Expressions and operators

An expression is a piece of code that produces a value. Literals such as 4, true, and "Pop" are expressions. Names, function calls, and operations are expressions too.

local base = 20
local result = base * 2 + 2

Pop evaluates multiplication before addition, so result is 42. Parentheses can make a different order explicit:

local result = base * (2 + 2)

Arithmetic

Pop provides the familiar numeric operators:

Operator	Meaning
+	addition
-	subtraction
*	multiplication
/	division
%	integer remainder

Both operands must have the same numeric type. Pop does not silently mix, for example, Int32 and Int64. The % operator is available only for integers.

Integer arithmetic is checked. Overflow, division by zero, and the signed minimum divided by -1 stop execution with a trap instead of producing a wrapped value.

The unary - operator negates a signed number. Unsigned integers cannot be negated.

Comparing values

Comparison operators produce a Boolean:

local same = left == right
local different = left ~= right
local smaller = left < right
local greater = left > right

== tests equality and ~= tests inequality. Ordering with < and > is available for two numbers of the same type.

Equality is deliberately type-directed. It works for nil, booleans, integers, strings, and supported composite values. Arrays, tables, and functions do not have general value equality in this release. Classes compare their identity: two names are equal when they refer to the same object.

Boolean logic

Use and, or, and not with Boolean values:

local canEnter = hasTicket and not banned
local needsHelp = lost or injured

and stops as soon as its left side is false, because the complete expression cannot become true. or stops as soon as its left side is true. This short-circuit behavior is useful when the right side should run only when needed.

Strings and conversion

The arithmetic + operator does not join strings in 0.1.0-rc.2. The Standard foundation also does not yet expose general string formatting or conversion functions. print can print either a String or an Int, one value and one line at a time.