if

if is a two-way Boolean conditional.

Syntax

(if ⟨test-expr⟩ ⟨then-expr⟩ ⟨else-expr⟩)

Semantics

• ⟨test-expr⟩ must be a Coalton Boolean.
• if must always have a consequent and alternative.
• For multi-armed conditionals, use cond.
• For structural branching on algebraic data, use match.
• Stylistically, if should only be used for pure computations; side-effectful computations should always use cond.
• It is not recommended to use progn with if.

Example

(if (zero? n) 0 1)