string

The string module is auto-imported — no import statement needed.

Functions

Function	Signature	Description
trim	(String) -> String	Remove leading and trailing whitespace.
split	(String, String) -> List[String]	Split a string by separator into a list of substrings.
join	(List[String], String) -> String	Join a list of strings with a separator.
len	(String) -> Int	Return the number of characters in a string.
contains	(String, String) -> Bool	Check if a string contains a substring.
starts_with	(String, String) -> Bool	Check if a string starts with a prefix.
ends_with	(String, String) -> Bool	Check if a string ends with a suffix.
slice	(String, Int, Int) -> String	Extract a substring by start and optional end index.
pad_start	(String, Int, String) -> String	Pad a string on the left to reach a target length.
to_bytes	(String) -> List[Int]	Convert a string to a list of UTF-8 byte values.
capitalize	(String) -> String	Capitalize the first character of a string.
to_upper	(String) -> String	Convert all characters to uppercase.
to_lower	(String) -> String	Convert all characters to lowercase.
replace	(String, String, String) -> String	Replace all occurrences of a substring.
get	(String, Int) -> Option[String]	Get the character at a given index, or none if out of bounds.
lines	(String) -> List[String]	Split a string into lines.
chars	(String) -> List[String]	Split a string into individual characters.
index_of	(String, String) -> Option[Int]	Find the first index of a substring, or none if not found.
repeat	(String, Int) -> String	Repeat a string n times.
from_bytes	(List[Int]) -> String	Create a string from a list of UTF-8 byte values.
is_digit	(String) -> Bool	Check if all characters are ASCII digits.
is_alpha	(String) -> Bool	Check if all characters are alphabetic.
is_alphanumeric	(String) -> Bool	Check if all characters are alphanumeric.
is_whitespace	(String) -> Bool	Check if all characters are whitespace.
is_upper	(String) -> Bool	Check if all characters in the string are uppercase.
is_lower	(String) -> Bool	Check if all characters in the string are lowercase.
codepoint	(String) -> Option[Int]	Return the Unicode codepoint of the first character, or none for empty string.
from_codepoint	(Int) -> String	Create a single-character string from a Unicode codepoint.
pad_end	(String, Int, String) -> String	Pad a string on the right to reach a target length.
trim_start	(String) -> String	Remove leading whitespace.
trim_end	(String) -> String	Remove trailing whitespace.
count	(String, String) -> Int	Count occurrences of a substring.
is_empty	(String) -> Bool	Check if a string is empty.
reverse	(String) -> String	Reverse the characters in a string.
strip_prefix	(String, String) -> Option[String]	Remove a prefix if present, returning none if not found.
strip_suffix	(String, String) -> Option[String]	Remove a suffix if present, returning none if not found.
replace_first	(String, String, String) -> String	Replace the first occurrence of a substring.
last_index_of	(String, String) -> Option[Int]	Find the last index of a substring, or none if not found.
first	(String) -> Option[String]	Get the first character of a string.
last	(String) -> Option[String]	Get the last character of a string.
take	(String, Int) -> String	Take the first N characters.
take_end	(String, Int) -> String	Take the last N characters.
drop	(String, Int) -> String	Drop the first N characters.
drop_end	(String, Int) -> String	Drop the last N characters.

Reference

string.trim(s: String) -> String

Remove leading and trailing whitespace.

string.trim("  hello  ") // => "hello"

string.split(s: String, sep: String) -> List[String]

Split a string by separator into a list of substrings.

string.split("a,b,c", ",") // => ["a", "b", "c"]

string.join(list: List[String], sep: String) -> String

Join a list of strings with a separator.

string.join(["a", "b", "c"], "-") // => "a-b-c"

string.len(s: String) -> Int

Return the number of characters in a string.

string.len("hello") // => 5

string.contains(s: String, sub: String) -> Bool

Check if a string contains a substring.

string.contains("hello world", "world") // => true

string.starts_with(s: String, prefix: String) -> Bool

Check if a string starts with a prefix.

string.starts_with("hello", "hel") // => true

string.ends_with(s: String, suffix: String) -> Bool

Check if a string ends with a suffix.

string.ends_with("hello", "llo") // => true

string.slice(s: String, start: Int, end: Int) -> String

Extract a substring by start and optional end index.

string.slice("hello", 1, 4) // => "ell"

string.pad_start(s: String, n: Int, ch: String) -> String

Pad a string on the left to reach a target length.

string.pad_start("42", 5, "0") // => "00042"

string.to_bytes(s: String) -> List[Int]

Convert a string to a list of UTF-8 byte values.

string.to_bytes("Hi") // => [72, 105]

string.capitalize(s: String) -> String

Capitalize the first character of a string.

string.capitalize("hello") // => "Hello"

string.to_upper(s: String) -> String

Convert all characters to uppercase.

string.to_upper("hello") // => "HELLO"

string.to_lower(s: String) -> String

Convert all characters to lowercase.

string.to_lower("HELLO") // => "hello"

string.replace(s: String, from: String, to: String) -> String

Replace all occurrences of a substring.

string.replace("aabbcc", "bb", "XX") // => "aaXXcc"

string.get(s: String, i: Int) -> Option[String]

Get the character at a given index, or none if out of bounds.

string.char_at("hello", 1) // => some("e")

string.lines(s: String) -> List[String]

Split a string into lines.

string.lines("a\nb\nc") // => ["a", "b", "c"]

string.chars(s: String) -> List[String]

Split a string into individual characters.

string.chars("abc") // => ["a", "b", "c"]

string.index_of(s: String, needle: String) -> Option[Int]

Find the first index of a substring, or none if not found.

string.index_of("hello", "ll") // => some(2)

string.repeat(s: String, n: Int) -> String

Repeat a string n times.

string.repeat("ab", 3) // => "ababab"

string.from_bytes(bytes: List[Int]) -> String

Create a string from a list of UTF-8 byte values.

string.from_bytes([72, 105]) // => "Hi"

string.is_digit(s: String) -> Bool

Check if all characters are ASCII digits.

string.is_digit("123") // => true

string.is_alpha(s: String) -> Bool

Check if all characters are alphabetic.

string.is_alpha("abc") // => true

string.is_alphanumeric(s: String) -> Bool

Check if all characters are alphanumeric.

string.is_alphanumeric("abc123") // => true

string.is_whitespace(s: String) -> Bool

Check if all characters are whitespace.

string.is_whitespace("  ") // => true

string.is_upper(s: String) -> Bool

Check if all characters in the string are uppercase.

string.is_upper("ABC") // => true

string.is_lower(s: String) -> Bool

Check if all characters in the string are lowercase.

string.is_lower("abc") // => true

string.codepoint(s: String) -> Option[Int]

Return the Unicode codepoint of the first character, or none for empty string.

string.codepoint("A") // => some(65)

string.from_codepoint(n: Int) -> String

Create a single-character string from a Unicode codepoint.

string.from_codepoint(65) // => "A"

string.pad_end(s: String, n: Int, ch: String) -> String

Pad a string on the right to reach a target length.

string.pad_end("hi", 5, ".") // => "hi..."

string.trim_start(s: String) -> String

Remove leading whitespace.

string.trim_start("  hello") // => "hello"

string.trim_end(s: String) -> String

Remove trailing whitespace.

string.trim_end("hello  ") // => "hello"

string.count(s: String, sub: String) -> Int

Count occurrences of a substring.

string.count("banana", "an") // => 2

string.is_empty(s: String) -> Bool

Check if a string is empty.

string.is_empty("") // => true

string.reverse(s: String) -> String

Reverse the characters in a string.

string.reverse("hello") // => "olleh"

string.strip_prefix(s: String, prefix: String) -> Option[String]

Remove a prefix if present, returning none if not found.

string.strip_prefix("hello", "hel") // => some("lo")

string.strip_suffix(s: String, suffix: String) -> Option[String]

Remove a suffix if present, returning none if not found.

string.strip_suffix("hello", "llo") // => some("he")

string.replace_first(s: String, from: String, to: String) -> String

Replace the first occurrence of a substring.

string.replace_first("aabaa", "a", "X") // => "Xabaa"

string.last_index_of(s: String, needle: String) -> Option[Int]

Find the last index of a substring, or none if not found.

string.last_index_of("abcabc", "bc") // => some(4)

string.first(s: String) -> Option[String]

Get the first character of a string.

string.first("hello") // => some("h")

string.last(s: String) -> Option[String]

Get the last character of a string.

string.last("hello") // => some("o")

string.take(s: String, n: Int) -> String

Take the first N characters.

string.take("hello", 3) // => "hel"

string.take_end(s: String, n: Int) -> String

Take the last N characters.

string.take_end("hello", 3) // => "llo"

string.drop(s: String, n: Int) -> String

Drop the first N characters.

string.drop("hello", 2) // => "llo"

string.drop_end(s: String, n: Int) -> String

Drop the last N characters.

string.drop_end("hello", 2) // => "hel"