Primitives

Primitives are the built-in object types that all other objects are composed from. They can be created through literals, atomic expressions that evaluate to a value.

All primitive values in Magpie are immutable. That means that once created, they cannot be changed. 3 is always 3 and "hi" is always "hi".

Booleans

A boolean value represents truth or falsehood. There are two boolean literals, true and false. Its class is Bool.

Numbers

Magpie has two numeric types, integers and floating-point. Number literals look like you expect:

// Ints
0
1234
-5678

// Floats
3.14159
1.0
-12.34

Integers and floating-point numbers are instances of different classes (Int and Float respectively) and there are no implicit conversions in Magpie. This means that if you have a method that expects a Float, then passing 1 won't work. You'll need to pass 1.0.

In practice, this is rarely an issue. Most arithmetic operations have specializations for both kinds of numbers and will work fine regardless of what you pass. In cases where mixed argument types are passed, then the result will be a float.

If you want to write code that works generically with either kind of number, then you want the Num class. Both Int and Float inherit from that, so a method specialized to Num will accept either type.

Strings

String literals are surrounded in double quotes:

"hi there"

A couple of escape characters are supported:

"\n" // Newline.
"\"" // A double quote character.
"\\" // A backslash.

Their class is String.

Characters

Characters are instance of the Char class and represent the individual Unicode code points that make up strings. When you index into a string or iterate over it, character objects will be returned. They also have a literal form, which is the character surrounded by single quotes:

'A'
'!'

There will also be escape sequences for characters, but they haven't been implemented yet.

Nothing

Magpie has a special primitive value nothing, which is the only value of the class Nothing. (Note the difference in case.) It functions a bit like void in some languages: it indicates the absence of a value. An if expression with no else block whose condition is false evaluates to nothing. Likewise, a method like print() that doesn't return anything actually returns nothing.

It's also similar to null in some ways, but it doesn't have the problems that null has in most other languages. It's rare that you'll actually need to write nothing in code since it can usually be inferred from context but it's there if you need it.

Since nothing is in its own class, that means that a method that is specialized to another class won't receive nothing instead. In Magpie, you never need to do this:

def length(string is String)
    // Make sure we got a string.
    if string == nothing then return 0

    string count
end

If your method expects a string, you'll get a string, not a string-or-maybe-nothing.