Toy/_getting_started/quick-start-guide.md

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page	Toy v2 Quick-Start Guide	1

Toy v2 Quick-Start Guide

To help you start using Toy as fast as possible, here are the most useful elements of the language. Not everything available is listed, but this should let you start coding right away.

Keyword 'print'

The print keyword takes one value as a parameter, which is sent to stdout by default.

The value can be redirected elsewhere using the debug C API.

print "Hello World!";

Keyword 'assert'

The assert keyword takes two values as parameters, separated by a comma. If the first value is null or false, the second parameter is sent to stderr by default. Otherwise, this statement is ignored.

The second value, which is replaced by a default error message if omitted, can be redirected elsewhere using the debug C API.

The generation of assert statements can be disabled using the parser C API.

assert 1 < 2;

assert null, "Hello world!";

Variables and Types

Values can be stored in variables, by specifying a name with the var keyword. The name can also be declared with a type, which restricts what kind of value can be stored in the name. Types are optional, and defaults to any when not used.

var answer = 42;

var question: string = "How many roads must a man walk down?";

To make a variable unchangeable after declaration, you can add the const keyword after the type.

var quote: string const = "War. War never changes.";

The usable types are as follows:

type	name	description
bool	boolean	Either true or false.
int	integer	Any whole number, representable by a signed 32-bit integer.
float	float	A decimal number, represented by 32-bits for floating-point arithmetic.
string	string	A piece of text, supports UTF-8.
array	array	A series of values stored in sequential memory.
table	table	A series key-value pairs stored in such a way that allows for fast lookups. Booleans, functions and opaques can't be used as keys.
function	function	A chunk of code to be called. It can take multiple parameters, and provide multiple return values. Unlike other variables, functions are declared with the fn keyword.
opaque	opaque	The contents of this value is unusable in the script, but can be passed from one API to another.
any	any	The default type used when none is specified. This type can hold any value.

Note: Functions and opaques are not yet implemented at the time of writing.

Control Flow

Performing different actions, or repeating an action multiple times, is essential for any general purpose language.

Choosing between two options can be done with the if-then-else else statement. If the condition is 'truthy', the 'then-branch' will be executed. If the condition is not truthy, the optional 'else-branch' is executed instead.

var answer = 42;

if (answer < 56) {
    print "Success";
}
else {
    print "Something's fishy here...";
}

var challenge = "hard";

if (challenge == "hard") {
    print "I choose to build a scripting language, not because it's easy, but because it's hard!";
}

//the else-branch is optional

To repeat a certain action, use the while-then loop, which repeats the body as long as the condition is true at the beginning of each loop.

var loops = 0;

while (loops++ < 8) {
    print "These episodes are endless.";
}

To break out of a loop, you can use the break keyword. Alternatively, to restart the loop early, use the continue keyword.

var loops = 0;

while (true) {
    if (++loops < 15532) {
        continue;
    }

    break; //poor yuki ;_;
}

Functions

Watch this space.

External Libraries and Extending Toy

Watch this space.

Reserved Keywords & Operators

Watch this space.