tech.tablesaw.columns.strings

Interface StringMapFunctions

All Superinterfaces:

Column<String>, Comparator<String>, Iterable<String>

All Known Implementing Classes:

AbstractStringColumn, StringColumn, TextColumn

public interface StringMapFunctions
extends Column<String>

String utility functions. Each function takes one or more String columns as input and produces another Column as output. The resulting column need not be a string column.

This code was developed as part of Apache Commons Text.

Method Summary

Modifier and Type	Method and Description
default StringColumn	abbreviate(int maxWidth) Abbreviates a String using ellipses.
default StringColumn	capitalize() Capitalizes each String changing the first character of each to title case as per Character.toTitleCase(int), as if in a sentence.
default StringColumn	commonPrefix(Column<String> column2)
default StringColumn	commonSuffix(Column<String> column2)
default StringColumn	concatenate(Column... stringColumns) Return a copy of this column with the corresponding value of each column argument appended to each element.
default StringColumn	concatenate(Object... stringsToAppend) Return a copy of this column with the given string appended to each element
default DoubleColumn	countTokens(String separator)
default DoubleColumn	distance(Column<String> column2) Returns a column containing the levenshtein distance between the two given string columns
default StringColumn	format(String formatString)
default StringColumn	join(String separator, Column... columns) Return a copy of this column with the given string appended
default DoubleColumn	length() Returns a column containing the character length of each string in this column The returned column is the same size as the original
default StringColumn	lowerCase()
default StringColumn	padEnd(int minLength, char padChar)
default StringColumn	padStart(int minLength, char padChar)
default DoubleColumn	parseDouble() Returns an Double containing all the values of this string column as doubles, assuming all the values are stringified doubles in the first place.
default FloatColumn	parseFloat() Returns an Float containing all the values of this string column as floats, assuming all the values are stringified floats in the first place.
default IntColumn	parseInt() Returns an IntColumn containing all the values of this string column as integers, assuming all the values are stringified ints in the first place.
default StringColumn	repeat(int times) Repeats each the column's values elementwise, concatinating the results into a new StringColumn
default StringColumn	replaceAll(String[] regexArray, String replacement) Creates a new column, replacing each string in this column with a new string formed by replacing any substring that matches the regex
default StringColumn	replaceAll(String regex, String replacement)
default StringColumn	replaceFirst(String regex, String replacement)
default StringColumn	substring(int start) Returns a column containing the substrings from start to the end of the input
default StringColumn	substring(int start, int end)
default StringColumn	tokenizeAndRemoveDuplicates(String separator)
default StringColumn	tokenizeAndSort() Splits on Whitespace and returns the lexicographically sorted result.
default StringColumn	tokenizeAndSort(String separator)
default StringColumn	tokens(String separator) Returns a column of arbitrary size containing each token in this column, where a token is defined using the given separator.
default StringColumn	trim()
default StringColumn	uniqueTokens(String separator) Returns a column of arbitrary size containing each unique token in this column, where a token is defined using the given separator, and uniqueness is calculated across the entire column
default StringColumn	upperCase()

Methods inherited from interface tech.tablesaw.columns.Column

allMatch, anyMatch, append, append, append, appendCell, appendCell, appendMissing, appendObj, asBytes, asList, asObjectArray, asStringColumn, byteSize, clear, columnWidth, contains, copy, count, count, countMissing, countUnique, emptyCopy, emptyCopy, filter, first, get, getString, getUnformattedString, inRange, interpolate, isEmpty, isMissing, isMissing, isNotMissing, lag, last, lead, map, map, mapInto, max, max, min, min, name, noneMatch, print, reduce, reduce, removeMissing, rolling, rowComparator, sampleN, sampleX, set, set, set, set, set, set, setMissing, setMissingTo, setName, size, sortAscending, sortDescending, sorted, subset, summary, title, type, unique, where

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Methods inherited from interface java.util.Comparator

compare, comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Method Detail

upperCase

default StringColumn upperCase()

lowerCase

default StringColumn lowerCase()

capitalize

default StringColumn capitalize()

Capitalizes each String changing the first character of each to title case as per Character.toTitleCase(int), as if in a sentence. No other characters are changed.

 capitalize(null)  = null
 capitalize("")    = ""
 capitalize("cat") = "Cat"
 capitalize("cAt") = "CAt"
 capitalize("'cat'") = "'cat'"
 

repeat

default StringColumn repeat(int times)

Repeats each the column's values elementwise, concatinating the results into a new StringColumn

Parameters:

times - The number of repeat desired

  repeat("", 2)   = ""
  repeat("cat", 3) = "catcatcat"
 

Returns:

the new StringColumn

trim

default StringColumn trim()

replaceAll

default StringColumn replaceAll(String regex,
                                String replacement)

replaceFirst

default StringColumn replaceFirst(String regex,
                                  String replacement)

substring

default StringColumn substring(int start,
                               int end)

substring

default StringColumn substring(int start)

Returns a column containing the substrings from start to the end of the input

Throws:

StringIndexOutOfBoundsException - if any string in the column is shorter than start

abbreviate

default StringColumn abbreviate(int maxWidth)

Abbreviates a String using ellipses. This will turn "Now is the time for all good men" into "Now is the time for..."

Parameters:

maxWidth - the maximum width of the resulting strings, including the elipses.

format

default StringColumn format(String formatString)

parseInt

default IntColumn parseInt()

Returns an IntColumn containing all the values of this string column as integers, assuming all the values are stringified ints in the first place. Otherwise an exception is thrown

Returns:

An IntColumn containing ints parsed from the strings in this column

parseDouble

default DoubleColumn parseDouble()

Returns an Double containing all the values of this string column as doubles, assuming all the values are stringified doubles in the first place. Otherwise an exception is thrown

Returns:

A DoubleColumn containing doubles parsed from the strings in this column

parseFloat

default FloatColumn parseFloat()

Returns an Float containing all the values of this string column as floats, assuming all the values are stringified floats in the first place. Otherwise an exception is thrown

Returns:

A FloatColumn containing floats parsed from the strings in this column

padEnd

default StringColumn padEnd(int minLength,
                            char padChar)

padStart

default StringColumn padStart(int minLength,
                              char padChar)

commonPrefix

default StringColumn commonPrefix(Column<String> column2)

commonSuffix

default StringColumn commonSuffix(Column<String> column2)

distance

default DoubleColumn distance(Column<String> column2)

Returns a column containing the levenshtein distance between the two given string columns

join

default StringColumn join(String separator,
                          Column... columns)

Return a copy of this column with the given string appended

Parameters:

columns - the column to append

Returns:

the new column

concatenate

default StringColumn concatenate(Object... stringsToAppend)

Return a copy of this column with the given string appended to each element

Parameters:

stringsToAppend - the stringified objects to append

Returns:

the new column

concatenate

default StringColumn concatenate(Column... stringColumns)

Return a copy of this column with the corresponding value of each column argument appended to each element. getString is used to ensure the value returned by the args are strings

Parameters:

stringColumns - the string columns to append

Returns:

the new column

replaceAll

default StringColumn replaceAll(String[] regexArray,
                                String replacement)

Creates a new column, replacing each string in this column with a new string formed by replacing any substring that matches the regex

Parameters:

regexArray - the regex array to replace

replacement - the replacement array

Returns:

the new column

tokenizeAndSort

default StringColumn tokenizeAndSort(String separator)

countTokens

default DoubleColumn countTokens(String separator)

uniqueTokens

default StringColumn uniqueTokens(String separator)

Returns a column of arbitrary size containing each unique token in this column, where a token is defined using the given separator, and uniqueness is calculated across the entire column

NOTE: Unlike other map functions, this method produces a column whose size may be different from the source, so they cannot safely be combined in a table.

Parameters:

separator - the delimiter used in the tokenizing operation

Returns:

a new column

tokens

default StringColumn tokens(String separator)

Returns a column of arbitrary size containing each token in this column, where a token is defined using the given separator.

NOTE: Unlike other map functions, this method produces a column whose size may be different from the source, so they cannot safely be combined in a table.

Parameters:

separator - the delimiter used in the tokenizing operation

Returns:

a new column

length

default DoubleColumn length()

Returns a column containing the character length of each string in this column The returned column is the same size as the original

tokenizeAndSort

default StringColumn tokenizeAndSort()

Splits on Whitespace and returns the lexicographically sorted result.

Returns:

a StringColumn

tokenizeAndRemoveDuplicates

default StringColumn tokenizeAndRemoveDuplicates(String separator)