Expressions in Dinky are anything that returns a single value. They can be as simple as 2 or a+100 or more complex operations like a+((5/2)*10) and a ? 10 : 20.

Expressions can be assigned to variables or passed to functions.

local a = 67*6
setScore(hits*100)

Expressions perform what is called const folding. If you write 10+9 the compiler will emit 19. You can do complex math operations at run-time without fear of performance issues. If you do a+9*10 the compile will generate a+90.

+, -, *, /, %

Math operators

~, !

Unary operators

==, !=, <, >, <=, >=

Comparison operators

|, &

Bit-wise

&&, ||

Logical operators

if (foo && bar) {
    ...
}

Logical comparisons perform what is called "short circuiting". If a == 0 and b == 1, doing if (a && b) will only compare a before skipping the rest of the comparison. This is important when doing if (funcA() && funcB()) and running funcA() and funcB() is time consuming.

+=, -=, *=, /=, |=, &=, ++, --

Assignment operators

local v = 10
v += 2
v -= 1

v++
v--
++v
--v

The ++ and -- operator can be applied before or after evaluating the variable. If you do

local v = 6
if (++v == 7) { ... }   // true
if (v++ == 7) { ... }   // true
if (v == 8) { ... }     // true

a?b:c | a?:c

Trinary operators

If a is true, then b is returned, otherwise c.

local found = (name == "Delores" ? true : false)

Dinky also supports a special version that return a if a is true, otherwise c. This can be useful in cases like bigFunc() ?: 0. If bugFunc() is computationally expensive, you don't want to execute it twice.

actor = findActor(point(x,y))?:ransome

Dinky Expressions