String

Utilities for working with strings.

1

from "string" include String

Types

Type declarations included in the String module.

String.Encoding

1
2
3
4
5
6
7

enum Encoding {
  UTF8,
  UTF16_BE,
  UTF16_LE,
  UTF32_BE,
  UTF32_LE,
}

Byte encodings

Values

Functions and constants included in the String module.

String.concat

1

concat : (str1: String, str2: String) => String

Concatenate two strings.

Parameters:

Returns:

Examples:

1

String.concat("Foo", "Bar") == "FooBar"

String.length

1

length : (string: String) => Number

Returns the character length of the input string.

Parameters:

Returns:

Examples:

1

String.length("Hello world") == 11

String.byteLength

1

byteLength : (string: String) => Number

Returns the byte length of the input string.

Parameters:

Returns:

Examples:

1

String.byteLength("🌾") == 4

String.isEmpty

1

isEmpty : (string: String) => Bool

Determines if the string contains no characters.

Parameters:

Returns:

String.indexOf

1

indexOf : (search: String, string: String) => Option<Number>

Finds the first position of a substring in the input string.

Parameters:

Returns:

Examples:

1

String.indexOf("world", "Hello world") == Some(6)

String.lastIndexOf

1

lastIndexOf : (search: String, string: String) => Option<Number>

Finds the last position of a substring in the input string.

Parameters:

Returns:

Examples:

1

String.lastIndexOf("world", "Hello world world") == Some(12)

String.charCodeAt

1

charCodeAt : (position: Number, string: String) => Number

Get the Unicode code point at the position in the input string.

Parameters:

Returns:

Throws:

Failure(String)

• When the position is out of bounds

MalformedUnicode

• When the string is malformed

Examples:

1

String.charCodeAt(5, "Hello world") == 32

String.charAt

1

charAt : (position: Number, string: String) => Char

Get the character at the position in the input string.

Parameters:

Returns:

Throws:

Failure(String)

• When the position is out of bounds

MalformedUnicode

• When the string is malformed

Examples:

1

String.charAt(5, "Hello world") == ' '

String.explode

1

explode : (string: String) => Array<Char>

Split a string into its Unicode characters.

Parameters:

Returns:

Throws:

MalformedUnicode

• When the string is malformed

Examples:

1

String.explode("Hello") == [> 'H', 'e', 'l', 'l', 'o']

String.implode

1

implode : (arr: Array<Char>) => String

Create a string from an array of characters.

Parameters:

Returns:

Examples:

1

String.implode([> 'H', 'e', 'l', 'l', 'o']) == "Hello"

String.reverse

1

reverse : (string: String) => String

Create a string that is the given string reversed.

Parameters:

Returns:

Examples:

1

String.reverse("olleH") == "Hello"

String.split

1

split : (separator: String, string: String) => Array<String>

Split a string by the given separator.

Parameters:

Returns:

Throws:

MalformedUnicode

• When the string is malformed

Examples:

1

String.split(" ", "Hello world") == [> "Hello", "world"]

String.slice

1

slice : (start: Number, ?end: Number, string: String) => String

Get a portion of a string.

Parameters:

Returns:

Throws:

IndexOutOfBounds

• When start is out of bounds
• When end is out of bounds

InvalidArgument(String)

• When the start index is not an integer
• When the to index is not an integer
• When start is greater than end

Examples:

1

String.slice(0, end=5, "Hello world") == "Hello"

1

String.slice(0, "Hello world") == "Hello world"

String.contains

1

contains : (search: String, string: String) => Bool

Check if a string contains a substring.

Parameters:

Returns:

Examples:

1

String.contains("world", "Hello world") == true

String.startsWith

1

startsWith : (search: String, string: String) => Bool

Check if a string begins with another string.

Parameters:

Returns:

Examples:

1

String.startsWith("Hello", "Hello world") == true

String.endsWith

1

endsWith : (search: String, string: String) => Bool

Check if a string ends with another string.

Parameters:

Returns:

Examples:

1

String.endsWith("world", "Hello world") == true

String.replaceFirst

1
2

replaceFirst :
  (searchPattern: String, replacement: String, string: String) => String

Replaces the first appearance of the search pattern in the string with the replacement value.

Parameters:

Returns:

Examples:

1

String.replaceFirst("🌾", "🌎", "Hello 🌾🌾") == "Hello 🌎🌾"

String.replaceLast

1
2

replaceLast :
  (searchPattern: String, replacement: String, string: String) => String

Replaces the last appearance of the search pattern in the string with the replacement value.

Parameters:

Returns:

Examples:

1

String.replaceLast("🌾", "🌎", "Hello 🌾🌾") == "Hello 🌾🌎"

String.replaceAll

1
2

replaceAll :
  (searchPattern: String, replacement: String, string: String) => String

Replaces every appearance of the search pattern in the string with the replacement value.

Parameters:

Returns:

Examples:

1

String.replaceAll("🌾", "🌎", "Hello 🌾🌾") == "Hello 🌎🌎"

String.encodeAt

1
2
3

encodeAt :
  (string: String, encoding: Encoding, dest: Bytes, destPos: Number,
   ?includeBom: Bool) => Bytes

Encodes the given string into a byte sequence at the supplied position using the encoding scheme provided.

Parameters:

Returns:

Throws:

InvalidArgument(String)

• When destPos is not an integer
• When destPos is negative

String.encode

1

encode : (string: String, encoding: Encoding, ?includeBom: Bool) => Bytes

Encodes the given string using the given encoding scheme.

Parameters:

Returns:

String.decodeRange

1
2
3

decodeRange :
  (bytes: Bytes, encoding: Encoding, start: Number, size: Number,
   ?keepBom: Bool) => String

Decodes the given byte sequence of the specified range into a string using the encoding scheme provided.

Parameters:

Returns:

Throws:

InvalidArgument(String)

• When start is not an integer
• When start is negative
• When size is not an integer
• When size is negative

String.decode

1

decode : (bytes: Bytes, encoding: Encoding, ?keepBom: Bool) => String

Decodes the given byte sequence into a string using the given encoding scheme.

Parameters:

Returns:

String.forEachCodePoint

1

forEachCodePoint : (fn: (Number => Void), str: String) => Void

Iterates over Unicode code points in a string.

Parameters:

Examples:

1

String.forEachCodePoint(print, "Hello world")

String.forEachCodePointi

1

forEachCodePointi : (fn: ((Number, Number) => Void), str: String) => Void

Iterates over Unicode code points in a string. This is the same as forEachCodePoint, but provides the code point’s index in the string as the second argument to the iterator function.

Parameters:

Examples:

1

String.forEachCodePointi((codepoint, index) => print((codepoint, index)), "Hello world")

String.trimStart

1

trimStart : (string: String) => String

Trims the beginning of a string—removing any leading whitespace characters.

Parameters:

Returns:

Examples:

1

String.trimStart("   Hello World") == "Hello World"

String.trimEnd

1

trimEnd : (string: String) => String

Trims the end of a string—removing any trailing whitespace characters.

Parameters:

Returns:

Examples:

1

String.trimEnd("Hello World   ") == "Hello World"

String.trim

1

trim : (string: String) => String

Trims a string—removing all leading and trailing whitespace characters.

Parameters:

Returns:

Examples:

1

String.trim("   Hello World   ") == "Hello World"

String.toAsciiLowercase

1

toAsciiLowercase : (string: String) => String

Converts all ASCII uppercase characters in the string to lowercase.

Parameters:

Returns:

Examples:

1

assert String.toAsciiLowercase("aBc123") == "abc123"

String.toAsciiUppercase

1

toAsciiUppercase : (string: String) => String

Converts all ASCII lowercase characters in the string to uppercase.

Parameters:

Returns:

Examples:

1

assert String.toAsciiUppercase("aBc123") == "ABC123"