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String Functions

New functions for the string type, implemented by Pluto.

New Functions​

string.split​

Splits a string by a separator.

Parameters​

  1. The string to split.
  2. The separator to split a string by. This can be any string.

Returns​

A table.

Example​

Splitting a string by a single character.
local s = "hello world, how is everyone doing?"
local r = string.split(s, " ")
--[[
    The value of 'r':
    {
        "hello",
        "world,",
        "how",
        "is",
        "everyone",
        "doing?"
    }
--]]
Splitting a string by a substring.
local s = "helloHALLOWORLDworld,HALLOWORLDhowHALLOWORLDisHALLOWORLDeveryoneHALLOWORLDdoing?"
local r = string.split(s, "HALLOWORLD")
--[[
    The value of 'r':
    {
        "hello",
        "world,",
        "how",
        "is",
        "everyone",
        "doing?"
    }
--]]

string.lfind​

Returns the index of where a substring starts. Begins searching at the left side of the string.

Parameters​

  1. The string to search.
  2. The substring to search for.

Returns​

An integer for the index of the substring, or nil if the substring was not found.

Example​

Basic Usage
local s = "hello world"
local r = string.lfind(s, "world") --> 7

string.rfind​

Returns the index of where a substring starts. Begins searching at the right side of the string.

Parameters​

  1. The string to search.
  2. The substring to search for.

Returns​

An integer for the index of the substring, or nil if the substring was not found.

Example​

Basic Usage
local s = "hello world"
local r = string.rfind(s, "world") --> 7

string.strip​

Strips characters from both ends of a string.

Parameters​

  1. The string to strip.
  2. A string of characters to strip.

Returns​

The new string.

Example​

Basic Usage
local s = "{}|hello world{|}"
local r = string.strip(s, "{}|") --> "hello world"

string.lstrip​

Strips characters from the left side of a string.

Parameters​

  1. The string to strip.
  2. A string of characters to strip.

Returns​

The new string.

Example​

Basic Usage
local s = "<{}|hello world>{|}"
local r = string.strip(s, "{}|") --> "<hello world>{|}"

string.rstrip​

Strips characters from the right side of a string.

Parameters​

  1. The string to strip.
  2. A string of characters to strip.

Returns​

The new string.

Example​

Basic Usage
local s = "<{}|hello world>{|}"
local r = string.strip(s, "{}|") --> "<{}|<hello world>"

string.isascii​

Checks if a string is entirely composed of ASCII characters.

Parameters​

  1. The string to check.

Returns​

A Boolean.

Example​

Basic Usage
local s = "HELLOWORLD123"
local r = string.isascii(r) --> true
info

This would exclude any multi-byte characters, like emojis.

string.islower​

Checks if a string is entirely composed of lowercase characters.

Parameters​

  1. The string to check.

Returns​

A Boolean.

Example​

Basic Usage
local s = "helloworld"
local r = string.islower(r) --> true
info

Whitespace characters are not lowercase characters.

string.isalpha​

Checks if a string is entirely composed of alphabetic characters.

Parameters​

  1. The string to check.

Returns​

A Boolean.

Example​

Basic Usage
local s = "HELLOWORLD"
local r = string.isalpha(r) --> true
info

Whitespace characters are not alphabetic characters.

string.isupper​

Checks if a string is entirely composed of uppercase characters.

Parameters​

  1. The string to check.

Returns​

A Boolean.

Example​

Basic Usage
local s = "HELLOWORLD"
local r = string.isupper(r) --> true
info

Whitespace characters are not uppercase characters.

string.isalnum​

Checks if a string is entirely composed of alphanumeric characters.

Parameters​

  1. The string to check.

Returns​

A Boolean.

Example​

Basic Usage
local s = "HELLOWORLD123"
local r = string.isalnum(r) --> true
info

Whitespace characters are not alphanumeric characters.

string.contains​

Checks if a string contains a substring.

Parameters​

  1. The string to check.
  2. The substring to check for.

Returns​

A boolean.

Example​

Basic Usage
local s = "hello world"
local r = string.contains(s, "worl") --> true

string.casefold​

Compares two strings, agnostic of any capitalization.

Parameters​

  1. The first string to compare.
  2. The second string to compare.

Returns​

A boolean.

Example​

Basic Usage
local s1 = "hello world"
local s2 = "heLLo WoRlD"
local r1 = string.casefold(s1, s2) --> true

string.partition​

Splits a string once, on the first occurance of a separator.

Parameters​

  1. The string to partition.
  2. The separator to partition the string by.
  3. A boolean specifying whether to search from the right. By default, this is false, which starts at the left.

Returns​

Two strings: A substring for all the content before the first occurance of sep, and another substring for all the content afterwards.

Example​

A Basic Partition
local s = "hello world, what's up?"
local before, after = string.partition(s, " ")

assert(before == "hello")
assert(after == "world, what's up?")
Partioning From The Right
local s = "hello world, what's up?"
local before, after = string.partition(s, " ", true)

assert(before == "hello world, what's")
assert(after == "up?")

string.endswith​

Checks if a string ends with a suffix.

Parameters​

  1. The string to check.
  2. The substring suffix to check for.

Returns​

A boolean.

Example​

Basic Usage
local s = "hello world"
local r = string.endswith(s, "world") --> true

string.startswith​

Checks if a string starts with a prefix.

Parameters​

  1. The string to check.
  2. The substring prefix to check for.

Returns​

A boolean.

Example​

Basic Usage
local s = "hello world"
local r = string.startswith(s, "hello") --> true

string.find_last_of​

Searches the string for the last character that matches any of the characters specified in its arguments.

Parameters​

  1. The string to search.
  2. A string of characters to match.

Returns​

An integer, or nil if nothing is matched.

Example​

Basic Usage
-- This will find the last occurance of any listed characters.
local s = "he$$o ?$! world$"
local r = string.find_last_of(s, "!$") --> 16

string.find_first_of​

Searches the string for the first character that matches any of the characters specified in its arguments.

Parameters​

  1. The string to search.
  2. A string of characters to match.

Returns​

An integer, or nil if nothing is matched.

Example​

Basic Usage
-- This will find the first occurance of any listed characters.
local s = "he$$o ?$! world$"
local r = string.find_first_of(s, "!$") --> 3

string.iswhitespace​

Checks if this string is entirely composed of whitespace characters.

Paramaters​

  1. The string to check.

Returns​

A boolean.

Example​

Basic Usage
local s = "    \t \v \f     \t\t\t\t"
local r = string.iswhitespace(s) --> true

string.find_last_not_of​

Searches the string for the last character that does not match any of the characters specified in its arguments.

Parameters​

  1. The string to search.
  2. A string of characters to match.

Returns​

An integer, or nil if nothing is matched.

Example​

Basic Usage
-- This will find the last non-occurance of any listed characters.
local s = "he$$o ?$! world$"
local r = string.find_last_not_of(s, "!$") --> 15

string.find_first_not_of​

Searches the string for the first character that does not match any of the characters specified in its arguments.

Parameters​

  1. The string to search.
  2. A string of characters to match.

Returns​

An integer, or nil if nothing is matched.

Example​

Basic Usage
-- This will find the first non-occurance of any listed characters.
local s = "he$$o ?$! world$"
local r = string.find_first_not_of(s, "!$") --> 1

Modified Functions​

string.upper​

This function now takes a second parameter that specifies which index to capitalize.

Example​

Basic Usage
local s = "hello"assert(s:upper(1) == "Hello")

string.lower​

This function now takes a second parameter that specifies which index to make lowercase.

Example​

Basic Usage
local s = "HELLO"assert(s:lower(1) == "hELLO")