Strings

Strings in Zephyr are immutable, UTF-8 encoded sequences of characters.

String Literals

Strings are defined using double quotes ".

let s = "Hello, Zephyr";

String Interpolation

Zephyr supports string interpolation via f-strings. Expressions within curly braces {} are evaluated and converted to their string representation at runtime.

let name = "Alice";
let greeting = f"Hello, {name}!"; // "Hello, Alice!"

Concatenation

Use the + operator to join two or more strings together.

let a = "Hello";
let b = "World";
let c = a + ", " + b + "!";
print(c);   // Hello, World!

Expressions of any type are automatically converted to their string representation:

let x = 3.14;
print(f"pi ≈ {x}");   // pi ≈ 3.14

std/string module

import "std/string";

Function	Description
split(s, sep)	Split string by separator → array
trim(s)	Remove leading/trailing whitespace
replace(s, from, to)	Replace all occurrences
to_upper(s)	Uppercase
to_lower(s)	Lowercase
starts_with(s, prefix)	bool
ends_with(s, suffix)	bool
contains(s, sub)	bool
len(s)	Length in bytes

import "std/string";

let s = "  Hello, World!  ";
print(trim(s));                    // Hello, World!
print(to_upper("hello"));          // HELLO
print(split("a,b,c", ","));        // ["a", "b", "c"]
print(replace("foo bar", "bar", "baz")); // foo baz

Built-in string functions

These are available without any import as globally accessible built-ins:

print(len("hello"));          // 5
print(str(42));               // "42"
print(contains("hello", "ell"));     // true
print(starts_with("hello", "he"));   // true
print(ends_with("hello", "lo"));     // true