42 lines
1.2 KiB
Text
42 lines
1.2 KiB
Text
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--| Turn a `Map k (Optional v)` into a `Map k v` by dropping all
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-- entries with value `None`.
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let List/concatMap =
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missing
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sha256:3b2167061d11fda1e4f6de0522cbe83e0d5ac4ef5ddf6bb0b2064470c5d3fb64
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? ../List/concatMap.dhall
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let Map/Entry =
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missing
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sha256:f334283bdd9cd88e6ea510ca914bc221fc2dab5fb424d24514b2e0df600d5346
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? ./Entry.dhall
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let Map/Type =
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missing
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sha256:210c7a9eba71efbb0f7a66b3dcf8b9d3976ffc2bc0e907aadfb6aa29c333e8ed
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? ./Type.dhall
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let unpackOptionals
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: ∀(k : Type) → ∀(v : Type) → Map/Type k (Optional v) → Map/Type k v
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= λ(k : Type) →
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λ(v : Type) →
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List/concatMap
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(Map/Entry k (Optional v))
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(Map/Entry k v)
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( λ(e : Map/Entry k (Optional v)) →
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merge
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{ None = [] : Map/Type k v
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, Some = λ(v : v) → [ { mapKey = e.mapKey, mapValue = v } ]
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}
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e.mapValue
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)
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let example0 =
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assert
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: unpackOptionals
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Text
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Text
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(toMap { foo = Some "bar", baz = None Text })
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≡ toMap { foo = "bar" }
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in unpackOptionals
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