diff options
| -rw-r--r-- | src/gleam/dynamic.gleam | 27 | ||||
| -rw-r--r-- | test/gleam/dynamic_test.gleam | 20 |
2 files changed, 47 insertions, 0 deletions
diff --git a/src/gleam/dynamic.gleam b/src/gleam/dynamic.gleam index f84db90..8cdebcd 100644 --- a/src/gleam/dynamic.gleam +++ b/src/gleam/dynamic.gleam @@ -987,6 +987,33 @@ pub fn any(of decoders: List(Decoder(t))) -> Decoder(t) { } } +/// Decode 1 values from a `Dynamic` value. +/// +/// ## Examples +/// +/// ```gleam +/// > from(#(1, 2.0, "3")) +/// > |> decode1(MyRecord, element(0, int)) +/// Ok(MyRecord(1)) +/// ``` +/// +/// ```gleam +/// > from(#("", "", "")) +/// > |> decode1(MyRecord, element(0, int)) +/// Error([ +/// DecodeError(expected: "Int", found: "String", path: ["0"]), +/// ]) +/// ``` +/// +pub fn decode1(constructor: fn(t1) -> t, t1: Decoder(t1)) -> Decoder(t) { + fn(value) { + case t1(value) { + Ok(a) -> Ok(constructor(a)) + a -> Error(all_errors(a)) + } + } +} + /// Decode 2 values from a `Dynamic` value. /// /// ## Examples diff --git a/test/gleam/dynamic_test.gleam b/test/gleam/dynamic_test.gleam index 9d1aeba..0caf8c5 100644 --- a/test/gleam/dynamic_test.gleam +++ b/test/gleam/dynamic_test.gleam @@ -838,6 +838,26 @@ pub fn any_test() { |> should.equal(Error([DecodeError("another type", "String", path: [])])) } +type One(a) { + One(a) +} + +pub fn decode1_test() { + let decoder = dynamic.decode1(One, dynamic.element(0, dynamic.int)) + + #(1) + |> dynamic.from + |> decoder + |> should.equal(Ok(One(1))) + + #(1.3) + |> dynamic.from + |> decoder + |> should.equal(Error([ + DecodeError(expected: "Int", found: "Float", path: ["0"]), + ])) +} + type Two(a, b) { Two(a, b) } |