Conditional expressions

An if expression chooses a value without declaring a mutable local first:

local label = if available then "ready" else "missing"

It differs from an if statement in three visible ways:

• each branch is one expression;
• else is required;
• there is no trailing end.

The condition must be Boolean. Both branches must resolve to one identical static type after ordinary permitted conversions.

local count: Int8 = if ready then 1 else 0

This expected Int8 type flows into both integer literals. The compiler rejects unlike branch types instead of inventing a dynamic common type or implicit union:

local invalid = if ready then 1 else "one" -- type error

Lazy evaluation

The condition runs first and exactly one branch runs:

local divisor = 0
local value = if divisor == 0 then 0 else 100 / divisor

The division does not execute when divisor is zero. The same laziness applies during compile-time evaluation and native execution.

Conditional expressions can nest in the else position:

local label = if score > 89 then "excellent" else if score > 59 then "passed" else "retry"

Use statement elseif when each arm contains statements. Pop does not use ?: punctuation.