Skip to main content

String

The string module provides string manipulation operations for the Crux programming language.

Installation​

use string_upper, string_split from "crux:string";

Methods​

first​

Returns the first character of a string.

let s = "hello"
let c = s.first()  // Result("h")

Returns: Result<String>

Errors: String must have at least one character.

last​

Returns the last character of a string.

let s = "hello"
let c = s.last()  // Result("o")

Returns: Result<String>

Errors: String must have at least one character.

get​

Returns the character at the specified index.

let s = "hello"
let c = s.get(1)  // Result("e")

Parameters:

  • index (Int): The index of the character

Returns: Result<String>

Errors: Index out of bounds, or string must have at least one character.

upper​

Converts a string to uppercase.

let s = "hello"
let upper = s.upper()  // Result("HELLO")

Returns: Result<String>

Errors: Memory allocation failed.

lower​

Converts a string to lowercase.

let s = "HELLO"
let lower = s.lower()  // Result("hello")

Returns: Result<String>

Errors: Memory allocation failed.

strip​

Removes leading and trailing whitespace from a string.

let s = "  hello  "
let trimmed = s.strip()  // Result("hello")

Returns: Result<String>

substring​

Extracts a substring from a string between start and end indices (exclusive).

let s = "hello"
let sub = s.substring(1, 4)  // Result("ell")

Parameters:

  • start (Int): Start index (inclusive)
  • end (Int): End index (exclusive)

Returns: Result<String>

Errors: Indices cannot be negative or out of bounds.

split​

Splits a string into an array of substrings using a delimiter.

let s = "a,b,c"
let parts = s.split(",")  // Result(["a", "b", "c"])

Parameters:

  • delimiter (String): The delimiter to split by

Returns: Result<Array>

Errors: Delimiter cannot be empty.

contains​

Checks if a string contains a substring.

let s = "hello world"
let has_world = s.contains("world")  // Result(true)
let has_foo = s.contains("foo")  // Result(false)

Parameters:

  • substring (String): The substring to search for

Returns: Result<Bool>

Errors: Memory allocation failed.

replace​

Replaces all occurrences of a substring with another string.

let s = "hello world"
let result = s.replace("world", "crux")  // Result("hello crux")

Parameters:

  • target (String): The substring to replace
  • replacement (String): The replacement string

Returns: Result<String>

Errors: Source string must have at least one character, target must have at least one character, or resulting string length exceeds maximum.

starts_with​

Checks if a string starts with a given prefix.

let s = "hello"
let result = s.starts_with("hel")  // Result(true)
let result2 = s.starts_with("world")  // Result(false)

Parameters:

  • prefix (String): The prefix to check

Returns: Result<Bool>

ends_with​

Checks if a string ends with a given suffix.

let s = "hello"
let result = s.ends_with("llo")  // Result(true)
let result2 = s.ends_with("world")  // Result(false)

Parameters:

  • suffix (String): The suffix to check

Returns: Result<Bool>

is_al_num​

Checks if all characters in a string are alphanumeric.

let s = "hello123"
let result = s.is_al_num()  // true
let s2 = "hello!"
let result2 = s2.is_al_num()  // false

Returns: Bool

is_alpha​

Checks if all characters in a string are alphabetic.

let s = "hello"
let result = s.is_alpha()  // true
let s2 = "hello123"
let result2 = s2.is_alpha()  // false

Returns: Bool

is_digit​

Checks if all characters in a string are digits.

let s = "12345"
let result = s.is_digit()  // true
let s2 = "123a"
let result2 = s2.is_digit()  // false

Returns: Bool

is_lower​

Checks if all characters in a string are lowercase.

let s = "hello"
let result = s.is_lower()  // true
let s2 = "Hello"
let result2 = s2.is_lower()  // false

Returns: Bool

is_upper​

Checks if all characters in a string are uppercase.

let s = "HELLO"
let result = s.is_upper()  // true
let s2 = "Hello"
let result2 = s2.is_upper()  // false

Returns: Bool

is_space​

Checks if all characters in a string are whitespace.

let s = "   "
let result = s.is_space()  // true
let s2 = " hello "
let result2 = s2.is_space()  // false

Returns: Bool

is_empty​

Checks if a string is empty.

let s = ""
let result = s.is_empty()  // true
let s2 = "hello"
let result2 = s2.is_empty()  // false

Returns: Bool

concat​

Concatenates two strings together.

let s1 = "hello"
let s2 = " world"
let result = s1.concat(s2)  // Result("hello world")

Parameters:

  • other (String): The string to concatenate

Returns: Result<String>

Errors: Resultant string is too greater than the supported length.