Stdlib/std.str/string

string

struct string

A UTF-8–encode string.

In Navi, strings are immutable.

Examples

let s = "Hello, world!";
assert_eq s.len(), 13;

let s = "Hello 🌍!";
assert_eq s.len(), 11;

Methods

pub fn bytes(self): Bytes

Return the std.io.Bytes of the string.

Example

let s = "Hello, world!";
let buf = s.bytes();
// buf is a Bytes object, value is [72, 101, 108, 108, 111, 44, 32, 119, 111, 114, 108, 100, 33]

let s = "👋🏻 你好";
s.bytes().len(); // 15

pub fn is_empty(self): bool

Return true if string is empty.

Example

assert_eq "".is_empty(), true;
assert_eq "hello".is_empty(), false;

pub fn to_string(self): string

Implement ToString interface

pub fn error(self): string

Implement error interface

pub fn chars(self): Chars

Returns an iterator over the chars of a string.

pub fn strip_suffix(self, suffix: string): string

Returns a new string with the suffix removed, in case sensitive.

Example

let s = "Hello, world!".strip_suffix("!");
// "Hello, world"

pub fn strip_prefix(self, prefix: string): string

Returns a new string with the prefix removed, in case sensitive.

Example

let s = "Hello, world!".strip_prefix("H");
// "ello, world!"

let s = "Hello, world!".strip_prefix("h");
// "Hello, world!"

pub fn parse_float(self): float?

Parse a string to a float?.

If the string is a valid float, return float value, else return nil.

Example

let n = "123.456".parse_float();
assert_eq n, 123.456;

let n = "123".parse_float();
assert_eq n, 123.0;

let n = "123.456.789".parse_float();
assert_eq n, nil;

let n = "abc".parse_float();
assert_eq n, nil;

let n = "123abc".parse_float();
assert_eq n, nil;

pub fn parse_int(self): int?

Parse a string to a int?.

If the string is a valid int, return int value, else return nil.

Example

let n = "123".parse_int();
assert_eq n, 123;

let n = "123.456".parse_int();
assert_eq n, nil;

let n = "abc".parse_int();
assert_eq n, nil;

let n = "123abc".parse_int();
assert_eq n, nil;

pub fn repeat(self, count: int): string

Return a new string with repeated copies of the string.

Example

let s = "-".repeat(5);
// "-----"

pub fn trim_end(self): string

Trim whitespace from the end of a string.

Example

let s = "  Hello, world!  ";
s.trim_end(); // "  Hello, world!"

pub fn trim_start(self): string

Trim whitespace from the start of a string.

Example

let s = "  Hello, world!  ";
s.trim_start(); // "Hello, world!  "

pub fn trim(self): string

Trim whitespace from the start and end of a string.

Example

let s = "  Hello, world!  ";
s.trim(); // "Hello, world!"

pub fn split(self, sep: string): [string]

Split a string into a list of strings.

Example

let s = "Hello, world!";
s.split(", "); // ["Hello", "world!"]
s.split(""); // ["H", "e", "l", "l", "o", ",", " ", "w", "o", "r", "l", "d", "!"]

pub fn get(self, index: int): char?

Get a char from a string by index(0 based).

Example

let s = "Hello, world!";
assert_eq s.get(0), 'H';
assert_eq s.get(7), 'w';
assert_eq s.get(12), '!';

pub fn ends_with(self, substr: string): bool

Check if string ends with a substring, in case sensitive.

Example

let s = "Hello, world!";
s.ends_with("world!"); // true
s.ends_with("World!"); // false

let s = "你好，世界";
s.ends_with("界"); // true

pub fn starts_with(self, substr: string): bool

Check if string starts with a substring, in case sensitive.

Example

let s = "Hello, world!";
s.starts_with("Hello"); // true
s.starts_with("hello"); // false

let s = "你好，世界！";
s.starts_with("你"); // true

pub fn replace(self, from: string, to: string): string

Replace all matches substring with another string.

Example

let s = "Hello, world!";
s.replace("world", "foo"); // "Hello, foo!"

let s = "foo/bar/dar";
s.replace("/", "-"); // "foo-bar-dar"

pub fn slice(self, start: int, end: int): string

Get a slice from a string.

The start and end are the start and end index of the substring (zero based in bytes).

Example

let s = "hello world.";
assert_eq s.slice(0, 5), "hello";
assert_eq s.slice(6, 11), "world";

assert_eq s.slice(0, 0), "";

let s = "hello 你好";
assert_eq s.slice(0, 5).len(), "hello".len();
assert_eq s.slice(6, 12), "你好";

pub fn to_uppercase(self): string

Convert a string to uppercase.

Example

let s = "Hello, world!";

s.to_uppercase(); // "HELLO, WORLD!"

pub fn to_lowercase(self): string

Convert a string to lowercase.

Example

let s = "Hello, world!";
s.to_lowercase(); // "hello, world!"

pub fn find(self, substr: string, from: int? = nil): int?

Find the first index of a substring in a string.

Return the index of the first occurrence of the substring in the string, or nil if not found.

Example

let s = "Hello, world!";
s.find("world"); // 7
s.find("foo"); // nil

pub fn contains(self, substr: string): bool

Check if a string contains a substring.

Example

let s = "Hello, world!";
s.contains("world"); // true
s.contains("foo"); // false

pub fn count(self): int

Return the chars length of the string.

See also: s.len() to get bytes length.

Example

let s = "👋🏻 你好";
assert_eq s.count(), 5;

pub fn len(self): int

Return the bytes length of the string.

See also: s.count() to get chars length.

Example

let s = "Hello, world!";
s.len(); // 13

let s = "";
s.len(); // 0

let s = "👋🏻 你好";
assert_eq s.len(), 15;

pub fn operator+:2(self, b: string): string

pub fn operator<=:2(self, b: string): bool

pub fn operator<:2(self, b: string): bool

pub fn operator>=:2(self, b: string): bool

pub fn operator>:2(self, b: string): bool

pub fn operator!=:2(self, b: string): bool

pub fn operator==:2(self, b: string): bool

pub fn equal_ignore_ascii_case(self, b: string): bool

Checks that two strings are an ASCII case-insensitive match.

pub fn from_utf8(data: Bytes): string throws Utf8Error

Converts a bytes to a string.

Errors

throws Utf8Error if the bytes is not UTF-8.