Package org.jline.reader.impl

Class ReaderUtils

java.lang.Object

org.jline.reader.impl.ReaderUtils

public class ReaderUtils
extends Object

Utility methods for LineReader implementations.

This class provides helper methods for working with LineReader variables and options. It includes methods for retrieving variables of different types (string, boolean, integer, long) with default values, checking if options are set, and calculating string distances for completion matching.

These utilities are primarily used by the LineReader implementation classes to access configuration values in a consistent way, with proper type conversion and default handling.

See Also:

• LineReader.getVariable(String)
• LineReader.isSet(LineReader.Option)

Method Summary

Modifier and Type	Method	Description
static int	distance(String word, String cand)	Calculates the edit distance between a word and a candidate string.
static boolean	getBoolean(LineReader reader, String name, boolean def)	Gets a boolean variable from a LineReader with a default value.
static int	getInt(LineReader reader, String name, int def)	Gets an integer variable from a LineReader with a default value.
static long	getLong(LineReader reader, String name, long def)	Gets a long variable from a LineReader with a default value.
static String	getString(LineReader reader, String name, String def)	Gets a string variable from a LineReader with a default value.
static boolean	isSet(LineReader reader, LineReader.Option option)	Checks if a LineReader option is set.

Methods inherited from class java.lang.Object

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

Method Details

isSet

public static boolean isSet(LineReader reader,
 LineReader.Option option)

Checks if a LineReader option is set.

This method safely handles null readers by returning false.

Parameters:

reader - the LineReader to check, may be null

option - the option to check

Returns:

true if the reader is not null and the option is set, false otherwise

getString

public static String getString(LineReader reader,
 String name,
 String def)

Gets a string variable from a LineReader with a default value.

This method safely handles null readers by returning the default value.

Parameters:

reader - the LineReader to get the variable from, may be null

name - the name of the variable to get

def - the default value to return if the variable is not set or the reader is null

Returns:

the variable value as a string, or the default value

getBoolean

public static boolean getBoolean(LineReader reader,
 String name,
 boolean def)

Gets a boolean variable from a LineReader with a default value.

This method safely handles null readers by returning the default value. String values are converted to boolean according to these rules:

• Empty string, "on", "1", and "true" (case-insensitive) are considered true
• All other strings are considered false

Parameters:

reader - the LineReader to get the variable from, may be null

name - the name of the variable to get

def - the default value to return if the variable is not set or the reader is null

Returns:

the variable value as a boolean, or the default value

getInt

public static int getInt(LineReader reader,
 String name,
 int def)

Gets an integer variable from a LineReader with a default value.

This method safely handles null readers by returning the default value. String values are parsed as integers, with a fallback to 0 if parsing fails.

Parameters:

reader - the LineReader to get the variable from, may be null

name - the name of the variable to get

def - the default value to return if the variable is not set or the reader is null

Returns:

the variable value as an integer, or the default value

getLong

public static long getLong(LineReader reader,
 String name,
 long def)

Gets a long variable from a LineReader with a default value.

This method safely handles null readers by returning the default value. String values are parsed as longs, with a fallback to 0 if parsing fails.

Parameters:

reader - the LineReader to get the variable from, may be null

name - the name of the variable to get

def - the default value to return if the variable is not set or the reader is null

Returns:

the variable value as a long, or the default value

distance

public static int distance(String word,
 String cand)

Calculates the edit distance between a word and a candidate string.

This method is used for fuzzy matching in completion. It uses the Levenshtein distance algorithm to determine how similar two strings are, with special handling for candidates that are longer than the word being matched.

Parameters:

word - the word to match against

cand - the candidate string to check

Returns:

the edit distance between the strings (lower values indicate closer matches)