Strings

String type

let greeting: string = "Hello, world!";

In t1/t2, string is an owned, heap-allocated UTF-8 sequence.

String interpolation

let name = "tape";
let version = 2;
let msg = "Welcome to {name} v{version}!";

Expressions inside {} are evaluated and converted to their string representation.

Escape sequences

Use \{ and \} when you need literal braces alongside interpolation:

let json = "\{\"name\": \"{name}\", \"age\": {age}\}";
// Output: {"name": "tape", "age": 25}

Triple-quoted strings

Triple-quoted strings can span multiple lines and contain " without escaping:

let html = """
<div class="container">
    <p>Hello, {name}!</p>
</div>
""";

Escape sequences and interpolation are active inside triple-quoted strings.

Raw strings

Prefix triple quotes with r to disable all escape sequences and interpolation:

let json = r"""{"name": "tape", "version": 2}""";

Raw strings can span multiple lines and contain quotes freely:

let shader = r"""
#version 330 core
void main() {
    gl_Position = vec4(0.0);
}
""";

let config = r"""
{
    "host": "localhost",
    "port": 8080
}
""";

Rules:

• No escape sequences — backslash is a literal character
• No interpolation — braces are literal characters
• Multi-line — newlines are preserved as-is
• Can contain " freely — ends only at """
• Cannot contain the literal sequence """
• Same type as regular strings (string in t1/t2, []const u8 in t0)

Strings in t0

The string type is not available in t0 (no heap). Use byte slices instead:

let msg: []const u8 = "Hello from kernel";

String operations

The str standard library operates on *u8 + length pairs:

import str from "str";

var buf: *u8 = "hello";
str.to_upper(buf, 5);          // in-place case conversion
let n: u32 = str.len(buf);     // null-terminated length
let eq: bool = str.equal(a, a_len, b, b_len);
let idx: i32 = str.index_of(haystack, h_len, needle, n_len);

Available functions: len, char_at, equal, starts_with, ends_with, index_of, contains, copy, concat, to_upper, to_lower, trim_left, trim_right, parse_i64, i64_to_str, i64_to_cstr.

Last modified: 2026-05-29 02:05:16 UTC