/Prelude-v23.0.0/Text/defaultMap.dhall

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Transform the value in an Optional into Text, defaulting None to ""

Examples

defaultMap Natural Natural/show (Some 0) ≡ "0"
defaultMap Natural Natural/show (None Natural) ≡ ""

Source

--| Transform the value in an `Optional` into `Text`, defaulting `None` to `""`
let defaultMap
: ∀(a : Type) → (a → Text) → Optional a → Text
= λ(a : Type) →
λ(f : a → Text) →
λ(o : Optional a) →
merge { Some = f, None = "" } o

let example0 = assert : defaultMap Natural Natural/show (Some 0) ≡ "0"

let example1 = assert : defaultMap Natural Natural/show (None Natural) ≡ ""

in defaultMap