rs-0.18.0 — match, SQLite, and secure tokens#

match replaces long if/elif chains, std.sqlite puts a real SQL database in one file, and std.secrets and std.uuid make tokens, passwords, and IDs that are safe to trust.

match#

family Circle{
    func init(float r){ me.r = r; }
}

func describe(any value) => match (value){
    1, 2, 3 => "small";
    int n if (n > 100) => "big";
    string s => "text " + s;
    Circle c => "a circle";
    _ => "something else";
};

func m{
    out(describe(2), describe(500), describe("hi"), describe(Circle(1.0)));   // small big text hi a circle
}

Arms are tried top to bottom and the first that matches runs. Patterns are literals and lists of them, compared with ==; _; type patterns that bind a name, such as int n, string s, Circle c, or [int, float] n; and guards with if (...). As a statement, a value no arm matches does nothing; as an expression, it raises RangeError naming the value. Unreachable arms, repeated literals, and unknown types are compile errors with their line. Matching is faster than the if/elif chain it replaces. See match.

Compatibility: match is now a keyword, so a variable, function, or parameter named match must be renamed. obj.match as a member still works.

std.sqlite#

takepkg std.sqlite;

func m{
    db = sqlite.open(":memory:");
    db.run("CREATE TABLE people (name TEXT, age INTEGER)", arr());
    db.run("INSERT INTO people VALUES (?, ?)", arr("Ada", 36));
    out(db.query("SELECT name, age FROM people", arr()));   // [{"name": "Ada", "age": 36}]
    db.close();
}

open a file or ":memory:"; run, query, query_one, value, last_id, script, and transaction, which rolls back when its function raises and uses savepoints when nested. Values go in only through ? parameters, so text can never be run as SQL. SQLite itself is built in.

std.secrets and std.uuid#

secrets.token_hex(16), token_url, password(20), int_below, choice, and same use the operating system's secure random source: use them, never std.random, for passwords, keys, and tokens. uuid.v4() makes random IDs and uuid.v7() time-ordered ones, with valid and version to check them.

Validation#

cargo test passes 395 tests on Linux and 393 on Windows. Every push runs them on Windows, macOS, and Linux on x86_64 and ARM64, and runs the static Linux binary inside Alpine, Debian 11, Ubuntu 20.04, Rocky Linux 8, and Amazon Linux 2.