Function<Character,Number> scalarOperation, Function<ShortVector,ShortVector> vectorOperation)	Applies a vectorized unary operation using ShortVector.
static String	charWiseAdd(String a, String b)	Performs character-wise addition between two strings.
static String	charWiseDivide(String a, String b)	Performs character-wise division between two strings.
static String	charWiseModulo(String a, String b)	Performs character-wise modulo between two strings.
static String	charWiseMultiply(String a, String b)	Performs character-wise multiplication between two strings.
static String	charWiseSubtract(String a, String b)	Performs character-wise subtraction between two strings.
static int	compare(String a, String b)	Compares two strings lexicographically.
static String[]	divide(String s, int parts)	Splits a string into a specified number of parts.
static String[]	divide(String a, String delimiter)	Splits a string using the given delimiter.
static char	doApplyOperation(char aChar, char bChar, BiFunction<Character,Character,Integer> operation)	Applies a scalar binary operation on two characters.
static char	doApplyOperation(char aChar, Function<Character,Number> operation)	Applies a unary operation on a single character.
static boolean	equals(String a, String b)	Checks if two strings are equal.
static String	multiply(String s, int multiplier)	Repeats the given string a specified number of times.
static NaftahBugError	newNaftahInvalidEmptyInputStringCannotBeEmptyBugError()	Creates a NaftahBugError indicating that the input string was null or empty.
static NaftahBugError	newNaftahPartsCountExceedsStringLengthBugError()	Creates a NaftahBugError indicating that the number of parts exceeds the string length.
static NaftahBugError	newNaftahPartsCountMustBeGreaterThanZeroBugError()	Creates a NaftahBugError indicating that the number of parts is zero or negative.
static String	not(String a)	Performs bitwise NOT operation on each character of the string.
static String	or(String a, String b)	Performs bitwise OR between characters in two strings.
static String	postDecrement(String a)	Post-decrements each character in the string.
static String	postIncrement(String a)	Post-increments each character in the string.
static String	preDecrement(String a)	Pre-decrements each character in the string.
static String	preIncrement(String a)	Pre-increments each character in the string.
static int	stringToInt(String s)	Converts a string into an integer by summing its Unicode code points.
static String	subtract(String a, String b)	Removes all occurrences of b from a.
static String	xor(String a, String b)	Performs bitwise XOR between characters in two strings.

Methods inherited from class java.lang.Object

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

Field Details

XOR

public static final BiFunction<Character,Character,Integer> XOR

Bitwise XOR operation for two characters.

AND

public static final BiFunction<Character,Character,Integer> AND

Bitwise AND operation for two characters.

OR

public static final BiFunction<Character,Character,Integer> OR

Bitwise OR operation for two characters.

NOT

public static final Function<Character,Number> NOT

Bitwise NOT operation for a single character.

ADD

public static final BiFunction<Character,Character,Integer> ADD

Character addition (based on ASCII code points).

SUBTRACT

public static final BiFunction<Character,Character,Integer> SUBTRACT

Character subtraction.

MUL

public static final BiFunction<Character,Character,Integer> MUL

Character multiplication.

DIV

public static final BiFunction<Character,Character,Integer> DIV

Character division.

MOD

public static final BiFunction<Character,Character,Integer> MOD

Character modulo.

PRE_INCREMENT

public static final Function<Character,Number> PRE_INCREMENT

Pre-increment a character (based on ASCII code).

POST_INCREMENT

public static final Function<Character,Number> POST_INCREMENT

Post-increment a character (based on ASCII code).

PRE_DECREMENT

public static final Function<Character,Number> PRE_DECREMENT

Pre-decrement a character (based on ASCII code).

POST_DECREMENT

public static final Function<Character,Number> POST_DECREMENT

Post-decrement a character (based on ASCII code).

USE_VECTOR_API

public static final Boolean USE_VECTOR_API

Indicates whether vectorized operations should be used (controlled via JVM property).

VECTOR_THRESHOLD

public static final int VECTOR_THRESHOLD

Minimum string length for vectorized execution.

See Also:

• Constant Field Values

XOR_VEC

public static final BiFunction<ShortVector,ShortVector,ShortVector> XOR_VEC

Bitwise XOR for vectorized characters.

AND_VEC

public static final BiFunction<ShortVector,ShortVector,ShortVector> AND_VEC

Bitwise AND for vectorized characters.

OR_VEC

public static final BiFunction<ShortVector,ShortVector,ShortVector> OR_VEC

Bitwise OR for vectorized characters.

NOT_VEC

public static final Function<ShortVector,ShortVector> NOT_VEC

Bitwise NOT for a vectorized character.

ADD_VEC

public static final BiFunction<ShortVector,ShortVector,ShortVector> ADD_VEC

Vectorized addition of characters.

SUBTRACT_VEC

public static final BiFunction<ShortVector,ShortVector,ShortVector> SUBTRACT_VEC

Vectorized subtraction of characters.

MUL_VEC

public static final BiFunction<ShortVector,ShortVector,ShortVector> MUL_VEC

Vectorized multiplication of characters.

DIV_VEC

public static final BiFunction<ShortVector,ShortVector,ShortVector> DIV_VEC

Vectorized division of characters.

MOD_VEC

public static final BiFunction<ShortVector,ShortVector,ShortVector> MOD_VEC

Vectorized modulo operation (simulates floorMod).

PRE_INCREMENT_VEC

public static final Function<ShortVector,ShortVector> PRE_INCREMENT_VEC

Vectorized pre-increment.

PRE_DECREMENT_VEC

public static final Function<ShortVector,ShortVector> PRE_DECREMENT_VEC

Vectorized pre-decrement.

BINARY_OP_MAP

public static final Map<BiFunction<Character,Character,Integer>,BiFunction<ShortVector,ShortVector,ShortVector>> BINARY_OP_MAP

Mapping from scalar binary operations to vectorized equivalents.

UNARY_OP_MAP

public static final Map<Function<Character,Number>,Function<ShortVector,ShortVector>> UNARY_OP_MAP

Mapping from scalar unary operations to vectorized equivalents.

SPECIES

private static final VectorSpecies<Short> SPECIES

Preferred vector species for character-based operations.

Constructor Details

StringUtils

private StringUtils()

Private constructor to prevent instantiation. Always throws a NaftahBugError when called.

Method Details

equals

public static boolean equals(String a,
 String b)

Checks if two strings are equal.

Parameters:

a - the first string

b - the second string

Returns:

true if both strings are equal

compare

public static int compare(String a,
 String b)

Compares two strings lexicographically.

Parameters:

a - the first string

b - the second string

Returns:

a negative integer, zero, or a positive integer as a is less than, equal to, or greater than b

add

public static String add(String a,
 String b)

Concatenates two strings.

Parameters:

a - the first string

b - the second string

Returns:

the concatenated string

subtract

public static String subtract(String a,
 String b)

Removes all occurrences of b from a.

Parameters:

a - the original string

b - the substring to remove

Returns:

the resulting string

divide

public static String[] divide(String a,
 String delimiter)

Splits a string using the given delimiter.

Parameters:

a - the string to split

delimiter - the delimiter

Returns:

an array of substrings

divide

public static String[] divide(String s,
 int parts)

Splits a string into a specified number of parts.

Parameters:

s - the string to split

parts - the number of parts

Returns:

an array containing the parts

Throws:

NaftahBugError - if the string is empty, or if parts is invalid

multiply

public static String multiply(String s,
 int multiplier)

Repeats the given string a specified number of times.

Parameters:

s - the input string

multiplier - number of repetitions

Returns:

the repeated string

applyOperation

public static String applyOperation(String a,
 String b,
 BiFunction<Character,Character,Integer> operation)

Applies a binary character-wise operation to two strings.

- If either a or b is null, throws a NaftahBugError indicating invalid input. - If one string is empty, returns the other string as-is. - Otherwise, applies the provided character-wise operation. If vectorization is enabled and applicable, uses a vectorized implementation for performance.

Parameters:

a - the first string (must not be null)

b - the second string (must not be null)

operation - the character-wise binary operation (e.g. addition, subtraction)

Returns:

the resulting string after applying the operation

Throws:

NaftahBugError - if either a or b is null

applyOperationScalar

public static String applyOperationScalar(String a,
 String b,
 BiFunction<Character,Character,Integer> operation)

Applies a scalar binary character-wise operation to two strings.

Parameters:

a - the first string

b - the second string

operation - the binary operation

Returns:

the result string after applying the operation character-wise

applyOperationVectorized

public static String applyOperationVectorized(String a,
 String b,
 BiFunction<Character,Character,Integer> operation,
 BiFunction<ShortVector,ShortVector,ShortVector> vectorOperation)

Applies a vectorized binary operation to two strings using ShortVector.

Parameters:

a - the first string

b - the second string

operation - the scalar operation (for fallback)

vectorOperation - the vectorized operation

Returns:

the resulting string after applying the vectorized operation

doApplyOperation

public static char doApplyOperation(char aChar,
 char bChar,
 BiFunction<Character,Character,Integer> operation)

Applies a scalar binary operation on two characters.

Parameters:

aChar - the first character

bChar - the second character

operation - the binary operation

Returns:

the resulting character after applying the operation

charWiseAdd

public static String charWiseAdd(String a,
 String b)

Performs character-wise addition between two strings.

Parameters:

a - the first string

b - the second string

Returns:

the resulting string

charWiseSubtract

public static String charWiseSubtract(String a,
 String b)

Performs character-wise subtraction between two strings.

Parameters:

a - the first string

b - the second string

Returns:

the resulting string

charWiseMultiply

public static String charWiseMultiply(String a,
 String b)

Performs character-wise multiplication between two strings.

Parameters:

a - the first string

b - the second string

Returns:

the resulting string

charWiseDivide

public static String charWiseDivide(String a,
 String b)

Performs character-wise division between two strings.

Parameters:

a - the first string

b - the second string

Returns:

the resulting string

charWiseModulo

public static String charWiseModulo(String a,
 String b)

Performs character-wise modulo between two strings.

Parameters:

a - the first string

b - the second string

Returns:

the resulting string

xor

public static String xor(String a,
 String b)

Performs bitwise XOR between characters in two strings.

Parameters:

a - the first string

b - the second string

Returns:

the resulting string

and

public static String and(String a,
 String b)

Performs bitwise AND between characters in two strings.

Parameters:

a - the first string

b - the second string

Returns:

the resulting string

or

public static String or(String a,
 String b)

Performs bitwise OR between characters in two strings.

Parameters:

a - the first string

b - the second string

Returns:

the resulting string

applyOperation

public static String applyOperation(String a,
 Function<Character,Number> operation)

Applies a unary character-wise operation to a string.

Parameters:

a - the input string

operation - the unary character operation

Returns:

the resulting string

applyOperationScalar

public static String applyOperationScalar(String a,
 Function<Character,Number> operation)

Applies a scalar unary character-wise operation to a string.

Parameters:

a - the input string

operation - the unary character operation

Returns:

the resulting string

applyOperationVectorized

public static String applyOperationVectorized(String input,
 Function<Character,Number> scalarOperation,
 Function<ShortVector,ShortVector> vectorOperation)

Applies a vectorized unary operation using ShortVector.

Parameters:

input - the input string

scalarOperation - the scalar fallback operation

vectorOperation - the vector operation to apply

Returns:

the resulting string

doApplyOperation

public static char doApplyOperation(char aChar,
 Function<Character,Number> operation)

Applies a unary operation on a single character.

Parameters:

aChar - the input character

operation - the unary character operation

Returns:

the resulting character

not

public static String not(String a)

Performs bitwise NOT operation on each character of the string.

Parameters:

a - the input string

Returns:

the resulting string

preIncrement

public static String preIncrement(String a)

Pre-increments each character in the string.

Parameters:

a - the input string

Returns:

the resulting string

postIncrement

public static String postIncrement(String a)

Post-increments each character in the string.

Parameters:

a - the input string

Returns:

the resulting string

preDecrement

public static String preDecrement(String a)

Pre-decrements each character in the string.

Parameters:

a - the input string

Returns:

the resulting string

postDecrement

public static String postDecrement(String a)

Post-decrements each character in the string.

Parameters:

a - the input string

Returns:

the resulting string

stringToInt

public static int stringToInt(String s)

Converts a string into an integer by summing its Unicode code points.

Parameters:

s - the input string

Returns:

the sum of the code points

newNaftahInvalidEmptyInputStringCannotBeEmptyBugError

public static NaftahBugError newNaftahInvalidEmptyInputStringCannotBeEmptyBugError()

Creates a NaftahBugError indicating that the input string was null or empty.

Returns:

a new NaftahBugError with a message explaining the invalid input.

newNaftahPartsCountMustBeGreaterThanZeroBugError

public static NaftahBugError newNaftahPartsCountMustBeGreaterThanZeroBugError()

Creates a NaftahBugError indicating that the number of parts is zero or negative.

Returns:

a new NaftahBugError with a message explaining the invalid part count.

newNaftahPartsCountExceedsStringLengthBugError

public static NaftahBugError newNaftahPartsCountExceedsStringLengthBugError()

Creates a NaftahBugError indicating that the number of parts exceeds the string length.

Returns:

a new NaftahBugError with a message explaining the constraint violation.