virgil

Strings

Virgil III has very basic support for strings; they are represented as mutable arrays of bytes. String literals are translated into arrays of bytes and usable as arrays of bytes in your program. In fact, the string type is just an alias for Array<byte>. The two types are completely interchangeable.

var a: string = "";
var b: string = "The quick brown fox";
var c: string = null;

Escapes

Strings can use the ‘' character to escape some characters, such as carriage return, newline, tab, and quotes within strings.

// newline, tab, carriage-return, backslash, single-quote and double-quote
var a: string = "\n\t\r\\\'\"";

Hex byte values

Strings can use embedded hexadecimal byte values escaped with \xXX.

// hexadecimal bytes can be used in string literals
var a: string = "\x00\x0A\xF1\xDD\xFF";

Strings are arrays

Remember that strings are simply arrays of bytes. The individual bytes can be accessed just as a normal byte array, as can the length. Out of bounds accesses cause exceptions as well.

var a: string = "abcvar";
var b: byte = a[0]; // strings are just arrays of bytes

def main() {
    var a = "abcvar";
    var x = a[11]; // produces !BoundsCheckException
}

Forward compatibility

This is not the final design for strings. In the future, Virgil III will support immutable arrays, and the string type will be an alias for an immutable array of bytes. Generally speaking, it’s a bad idea to modify the contents of a string. Don’t do it!