Curry/Uncurry extension

SandroMaglione · Jul 5, 2021 · e0f5961 · e0f5961
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,6 +1,7 @@
 # v0.0.7
 
 - Added `Compose` and `Compose2`, used to easily compose functions in a chain.
+- Added `curry` and `uncurry` extensions on functions up to 5 parameters.
 
 # v0.0.6 - 29 June 2021
 

diff --git a/example/src/function/curry.dart b/example/src/function/curry.dart
@@ -22,4 +22,13 @@ void main() {
   final divideBy3 = multiplyBy2(3);
   print(divideBy3(10));
   print(sumMultiplyDivideCurry(5)(2)(3)(10));
+
+  /// Using the extension
+  final sumBy2Extension = sum.curry(2);
+  final sumBy10Extension = sum.curry(10);
+  print(sumBy2Extension(10));
+  print(sumBy10Extension(2));
+
+  final fourParamsCurry = sumMultiplyDivide.curry;
+  final fourParamsUncurry = fourParamsCurry.uncurry;
 }
diff --git a/lib/src/function.dart b/lib/src/function.dart
@@ -105,3 +105,94 @@ F Function(A a, B b, C c, D d, E e) uncurry5<A, B, C, D, E, F>(
         function) {
   return (A a, B b, C c, D d, E e) => function(a)(b)(c)(d)(e);
 }
+
+// --- Extensions below 👇 --- //
+
+extension CurryExtension2<Input1, Input2, Output> on Output Function(
+    Input1, Input2) {
+  /// Convert this function from accepting two parameters to a function
+  /// that returns another function both accepting one parameter.
+  ///
+  /// Inverse of `uncurry`.
+  Output Function(Input2) curry(Input1 input1) =>
+      (input2) => this(input1, input2);
+}
+
+extension UncurryExtension2<Input1, Input2, Output> on Output Function(Input2)
+    Function(Input1) {
+  /// Convert a function that returns another function to a single function
+  /// accepting two parameters.
+  ///
+  /// Inverse of `curry`.
+  Output Function(Input1, Input2) uncurry() =>
+      (Input1 input1, Input2 input2) => this(input1)(input2);
+}
+
+extension CurryExtension3<Input1, Input2, Input3, Output> on Output Function(
+    Input1, Input2, Input3) {
+  /// Convert this function from accepting three parameters to a series
+  /// of functions that all accept one parameter.
+  ///
+  /// Inverse of `uncurry`.
+  Output Function(Input3) Function(Input2) curry(Input1 input1) =>
+      (input2) => (input3) => this(input1, input2, input3);
+}
+
+extension UncurryExtension3<Input1, Input2, Input3, Output>
+    on Output Function(Input3) Function(Input2) Function(Input1) {
+  /// Convert a function that returns a series of functions to a single function
+  /// accepting three parameters.
+  ///
+  /// Inverse of `curry`.
+  Output Function(Input1, Input2, Input3) uncurry() =>
+      (Input1 input1, Input2 input2, Input3 input3) =>
+          this(input1)(input2)(input3);
+}
+
+extension CurryExtension4<Input1, Input2, Input3, Input4, Output> on Output
+    Function(Input1, Input2, Input3, Input4) {
+  /// Convert this function from accepting four parameters to a series
+  /// of functions that all accept one parameter.
+  ///
+  /// Inverse of `uncurry`.
+  Output Function(Input4) Function(Input3) Function(Input2) curry(
+          Input1 input1) =>
+      (input2) => (input3) => (input4) => this(input1, input2, input3, input4);
+}
+
+extension UncurryExtension4<Input1, Input2, Input3, Input4, Output>
+    on Output Function(Input4) Function(Input3) Function(Input2) Function(
+        Input1) {
+  /// Convert a function that returns a series of functions to a single function
+  /// accepting four parameters.
+  ///
+  /// Inverse of `curry`.
+  Output Function(Input1, Input2, Input3, Input4) uncurry() =>
+      (Input1 input1, Input2 input2, Input3 input3, Input4 input4) =>
+          this(input1)(input2)(input3)(input4);
+}
+
+extension CurryExtension5<Input1, Input2, Input3, Input4, Input5, Output>
+    on Output Function(Input1, Input2, Input3, Input4, Input5) {
+  /// Convert this function from accepting five parameters to a series
+  /// of functions that all accept one parameter.
+  ///
+  /// Inverse of `uncurry`.
+  Output Function(Input5) Function(Input4) Function(Input3) Function(Input2)
+      curry(Input1 input1) => (input2) => (input3) =>
+          (input4) => (input5) => this(input1, input2, input3, input4, input5);
+}
+
+extension UncurryExtension5<Input1, Input2, Input3, Input4, Input5, Output>
+    on Output Function(Input5) Function(Input4) Function(Input3) Function(
+            Input2)
+        Function(Input1) {
+  /// Convert a function that returns a series of functions to a single function
+  /// accepting five parameters.
+  ///
+  /// Inverse of `curry`.
+  Output Function(Input1, Input2, Input3, Input4, Input5) uncurry() =>
+      (Input1 input1, Input2 input2, Input3 input3, Input4 input4,
+              Input5 input5) =>
+          this(input1)(input2)(input3)(input4)(input5);
+}