Operators - Jamiras/RATools GitHub Wiki

Arithmetic Operations

left + right - adds numerical values or concatenates string values
left - right - subtracts the second value from the first value
left * right - multiplies numerical values
left / right - divides the first value by the second value, the remainder is discarded
left % right - calculates the remainder when the first value is divided by the second value
left & right - captures the bits that are non-zero in both values (bitwise and)
left ^ right - captures bits differ between values (bitwise xor)
~left - inverts the bits of the value

Comparisons

left == right - the two values are equal
left != right - the two values are not equal
left > right - the first value is greater than the second value
left >= right - the first value is greater than or equal to the second value
left < right - the first value is less than the second value
left <= right - the first value is less than or equal to the second value

left and right must be a memory address, a constant, or a function that evaluates to a memory address or constant

Logical Comparisons

left && right - both conditions must be true
left || right - either condition must be true
!left - the condition must be false

left and right must be comparisons or functions that evaluate to comparisons

Order of Operations

Operators are evaluated in this order (within a level, operators are evaluated left to right as they're read from the expression):

Parentheses
Logical Not
Multiplication, Division, and Modulus
Addition and Subtraction
Bitwise And
Bitwise XOR
Bitwise invert
Comparisons
Logical And
Logical Or

The following statement: N + M * A < B && C > X || D / G * H > Y + Z

Would be interpreted as: (((N + (M * A)) < B) && (C > X)) || (((D / G) * H) > (Y + Z))

It is particularly important to understand how this affects the creation of alt groups:

A == N && B == X || B == Y

Because AND has higher precedence than OR, the interpreter sees:

(A == N && B == X) || (B == Y)

Which is two alt groups and no core group. An achievement must have a core group, so an always_true core group will be generated. You can use parentheses to force a different order. What was intended was:

A == N && (B == X || B == Y)

Here, A == N becomes the core group and there are two alt groups: B == X and B == Y.