String

string is the built-in type for textual values. It is a reference type whose lifetime is managed by the runtime under Cloth’s hierarchical ownership model.

Literals

String literals are written in double quotes:

let greeting = "Hello, World!";

A string literal has type string. There is no distinct character-array type for source-level string data — every literal is a string.

Concatenation

Strings can be concatenated with the + operator. The result is a new string whose contents are the left operand followed by the right operand.

The standard library exposes the same operation as a static function on cloth.lang.String:

import cloth.lang.String;

let full = String.concat("Hello, ", "World!");

String.concat is the lower-level form. Its implementation uses strlen, calloc, and strcat from the C runtime through the @Extern mechanism described in Annotations.

Output

cloth.io.Out provides a println overload for string:

import cloth.io.Out::{ println };

println("Hello, World!");

A println() call with no arguments prints an empty line.

Nullable strings

A string value is non-null by default. To allow null, write the type as string!:

public class (string! message) {
    public const string! message { public getter; };
}

The ! suffix marks the type as nullable. See Nullable Types for the full rules.

Comparison

The equality operators == and != are defined on string values and compare the textual content of the two operands.

Use in declarations

string may appear wherever any other type may appear: in fields, parameters, variable bindings, and return types.

public func greet(string name): string {
    return "Hello, " + name;
}