fix: make use of Empty lazy

Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com>

v2/array/generic/array.go

@@ -323,34 +323,31 @@ func Clone[AS ~[]A, A any](f func(A) A) func(as AS) AS {
 }
 
 func FoldMap[AS ~[]A, A, B any](m M.Monoid[B]) func(func(A) B) func(AS) B {
-	empty := m.Empty()
 	concat := m.Concat
 	return func(f func(A) B) func(AS) B {
 		return func(as AS) B {
 			return array.Reduce(as, func(cur B, a A) B {
 				return concat(cur, f(a))
-			}, empty)
+			}, m.Empty())
 		}
 	}
 }
 
 func FoldMapWithIndex[AS ~[]A, A, B any](m M.Monoid[B]) func(func(int, A) B) func(AS) B {
-	empty := m.Empty()
 	concat := m.Concat
 	return func(f func(int, A) B) func(AS) B {
 		return func(as AS) B {
 			return array.ReduceWithIndex(as, func(idx int, cur B, a A) B {
 				return concat(cur, f(idx, a))
-			}, empty)
+			}, m.Empty())
 		}
 	}
 }
 
 func Fold[AS ~[]A, A any](m M.Monoid[A]) func(AS) A {
-	empty := m.Empty()
 	concat := m.Concat
 	return func(as AS) A {
-		return array.Reduce(as, concat, empty)
+		return array.Reduce(as, concat, m.Empty())
 	}
 }
 

v2/array/sequence.go

@@ -25,7 +25,7 @@ func MonadSequence[HKTA, HKTRA any](
 	fof func(HKTA) HKTRA,
 	m M.Monoid[HKTRA],
 	ma []HKTA) HKTRA {
-	return array.MonadSequence(fof, m.Empty(), m.Concat, ma)
+	return array.MonadSequence(fof, m.Empty, m.Concat, ma)
 }
 
 // Sequence takes an array where elements are HKT<A> (higher kinded type) and,
@@ -67,7 +67,7 @@ func Sequence[HKTA, HKTRA any](
 	fof func(HKTA) HKTRA,
 	m M.Monoid[HKTRA],
 ) func([]HKTA) HKTRA {
-	return array.Sequence[[]HKTA](fof, m.Empty(), m.Concat)
+	return array.Sequence[[]HKTA](fof, m.Empty, m.Concat)
 }
 
 // ArrayOption returns a function to convert a sequence of options into an option of a sequence.

v2/go.mod

@@ -4,7 +4,7 @@ go 1.24
 
 require (
 	github.com/stretchr/testify v1.11.1
-	github.com/urfave/cli/v3 v3.7.0
+	github.com/urfave/cli/v3 v3.8.0
 )
 
 require (

v2/go.sum

@@ -4,10 +4,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
-github.com/urfave/cli/v3 v3.6.2 h1:lQuqiPrZ1cIz8hz+HcrG0TNZFxU70dPZ3Yl+pSrH9A8=
-github.com/urfave/cli/v3 v3.6.2/go.mod h1:ysVLtOEmg2tOy6PknnYVhDoouyC/6N42TMeoMzskhso=
-github.com/urfave/cli/v3 v3.7.0 h1:AGSnbUyjtLiM+WJUb4dzXKldl/gL+F8OwmRDtVr6g2U=
-github.com/urfave/cli/v3 v3.7.0/go.mod h1:ysVLtOEmg2tOy6PknnYVhDoouyC/6N42TMeoMzskhso=
+github.com/urfave/cli/v3 v3.8.0 h1:XqKPrm0q4P0q5JpoclYoCAv0/MIvH/jZ2umzuf8pNTI=
+github.com/urfave/cli/v3 v3.8.0/go.mod h1:ysVLtOEmg2tOy6PknnYVhDoouyC/6N42TMeoMzskhso=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

v2/internal/array/traverse.go

@@ -46,7 +46,7 @@ import (
 //   - Multiple elements: recursively divides and conquers
 func MonadSequenceSegment[HKTB, HKTRB any](
 	fof func(HKTB) HKTRB,
-	empty HKTRB,
+	empty func() HKTRB,
 	concat func(HKTRB, HKTRB) HKTRB,
 	fbs []HKTB,
 	start, end int,
@@ -54,7 +54,7 @@ func MonadSequenceSegment[HKTB, HKTRB any](
 
 	switch end - start {
 	case 0:
-		return empty
+		return empty()
 	case 1:
 		return fof(fbs[start])
 	default:
@@ -254,7 +254,7 @@ HKTAB = HKT<func(A)B>
 */
 func MonadSequence[GA ~[]HKTA, HKTA, HKTRA any](
 	fof func(HKTA) HKTRA,
-	empty HKTRA,
+	empty func() HKTRA,
 	concat func(HKTRA, HKTRA) HKTRA,
 
 	ta GA) HKTRA {
@@ -263,7 +263,7 @@ func MonadSequence[GA ~[]HKTA, HKTA, HKTRA any](
 
 func Sequence[GA ~[]HKTA, HKTA, HKTRA any](
 	fof func(HKTA) HKTRA,
-	empty HKTRA,
+	empty func() HKTRA,
 	concat func(HKTRA, HKTRA) HKTRA,
 ) func(GA) HKTRA {
 

v2/internal/iter/traverse.go

@@ -73,7 +73,7 @@ func MonadTraverse[GA ~func(yield func(A) bool), GB ~func(yield func(B) bool), A
 
 	fof := F.Bind2nd(fmap_b, Of[GB])
 
-	empty := fof_gb(Empty[GB]())
+	empty := F.Nullary2(Empty[GB], fof_gb)
 
 	cb := F.Curry2(Concat[GB])
 	concat_gb := F.Bind2nd(fmap_gb, cb)
@@ -180,7 +180,7 @@ func MonadSequence[GA ~func(yield func(HKTA) bool), HKTA, HKTRA any](
 
 	// convert to an array
 	hktb := ToArray[GA, []HKTA](ta)
-	return INTA.MonadSequenceSegment(fof, m.Empty(), m.Concat, hktb, 0, len(hktb))
+	return INTA.MonadSequenceSegment(fof, m.Empty, m.Concat, hktb, 0, len(hktb))
 }
 
 // MonadTraverseWithIndex traverses an iterator sequence with index tracking, applying an effectful
@@ -223,7 +223,7 @@ func MonadTraverseWithIndex[GA ~func(yield func(A) bool), A, HKTB, HKTRB any](
 
 	// convert to an array
 	hktb := MonadMapToArrayWithIndex[GA, []HKTB](ta, f)
-	return INTA.MonadSequenceSegment(fof, m.Empty(), m.Concat, hktb, 0, len(hktb))
+	return INTA.MonadSequenceSegment(fof, m.Empty, m.Concat, hktb, 0, len(hktb))
 }
 
 // Sequence is the curried version of MonadSequence, returning a function that sequences an iterator of effects.

v2/iterator/iter/compress.go

@@ -34,6 +34,13 @@ import (
 //  3. Filtering to keep only pairs where the boolean (tail) is true
 //  4. Extracting the original values (head) from the filtered pairs
 //
+// Marble Diagram:
+//
+//	Data:      --1--2--3--4--5-->
+//	Selectors: --T--F--T--F--T-->
+//	Compress
+//	Output:    --1-----3-----5-->
+//
 // RxJS Equivalent: Similar to combining [zip] with [filter] - https://rxjs.dev/api/operators/zip
 //
 // Type Parameters:

v2/iterator/iter/cycle.go

@@ -21,6 +21,12 @@ package iter
 // all elements repeatedly. When the end of the input sequence is reached, it starts over
 // from the beginning, continuing this pattern forever.
 //
+// Marble Diagram:
+//
+//	Input:  --1--2--3|
+//	Cycle
+//	Output: --1--2--3--1--2--3--1--2--3--> (infinite)
+//
 // RxJS Equivalent: [repeat] - https://rxjs.dev/api/operators/repeat
 //
 // WARNING: This creates an INFINITE sequence for non-empty inputs. It must be used with

v2/iterator/iter/first.go

@@ -23,6 +23,16 @@ import "github.com/IBM/fp-go/v2/option"
 // contains at least one element, it returns Some(element). If the iterator is empty,
 // it returns None. The function consumes only the first element of the iterator.
 //
+// Marble Diagram:
+//
+//	Input:  --1--2--3--4--5-->
+//	First
+//	Output: --Some(1)|
+//
+//	Input:  --|
+//	First
+//	Output: --None|
+//
 // RxJS Equivalent: [first] - https://rxjs.dev/api/operators/first
 //
 // Type Parameters:

v2/iterator/iter/iter.go

@@ -82,6 +82,12 @@ func Of2[K, A any](k K, a A) Seq2[K, A] {
 // MonadMap transforms each element in a sequence using the provided function.
 // This is the monadic version that takes the sequence as the first parameter.
 //
+// Marble Diagram:
+//
+//	Input:  --1--2--3-->
+//	Map(x => x * 2)
+//	Output: --2--4--6-->
+//
 // RxJS Equivalent: [map] - https://rxjs.dev/api/operators/map
 //
 // Example:
@@ -186,6 +192,12 @@ func MapWithKey[K, A, B any](f func(K, A) B) Operator2[K, A, B] {
 
 // MonadFilter returns a sequence containing only elements that satisfy the predicate.
 //
+// Marble Diagram:
+//
+//	Input:  --1--2--3--4--5-->
+//	Filter(x => x % 2 == 0)
+//	Output: -----2-----4----->
+//
 // RxJS Equivalent: [filter] - https://rxjs.dev/api/operators/filter
 //
 // Example:
@@ -293,6 +305,12 @@ func FilterWithKey[K, A any](pred func(K, A) bool) Operator2[K, A, A] {
 // MonadFilterMap applies a function that returns an Option to each element,
 // keeping only the Some values and unwrapping them.
 //
+// Marble Diagram:
+//
+//	Input:  --1--2--3--4--5-->
+//	FilterMap(x => x % 2 == 0 ? Some(x * 10) : None)
+//	Output: -----20----40---->
+//
 // Example:
 //
 //	seq := From(1, 2, 3, 4, 5)
@@ -430,6 +448,12 @@ func FilterMapWithKey[K, A, B any](f func(K, A) Option[B]) Operator2[K, A, B] {
 // MonadChain applies a function that returns a sequence to each element and flattens the results.
 // This is the monadic bind operation (flatMap).
 //
+// Marble Diagram:
+//
+//	Input:  --1-----2-----3---->
+//	Chain(x => [x, x*10])
+//	Output: --1-10--2-20--3-30->
+//
 // RxJS Equivalent: [mergeMap/flatMap] - https://rxjs.dev/api/operators/mergeMap
 //
 // Example:
@@ -473,6 +497,12 @@ func FlatMap[A, B any](f func(A) Seq[B]) Operator[A, B] {
 
 // Flatten flattens a sequence of sequences into a single sequence.
 //
+// Marble Diagram:
+//
+//	Input:  --[1,2]--[3,4]--[5]-->
+//	Flatten
+//	Output: --1-2----3-4----5---->
+//
 // RxJS Equivalent: [mergeAll] - https://rxjs.dev/api/operators/mergeAll
 //
 // Example:
@@ -489,6 +519,14 @@ func Flatten[A any](mma Seq[Seq[A]]) Seq[A] {
 // MonadAp applies a sequence of functions to a sequence of values.
 // This is the applicative apply operation.
 //
+// Marble Diagram:
+//
+//	Functions: --(*2)---(+10)-->
+//	Values:    --5------3------>
+//	Ap
+//	Output:    --10-6---15-13-->
+//	           (each function applied to each value)
+//
 // Example:
 //
 //	fns := From(N.Mul(2), N.Add(10))
@@ -577,6 +615,13 @@ func Replicate[A any](n int, a A) Seq[A] {
 // MonadReduce reduces a sequence to a single value by applying a function to each element
 // and an accumulator, starting with an initial value.
 //
+// Marble Diagram:
+//
+//	Input:  --1--2--3--4--5--|
+//	Reduce((acc, x) => acc + x, 0)
+//	Output: ------------------15|
+//	        (emits final result only)
+//
 // RxJS Equivalent: [reduce] - https://rxjs.dev/api/operators/reduce
 //
 // Example:
@@ -811,6 +856,13 @@ func FoldMapWithKey[K, A, B any](m M.Monoid[B]) func(func(K, A) B) func(Seq2[K,
 // MonadFlap applies a fixed value to a sequence of functions.
 // This is the dual of MonadAp.
 //
+// Marble Diagram:
+//
+//	Functions: --(*2)---(+10)-->
+//	Value:     5 (fixed)
+//	Flap
+//	Output:    --10-----15----->
+//
 // Example:
 //
 //	fns := From(N.Mul(2), N.Add(10))
@@ -832,6 +884,12 @@ func Flap[B, A any](a A) Operator[func(A) B, B] {
 
 // Prepend returns a function that adds an element to the beginning of a sequence.
 //
+// Marble Diagram:
+//
+//	Input:  -----2--3--4-->
+//	Prepend(1)
+//	Output: --1--2--3--4-->
+//
 // RxJS Equivalent: [startWith] - https://rxjs.dev/api/operators/startWith
 //
 // Example:
@@ -847,6 +905,12 @@ func Prepend[A any](head A) Operator[A, A] {
 
 // Append returns a function that adds an element to the end of a sequence.
 //
+// Marble Diagram:
+//
+//	Input:  --1--2--3-----|
+//	Append(4)
+//	Output: --1--2--3--4--|
+//
 // RxJS Equivalent: [endWith] - https://rxjs.dev/api/operators/endWith
 //
 // Example:
@@ -863,6 +927,14 @@ func Append[A any](tail A) Operator[A, A] {
 // MonadZip combines two sequences into a sequence of pairs.
 // The resulting sequence stops when either input sequence is exhausted.
 //
+// Marble Diagram:
+//
+//	SeqA:   --1--2--3---->
+//	SeqB:   --a--b------->
+//	Zip
+//	Output: --(1,a)-(2,b)|
+//	        (stops when shorter sequence ends)
+//
 // RxJS Equivalent: [zip] - https://rxjs.dev/api/operators/zip
 //
 // Example:
@@ -1079,3 +1151,61 @@ func FromSeqPair[A, B any](as Seq[Pair[A, B]]) Seq2[A, B] {
 		}
 	}
 }
+
+// Skip returns an operator that skips the first n elements of a sequence.
+//
+// This function creates a transformation that discards the first n elements from
+// the source sequence and yields all remaining elements. If n is less than or equal
+// to 0, all elements are yielded. If n is greater than or equal to the sequence length,
+// an empty sequence is returned.
+//
+// The operation is lazy and only consumes elements from the source sequence as needed.
+// The first n elements are consumed and discarded, then subsequent elements are yielded.
+//
+// Marble Diagram:
+//
+//	Input:  --1--2--3--4--5--6--7--8-->
+//	Skip(3)
+//	Output: -----------4--5--6--7--8-->
+//
+// RxJS Equivalent: [skip] - https://rxjs.dev/api/operators/skip
+//
+// Type Parameters:
+//   - U: The type of elements in the sequence
+//
+// Parameters:
+//   - count: The number of elements to skip from the beginning of the sequence
+//
+// Returns:
+//   - An Operator that transforms a Seq[U] by skipping the first count elements
+//
+// Example - Skip first 3 elements:
+//
+//	seq := From(1, 2, 3, 4, 5)
+//	result := Skip[int](3)(seq)
+//	// yields: 4, 5
+//
+// Example - Skip more than available:
+//
+//	seq := From(1, 2)
+//	result := Skip[int](5)(seq)
+//	// yields: nothing (empty sequence)
+//
+// Example - Skip zero or negative:
+//
+//	seq := From(1, 2, 3)
+//	result := Skip[int](0)(seq)
+//	// yields: 1, 2, 3 (all elements)
+//
+// Example - Chaining with other operations:
+//
+//	seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+//	result := F.Pipe2(
+//	    seq,
+//	    Skip[int](3),
+//	    MonadFilter(seq, func(x int) bool { return x%2 == 0 }),
+//	)
+//	// yields: 4, 6, 8, 10 (skip first 3, then filter evens)
+func Skip[U any](count int) Operator[U, U] {
+	return FilterWithIndex(func(idx int, _ U) bool { return idx >= count })
+}

v2/iterator/iter/iter_test.go

@@ -612,3 +612,440 @@ func TestMapToArrayIdentity(t *testing.T) {
 	result := mapper(seq)
 	assert.Equal(t, []string{"a", "b", "c"}, result)
 }
+
+// TestSkip tests basic Skip functionality
+func TestSkip(t *testing.T) {
+	t.Run("skips first n elements from sequence", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		result := toSlice(Skip[int](3)(seq))
+		assert.Equal(t, []int{4, 5}, result)
+	})
+
+	t.Run("skips first element", func(t *testing.T) {
+		seq := From(10, 20, 30)
+		result := toSlice(Skip[int](1)(seq))
+		assert.Equal(t, []int{20, 30}, result)
+	})
+
+	t.Run("skips all elements when n equals length", func(t *testing.T) {
+		seq := From(1, 2, 3)
+		result := toSlice(Skip[int](3)(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("skips all elements when n exceeds length", func(t *testing.T) {
+		seq := From(1, 2, 3)
+		result := toSlice(Skip[int](10)(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("skips from string sequence", func(t *testing.T) {
+		seq := From("a", "b", "c", "d", "e")
+		result := toSlice(Skip[string](2)(seq))
+		assert.Equal(t, []string{"c", "d", "e"}, result)
+	})
+
+	t.Run("skips from single element sequence", func(t *testing.T) {
+		seq := From(42)
+		result := toSlice(Skip[int](1)(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("skips from large sequence", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		result := toSlice(Skip[int](7)(seq))
+		assert.Equal(t, []int{8, 9, 10}, result)
+	})
+}
+
+// TestSkipZeroOrNegative tests Skip with zero or negative values
+func TestSkipZeroOrNegative(t *testing.T) {
+	t.Run("returns all elements when n is zero", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		result := toSlice(Skip[int](0)(seq))
+		assert.Equal(t, []int{1, 2, 3, 4, 5}, result)
+	})
+
+	t.Run("returns all elements when n is negative", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		result := toSlice(Skip[int](-1)(seq))
+		assert.Equal(t, []int{1, 2, 3, 4, 5}, result)
+	})
+
+	t.Run("returns all elements when n is large negative", func(t *testing.T) {
+		seq := From("a", "b", "c")
+		result := toSlice(Skip[string](-100)(seq))
+		assert.Equal(t, []string{"a", "b", "c"}, result)
+	})
+}
+
+// TestSkipEmpty tests Skip with empty sequences
+func TestSkipEmpty(t *testing.T) {
+	t.Run("returns empty from empty integer sequence", func(t *testing.T) {
+		seq := Empty[int]()
+		result := toSlice(Skip[int](5)(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("returns empty from empty string sequence", func(t *testing.T) {
+		seq := Empty[string]()
+		result := toSlice(Skip[string](3)(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("returns empty when skipping zero from empty", func(t *testing.T) {
+		seq := Empty[int]()
+		result := toSlice(Skip[int](0)(seq))
+		assert.Empty(t, result)
+	})
+}
+
+// TestSkipWithComplexTypes tests Skip with complex data types
+func TestSkipWithComplexTypes(t *testing.T) {
+	type Person struct {
+		Name string
+		Age  int
+	}
+
+	t.Run("skips structs", func(t *testing.T) {
+		seq := From(
+			Person{"Alice", 30},
+			Person{"Bob", 25},
+			Person{"Charlie", 35},
+			Person{"David", 28},
+		)
+		result := toSlice(Skip[Person](2)(seq))
+		expected := []Person{
+			{"Charlie", 35},
+			{"David", 28},
+		}
+		assert.Equal(t, expected, result)
+	})
+
+	t.Run("skips pointers", func(t *testing.T) {
+		p1 := &Person{"Alice", 30}
+		p2 := &Person{"Bob", 25}
+		p3 := &Person{"Charlie", 35}
+		seq := From(p1, p2, p3)
+		result := toSlice(Skip[*Person](1)(seq))
+		assert.Equal(t, []*Person{p2, p3}, result)
+	})
+
+	t.Run("skips slices", func(t *testing.T) {
+		seq := From([]int{1, 2}, []int{3, 4}, []int{5, 6}, []int{7, 8})
+		result := toSlice(Skip[[]int](2)(seq))
+		expected := [][]int{{5, 6}, {7, 8}}
+		assert.Equal(t, expected, result)
+	})
+}
+
+// TestSkipWithChainedOperations tests Skip with other sequence operations
+func TestSkipWithChainedOperations(t *testing.T) {
+	t.Run("skip after map", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		mapped := MonadMap(seq, N.Mul(2))
+		result := toSlice(Skip[int](2)(mapped))
+		assert.Equal(t, []int{6, 8, 10}, result)
+	})
+
+	t.Run("skip after filter", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		filtered := MonadFilter(seq, func(x int) bool { return x%2 == 0 })
+		result := toSlice(Skip[int](2)(filtered))
+		assert.Equal(t, []int{6, 8, 10}, result)
+	})
+
+	t.Run("map after skip", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		skipped := Skip[int](2)(seq)
+		result := toSlice(MonadMap(skipped, N.Mul(10)))
+		assert.Equal(t, []int{30, 40, 50}, result)
+	})
+
+	t.Run("filter after skip", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8)
+		skipped := Skip[int](2)(seq)
+		result := toSlice(MonadFilter(skipped, func(x int) bool { return x%2 == 0 }))
+		assert.Equal(t, []int{4, 6, 8}, result)
+	})
+
+	t.Run("skip after chain", func(t *testing.T) {
+		seq := From(1, 2, 3)
+		chained := MonadChain(seq, func(x int) Seq[int] {
+			return From(x, x*10)
+		})
+		result := toSlice(Skip[int](3)(chained))
+		assert.Equal(t, []int{20, 3, 30}, result)
+	})
+
+	t.Run("multiple skips", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		skipped1 := Skip[int](2)(seq)
+		skipped2 := Skip[int](3)(skipped1)
+		result := toSlice(skipped2)
+		assert.Equal(t, []int{6, 7, 8, 9, 10}, result)
+	})
+
+	t.Run("skip and take", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		skipped := Skip[int](3)(seq)
+		taken := Take[int](3)(skipped)
+		result := toSlice(taken)
+		assert.Equal(t, []int{4, 5, 6}, result)
+	})
+
+	t.Run("take and skip", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		taken := Take[int](7)(seq)
+		skipped := Skip[int](2)(taken)
+		result := toSlice(skipped)
+		assert.Equal(t, []int{3, 4, 5, 6, 7}, result)
+	})
+}
+
+// TestSkipWithReplicate tests Skip with Replicate
+func TestSkipWithReplicate(t *testing.T) {
+	t.Run("skips from replicated sequence", func(t *testing.T) {
+		seq := Replicate(10, 42)
+		result := toSlice(Skip[int](7)(seq))
+		assert.Equal(t, []int{42, 42, 42}, result)
+	})
+
+	t.Run("skips all from short replicate", func(t *testing.T) {
+		seq := Replicate(2, "hello")
+		result := toSlice(Skip[string](5)(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("skips zero from replicate", func(t *testing.T) {
+		seq := Replicate(3, 100)
+		result := toSlice(Skip[int](0)(seq))
+		assert.Equal(t, []int{100, 100, 100}, result)
+	})
+}
+
+// TestSkipWithMakeBy tests Skip with MakeBy
+func TestSkipWithMakeBy(t *testing.T) {
+	t.Run("skips from generated sequence", func(t *testing.T) {
+		seq := MakeBy(10, func(i int) int { return i * i })
+		result := toSlice(Skip[int](5)(seq))
+		assert.Equal(t, []int{25, 36, 49, 64, 81}, result)
+	})
+
+	t.Run("skips more than generated", func(t *testing.T) {
+		seq := MakeBy(3, func(i int) int { return i + 1 })
+		result := toSlice(Skip[int](10)(seq))
+		assert.Empty(t, result)
+	})
+}
+
+// TestSkipWithPrependAppend tests Skip with Prepend and Append
+func TestSkipWithPrependAppend(t *testing.T) {
+	t.Run("skip from prepended sequence", func(t *testing.T) {
+		seq := From(2, 3, 4, 5)
+		prepended := Prepend(1)(seq)
+		result := toSlice(Skip[int](2)(prepended))
+		assert.Equal(t, []int{3, 4, 5}, result)
+	})
+
+	t.Run("skip from appended sequence", func(t *testing.T) {
+		seq := From(1, 2, 3)
+		appended := Append(4)(seq)
+		result := toSlice(Skip[int](2)(appended))
+		assert.Equal(t, []int{3, 4}, result)
+	})
+
+	t.Run("skip includes appended element", func(t *testing.T) {
+		seq := From(1, 2, 3)
+		appended := Append(4)(seq)
+		result := toSlice(Skip[int](3)(appended))
+		assert.Equal(t, []int{4}, result)
+	})
+}
+
+// TestSkipWithFlatten tests Skip with Flatten
+func TestSkipWithFlatten(t *testing.T) {
+	t.Run("skips from flattened sequence", func(t *testing.T) {
+		nested := From(From(1, 2), From(3, 4), From(5, 6))
+		flattened := Flatten(nested)
+		result := toSlice(Skip[int](3)(flattened))
+		assert.Equal(t, []int{4, 5, 6}, result)
+	})
+
+	t.Run("skips from flattened with empty inner sequences", func(t *testing.T) {
+		nested := From(From(1, 2), Empty[int](), From(3, 4))
+		flattened := Flatten(nested)
+		result := toSlice(Skip[int](2)(flattened))
+		assert.Equal(t, []int{3, 4}, result)
+	})
+}
+
+// TestSkipDoesNotConsumeSkippedElements tests that Skip is efficient
+func TestSkipDoesNotConsumeSkippedElements(t *testing.T) {
+	t.Run("processes all elements including skipped", func(t *testing.T) {
+		callCount := 0
+		seq := MonadMap(From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10), func(x int) int {
+			callCount++
+			return x * 2
+		})
+
+		skipped := Skip[int](7)(seq)
+
+		result := []int{}
+		for v := range skipped {
+			result = append(result, v)
+		}
+
+		assert.Equal(t, []int{16, 18, 20}, result)
+		// Skip still needs to iterate through skipped elements to count them
+		assert.Equal(t, 10, callCount, "should process all elements")
+	})
+}
+
+// TestSkipEdgeCases tests edge cases
+func TestSkipEdgeCases(t *testing.T) {
+	t.Run("skip 0 from single element", func(t *testing.T) {
+		seq := From(42)
+		result := toSlice(Skip[int](0)(seq))
+		assert.Equal(t, []int{42}, result)
+	})
+
+	t.Run("skip 1 from single element", func(t *testing.T) {
+		seq := From(42)
+		result := toSlice(Skip[int](1)(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("skip large number from small sequence", func(t *testing.T) {
+		seq := From(1, 2)
+		result := toSlice(Skip[int](1000000)(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("skip with very large n", func(t *testing.T) {
+		seq := From(1, 2, 3)
+		result := toSlice(Skip[int](int(^uint(0) >> 1))(seq)) // max int
+		assert.Empty(t, result)
+	})
+
+	t.Run("skip all but one", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		result := toSlice(Skip[int](4)(seq))
+		assert.Equal(t, []int{5}, result)
+	})
+}
+
+// Benchmark tests for Skip
+func BenchmarkSkip(b *testing.B) {
+	seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+	b.ResetTimer()
+	for range b.N {
+		skipped := Skip[int](5)(seq)
+		for range skipped {
+		}
+	}
+}
+
+func BenchmarkSkipLargeSequence(b *testing.B) {
+	data := make([]int, 1000)
+	for i := range data {
+		data[i] = i
+	}
+	seq := From(data...)
+	b.ResetTimer()
+	for range b.N {
+		skipped := Skip[int](900)(seq)
+		for range skipped {
+		}
+	}
+}
+
+func BenchmarkSkipWithMap(b *testing.B) {
+	seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+	b.ResetTimer()
+	for range b.N {
+		mapped := MonadMap(seq, N.Mul(2))
+		skipped := Skip[int](5)(mapped)
+		for range skipped {
+		}
+	}
+}
+
+func BenchmarkSkipWithFilter(b *testing.B) {
+	seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+	b.ResetTimer()
+	for range b.N {
+		filtered := MonadFilter(seq, func(x int) bool { return x%2 == 0 })
+		skipped := Skip[int](2)(filtered)
+		for range skipped {
+		}
+	}
+}
+
+// Example tests for documentation
+func ExampleSkip() {
+	seq := From(1, 2, 3, 4, 5)
+	skipped := Skip[int](3)(seq)
+
+	for v := range skipped {
+		fmt.Printf("%d ", v)
+	}
+	// Output: 4 5
+}
+
+func ExampleSkip_moreThanAvailable() {
+	seq := From(1, 2, 3)
+	skipped := Skip[int](10)(seq)
+
+	count := 0
+	for range skipped {
+		count++
+	}
+	fmt.Printf("Count: %d\n", count)
+	// Output: Count: 0
+}
+
+func ExampleSkip_zero() {
+	seq := From(1, 2, 3, 4, 5)
+	skipped := Skip[int](0)(seq)
+
+	for v := range skipped {
+		fmt.Printf("%d ", v)
+	}
+	// Output: 1 2 3 4 5
+}
+
+func ExampleSkip_withFilter() {
+	seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+	evens := MonadFilter(seq, func(x int) bool { return x%2 == 0 })
+	skipped := Skip[int](2)(evens)
+
+	for v := range skipped {
+		fmt.Printf("%d ", v)
+	}
+	// Output: 6 8 10
+}
+
+func ExampleSkip_withMap() {
+	seq := From(1, 2, 3, 4, 5)
+	doubled := MonadMap(seq, N.Mul(2))
+	skipped := Skip[int](2)(doubled)
+
+	for v := range skipped {
+		fmt.Printf("%d ", v)
+	}
+	// Output: 6 8 10
+}
+
+func ExampleSkip_chained() {
+	seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+	result := F.Pipe3(
+		seq,
+		Skip[int](3),
+		Filter(func(x int) bool { return x%2 == 0 }),
+		toSlice[int],
+	)
+
+	fmt.Println(result)
+	// Output: [4 6 8 10]
+}

v2/iterator/iter/last.go

@@ -10,6 +10,16 @@ import (
 // sequence. If the iterator contains at least one element, it returns Some(element).
 // If the iterator is empty, it returns None.
 //
+// Marble Diagram:
+//
+//	Input:  --1--2--3--4--5--|
+//	Last
+//	Output: -----------------Some(5)|
+//
+//	Input:  --|
+//	Last
+//	Output: --None|
+//
 // RxJS Equivalent: [last] - https://rxjs.dev/api/operators/last
 //
 // Type Parameters:

v2/iterator/iter/option.go

@@ -28,6 +28,13 @@ import (
 //
 // This is the monadic form that takes the sequence as the first parameter.
 //
+// Marble Diagram:
+//
+//	Input:  --1--2--3--4--5-->
+//	ChainOptionK(x => x % 2 == 0 ? Some(x * 10) : None)
+//	Output: -----20----40---->
+//	        (filters and transforms)
+//
 // RxJS Equivalent: [concatMap] combined with [filter] - https://rxjs.dev/api/operators/concatMap
 //
 // Type parameters:
@@ -72,6 +79,13 @@ func MonadChainOptionK[A, B any](as Seq[A], f option.Kleisli[A, B]) Seq[B] {
 // This is the curried version of [MonadChainOptionK], useful for function composition
 // and creating reusable transformations.
 //
+// Marble Diagram:
+//
+//	Input:  --1--2--3--4--5-->
+//	ChainOptionK(x => x > 2 ? Some(x) : None)
+//	Output: --------3--4--5-->
+//	        (filters out values <= 2)
+//
 // RxJS Equivalent: [concatMap] combined with [filter] - https://rxjs.dev/api/operators/concatMap
 //
 // Type parameters:

v2/iterator/iter/scan.go

@@ -24,6 +24,13 @@ package iter
 //
 // The operation is lazy - intermediate values are computed only as they are consumed.
 //
+// Marble Diagram:
+//
+//	Input:  --1--2--3--4--5-->
+//	Scan((acc, x) => acc + x, 0)
+//	Output: --1--3--6--10-15->
+//	        (running sum)
+//
 // RxJS Equivalent: [scan] - https://rxjs.dev/api/operators/scan
 //
 // Scan is useful for:

v2/iterator/iter/take.go

@@ -27,6 +27,12 @@ import F "github.com/IBM/fp-go/v2/function"
 // Once n elements have been yielded, iteration stops immediately without consuming
 // the remaining elements from the source.
 //
+// Marble Diagram:
+//
+//	Input:  --1--2--3--4--5--6--7--8-->
+//	Take(3)
+//	Output: --1--2--3|
+//
 // RxJS Equivalent: [take] - https://rxjs.dev/api/operators/take
 //
 // Type Parameters:
@@ -78,3 +84,158 @@ func Take[U any](n int) Operator[U, U] {
 		}
 	}
 }
+
+// TakeWhile returns an operator that emits elements from a sequence while a predicate is satisfied.
+//
+// This function creates a transformation that yields elements from the source sequence
+// as long as each element satisfies the provided predicate. Once an element fails the
+// predicate test, the sequence terminates immediately, and no further elements are
+// emitted, even if subsequent elements would satisfy the predicate.
+//
+// The operation is lazy and only consumes elements from the source sequence as needed.
+// Once the predicate returns false, iteration stops immediately without consuming
+// the remaining elements from the source.
+//
+// Marble Diagram:
+//
+//	Input:       --1--2--3--4--5--2--1-->
+//	TakeWhile(x < 4)
+//	Output:      --1--2--3|
+//	                      (stops at 4)
+//
+// RxJS Equivalent: [takeWhile] - https://rxjs.dev/api/operators/takeWhile
+//
+// Type Parameters:
+//   - U: The type of elements in the sequence
+//
+// Parameters:
+//   - p: A predicate function that tests each element. Returns true to continue, false to stop
+//
+// Returns:
+//   - An Operator that transforms a Seq[U] by taking elements while the predicate is satisfied
+//
+// Example - Take while less than threshold:
+//
+//	seq := From(1, 2, 3, 4, 5, 2, 1)
+//	result := TakeWhile(func(x int) bool { return x < 4 })(seq)
+//	// yields: 1, 2, 3 (stops at 4, doesn't continue to 2, 1)
+//
+// Example - Take while condition is met:
+//
+//	seq := From("a", "b", "c", "1", "d", "e")
+//	isLetter := func(s string) bool { return s >= "a" && s <= "z" }
+//	result := TakeWhile(isLetter)(seq)
+//	// yields: "a", "b", "c" (stops at "1")
+//
+// Example - Take all when predicate always true:
+//
+//	seq := From(2, 4, 6, 8)
+//	result := TakeWhile(func(x int) bool { return x%2 == 0 })(seq)
+//	// yields: 2, 4, 6, 8 (all elements satisfy predicate)
+//
+// Example - Take none when first element fails:
+//
+//	seq := From(5, 1, 2, 3)
+//	result := TakeWhile(func(x int) bool { return x < 5 })(seq)
+//	// yields: nothing (first element fails predicate)
+//
+// Example - Chaining with other operations:
+//
+//	seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+//	result := F.Pipe2(
+//	    seq,
+//	    MonadMap(seq, func(x int) int { return x * 2 }),
+//	    TakeWhile(func(x int) bool { return x < 10 }),
+//	)
+//	// yields: 2, 4, 6, 8 (stops when doubled value reaches 10)
+func TakeWhile[U any](p Predicate[U]) Operator[U, U] {
+	return func(s Seq[U]) Seq[U] {
+		return func(yield func(U) bool) {
+			for u := range s {
+				if !p(u) || !yield(u) {
+					return
+				}
+			}
+		}
+	}
+}
+
+// SkipWhile returns an operator that skips elements from a sequence while a predicate is satisfied.
+//
+// This function creates a transformation that discards elements from the source sequence
+// as long as each element satisfies the provided predicate. Once an element fails the
+// predicate test, that element and all subsequent elements are yielded, regardless of
+// whether they satisfy the predicate.
+//
+// The operation is lazy and only consumes elements from the source sequence as needed.
+// Once the predicate returns false, all remaining elements are yielded without further
+// predicate evaluation.
+//
+// Marble Diagram:
+//
+//	Input:        --1--2--3--4--5--2--1-->
+//	SkipWhile(x < 4)
+//	Output:       -----------4--5--2--1-->
+//	                         (starts at 4, continues with all)
+//
+// RxJS Equivalent: [skipWhile] - https://rxjs.dev/api/operators/skipWhile
+//
+// Type Parameters:
+//   - U: The type of elements in the sequence
+//
+// Parameters:
+//   - p: A predicate function that tests each element. Returns true to skip, false to start yielding
+//
+// Returns:
+//   - An Operator that transforms a Seq[U] by skipping elements while the predicate is satisfied
+//
+// Example - Skip while less than threshold:
+//
+//	seq := From(1, 2, 3, 4, 5, 2, 1)
+//	result := SkipWhile(func(x int) bool { return x < 4 })(seq)
+//	// yields: 4, 5, 2, 1 (starts at 4, continues with all remaining)
+//
+// Example - Skip while condition is met:
+//
+//	seq := From("a", "b", "c", "1", "d", "e")
+//	isLetter := func(s string) bool { return s >= "a" && s <= "z" }
+//	result := SkipWhile(isLetter)(seq)
+//	// yields: "1", "d", "e" (starts at "1", continues with all remaining)
+//
+// Example - Skip none when first element fails:
+//
+//	seq := From(5, 1, 2, 3)
+//	result := SkipWhile(func(x int) bool { return x < 5 })(seq)
+//	// yields: 5, 1, 2, 3 (first element fails predicate, all yielded)
+//
+// Example - Skip all when predicate always true:
+//
+//	seq := From(2, 4, 6, 8)
+//	result := SkipWhile(func(x int) bool { return x%2 == 0 })(seq)
+//	// yields: nothing (all elements satisfy predicate)
+//
+// Example - Chaining with other operations:
+//
+//	seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+//	result := F.Pipe2(
+//	    seq,
+//	    SkipWhile(func(x int) bool { return x < 5 }),
+//	    MonadMap(seq, func(x int) int { return x * 2 }),
+//	)
+//	// yields: 10, 12, 14, 16, 18, 20 (skip until 5, then double remaining)
+func SkipWhile[U any](p Predicate[U]) Operator[U, U] {
+	return func(s Seq[U]) Seq[U] {
+		return func(yield func(U) bool) {
+			skipping := true
+			for u := range s {
+				if skipping && p(u) {
+					continue
+				}
+				skipping = false
+				if !yield(u) {
+					return
+				}
+			}
+		}
+	}
+}

v2/iterator/iter/take_test.go

@@ -461,3 +461,831 @@ func ExampleTake_chained() {
 	}
 	// Output: 4 5 6 7 8
 }
+
+// TestSkipWhile tests basic SkipWhile functionality
+func TestSkipWhile(t *testing.T) {
+	t.Run("skips while predicate is true", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 2, 1)
+		result := toSlice(SkipWhile(func(x int) bool { return x < 4 })(seq))
+		assert.Equal(t, []int{4, 5, 2, 1}, result)
+	})
+
+	t.Run("skips none when first element fails", func(t *testing.T) {
+		seq := From(5, 1, 2, 3)
+		result := toSlice(SkipWhile(func(x int) bool { return x < 5 })(seq))
+		assert.Equal(t, []int{5, 1, 2, 3}, result)
+	})
+
+	t.Run("skips all when predicate always true", func(t *testing.T) {
+		seq := From(2, 4, 6, 8)
+		result := toSlice(SkipWhile(func(x int) bool { return x%2 == 0 })(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("skips from string sequence", func(t *testing.T) {
+		seq := From("a", "b", "c", "1", "d", "e")
+		isLetter := func(s string) bool { return s >= "a" && s <= "z" }
+		result := toSlice(SkipWhile(isLetter)(seq))
+		assert.Equal(t, []string{"1", "d", "e"}, result)
+	})
+
+	t.Run("continues after predicate fails", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 1, 2, 3)
+		result := toSlice(SkipWhile(func(x int) bool { return x < 4 })(seq))
+		assert.Equal(t, []int{4, 1, 2, 3}, result)
+	})
+
+	t.Run("skips single element", func(t *testing.T) {
+		seq := From(1, 10, 2, 3)
+		result := toSlice(SkipWhile(func(x int) bool { return x < 10 })(seq))
+		assert.Equal(t, []int{10, 2, 3}, result)
+	})
+}
+
+// TestSkipWhileEmpty tests SkipWhile with empty sequences
+func TestSkipWhileEmpty(t *testing.T) {
+	t.Run("returns empty from empty sequence", func(t *testing.T) {
+		seq := Empty[int]()
+		result := toSlice(SkipWhile(func(x int) bool { return x > 0 })(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("returns empty when predicate always satisfied", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		result := toSlice(SkipWhile(func(x int) bool { return x < 10 })(seq))
+		assert.Empty(t, result)
+	})
+}
+
+// TestSkipWhileWithComplexTypes tests SkipWhile with complex data types
+func TestSkipWhileWithComplexTypes(t *testing.T) {
+	type Person struct {
+		Name string
+		Age  int
+	}
+
+	t.Run("skips structs while condition met", func(t *testing.T) {
+		seq := From(
+			Person{"Alice", 25},
+			Person{"Bob", 30},
+			Person{"Charlie", 35},
+			Person{"David", 28},
+		)
+		result := toSlice(SkipWhile(func(p Person) bool { return p.Age < 35 })(seq))
+		expected := []Person{
+			{"Charlie", 35},
+			{"David", 28},
+		}
+		assert.Equal(t, expected, result)
+	})
+
+	t.Run("skips pointers while condition met", func(t *testing.T) {
+		p1 := &Person{"Alice", 25}
+		p2 := &Person{"Bob", 30}
+		p3 := &Person{"Charlie", 35}
+		p4 := &Person{"David", 28}
+		seq := From(p1, p2, p3, p4)
+		result := toSlice(SkipWhile(func(p *Person) bool { return p.Age < 35 })(seq))
+		assert.Equal(t, []*Person{p3, p4}, result)
+	})
+
+	t.Run("skips slices while condition met", func(t *testing.T) {
+		seq := From([]int{1}, []int{1, 2}, []int{1, 2, 3}, []int{1})
+		result := toSlice(SkipWhile(func(s []int) bool { return len(s) < 3 })(seq))
+		expected := [][]int{{1, 2, 3}, {1}}
+		assert.Equal(t, expected, result)
+	})
+}
+
+// TestSkipWhileWithChainedOperations tests SkipWhile with other sequence operations
+func TestSkipWhileWithChainedOperations(t *testing.T) {
+	t.Run("skipWhile after map", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		mapped := MonadMap(seq, N.Mul(2))
+		result := toSlice(SkipWhile(func(x int) bool { return x < 8 })(mapped))
+		assert.Equal(t, []int{8, 10}, result)
+	})
+
+	t.Run("skipWhile after filter", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		filtered := MonadFilter(seq, func(x int) bool { return x%2 == 0 })
+		result := toSlice(SkipWhile(func(x int) bool { return x < 6 })(filtered))
+		assert.Equal(t, []int{6, 8, 10}, result)
+	})
+
+	t.Run("map after skipWhile", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		skipped := SkipWhile(func(x int) bool { return x < 4 })(seq)
+		result := toSlice(MonadMap(skipped, N.Mul(10)))
+		assert.Equal(t, []int{40, 50}, result)
+	})
+
+	t.Run("filter after skipWhile", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8)
+		skipped := SkipWhile(func(x int) bool { return x < 4 })(seq)
+		result := toSlice(MonadFilter(skipped, func(x int) bool { return x%2 == 0 }))
+		assert.Equal(t, []int{4, 6, 8}, result)
+	})
+
+	t.Run("skipWhile after chain", func(t *testing.T) {
+		seq := From(1, 2, 3)
+		chained := MonadChain(seq, func(x int) Seq[int] {
+			return From(x, x*10)
+		})
+		result := toSlice(SkipWhile(func(x int) bool { return x < 20 })(chained))
+		assert.Equal(t, []int{20, 3, 30}, result)
+	})
+
+	t.Run("skip after skipWhile", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		skipped1 := SkipWhile(func(x int) bool { return x < 4 })(seq)
+		skipped2 := Skip[int](2)(skipped1)
+		result := toSlice(skipped2)
+		assert.Equal(t, []int{6, 7, 8, 9, 10}, result)
+	})
+
+	t.Run("skipWhile after skip", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		skipped := Skip[int](3)(seq)
+		result := toSlice(SkipWhile(func(x int) bool { return x < 7 })(skipped))
+		assert.Equal(t, []int{7, 8, 9, 10}, result)
+	})
+
+	t.Run("takeWhile after skipWhile", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		skipped := SkipWhile(func(x int) bool { return x < 4 })(seq)
+		taken := TakeWhile(func(x int) bool { return x < 8 })(skipped)
+		result := toSlice(taken)
+		assert.Equal(t, []int{4, 5, 6, 7}, result)
+	})
+
+	t.Run("skipWhile after takeWhile", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		taken := TakeWhile(func(x int) bool { return x < 8 })(seq)
+		skipped := SkipWhile(func(x int) bool { return x < 4 })(taken)
+		result := toSlice(skipped)
+		assert.Equal(t, []int{4, 5, 6, 7}, result)
+	})
+}
+
+// TestSkipWhileWithReplicate tests SkipWhile with Replicate
+func TestSkipWhileWithReplicate(t *testing.T) {
+	t.Run("skips all from replicated sequence", func(t *testing.T) {
+		seq := Replicate(10, 5)
+		result := toSlice(SkipWhile(func(x int) bool { return x == 5 })(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("skips none when predicate fails on replicate", func(t *testing.T) {
+		seq := Replicate(5, 10)
+		result := toSlice(SkipWhile(func(x int) bool { return x < 10 })(seq))
+		assert.Equal(t, []int{10, 10, 10, 10, 10}, result)
+	})
+}
+
+// TestSkipWhileWithMakeBy tests SkipWhile with MakeBy
+func TestSkipWhileWithMakeBy(t *testing.T) {
+	t.Run("skips from generated sequence", func(t *testing.T) {
+		seq := MakeBy(10, func(i int) int { return i * i })
+		result := toSlice(SkipWhile(func(x int) bool { return x < 25 })(seq))
+		assert.Equal(t, []int{25, 36, 49, 64, 81}, result)
+	})
+
+	t.Run("skips all from generated sequence", func(t *testing.T) {
+		seq := MakeBy(5, func(i int) int { return i + 1 })
+		result := toSlice(SkipWhile(func(x int) bool { return x < 100 })(seq))
+		assert.Empty(t, result)
+	})
+}
+
+// TestSkipWhileWithPrependAppend tests SkipWhile with Prepend and Append
+func TestSkipWhileWithPrependAppend(t *testing.T) {
+	t.Run("skipWhile from prepended sequence", func(t *testing.T) {
+		seq := From(2, 3, 4, 5)
+		prepended := Prepend(1)(seq)
+		result := toSlice(SkipWhile(func(x int) bool { return x < 4 })(prepended))
+		assert.Equal(t, []int{4, 5}, result)
+	})
+
+	t.Run("skipWhile from appended sequence", func(t *testing.T) {
+		seq := From(1, 2, 3)
+		appended := Append(10)(seq)
+		result := toSlice(SkipWhile(func(x int) bool { return x < 10 })(appended))
+		assert.Equal(t, []int{10}, result)
+	})
+
+	t.Run("skipWhile includes appended element", func(t *testing.T) {
+		seq := From(1, 2, 3)
+		appended := Append(4)(seq)
+		result := toSlice(SkipWhile(func(x int) bool { return x < 3 })(appended))
+		assert.Equal(t, []int{3, 4}, result)
+	})
+}
+
+// TestSkipWhileWithFlatten tests SkipWhile with Flatten
+func TestSkipWhileWithFlatten(t *testing.T) {
+	t.Run("skips from flattened sequence", func(t *testing.T) {
+		nested := From(From(1, 2), From(3, 4), From(5, 6))
+		flattened := Flatten(nested)
+		result := toSlice(SkipWhile(func(x int) bool { return x < 4 })(flattened))
+		assert.Equal(t, []int{4, 5, 6}, result)
+	})
+
+	t.Run("skips from flattened with empty inner sequences", func(t *testing.T) {
+		nested := From(From(1, 2), Empty[int](), From(3, 4))
+		flattened := Flatten(nested)
+		result := toSlice(SkipWhile(func(x int) bool { return x < 3 })(flattened))
+		assert.Equal(t, []int{3, 4}, result)
+	})
+}
+
+// TestSkipWhileDoesNotConsumeEntireSequence tests that SkipWhile is lazy
+func TestSkipWhileDoesNotConsumeEntireSequence(t *testing.T) {
+	t.Run("only consumes needed elements", func(t *testing.T) {
+		callCount := 0
+		seq := MonadMap(From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10), func(x int) int {
+			callCount++
+			return x * 2
+		})
+
+		skipped := SkipWhile(func(x int) bool { return x < 8 })(seq)
+
+		result := []int{}
+		for v := range skipped {
+			result = append(result, v)
+		}
+
+		assert.Equal(t, []int{8, 10, 12, 14, 16, 18, 20}, result)
+		// Should process all elements since we iterate through all remaining
+		assert.Equal(t, 10, callCount, "should process all elements")
+	})
+
+	t.Run("stops early when consumer stops", func(t *testing.T) {
+		callCount := 0
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		filtered := MonadFilter(seq, func(x int) bool {
+			callCount++
+			return x%2 == 0
+		})
+
+		skipped := SkipWhile(func(x int) bool { return x < 6 })(filtered)
+
+		result := []int{}
+		count := 0
+		for v := range skipped {
+			result = append(result, v)
+			count++
+			if count == 2 {
+				break
+			}
+		}
+
+		assert.Equal(t, []int{6, 8}, result)
+		// Should stop after getting 2 elements
+		assert.LessOrEqual(t, callCount, 9, "should not consume all elements")
+	})
+}
+
+// TestSkipWhileEdgeCases tests edge cases
+func TestSkipWhileEdgeCases(t *testing.T) {
+	t.Run("skipWhile with always false predicate", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		result := toSlice(SkipWhile(func(x int) bool { return false })(seq))
+		assert.Equal(t, []int{1, 2, 3, 4, 5}, result)
+	})
+
+	t.Run("skipWhile with always true predicate", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		result := toSlice(SkipWhile(func(x int) bool { return true })(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("skipWhile from single element that passes", func(t *testing.T) {
+		seq := From(42)
+		result := toSlice(SkipWhile(func(x int) bool { return x > 0 })(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("skipWhile from single element that fails", func(t *testing.T) {
+		seq := From(42)
+		result := toSlice(SkipWhile(func(x int) bool { return x < 0 })(seq))
+		assert.Equal(t, []int{42}, result)
+	})
+
+	t.Run("skipWhile with complex predicate", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		result := toSlice(SkipWhile(func(x int) bool {
+			return x%2 == 1 || x < 5
+		})(seq))
+		assert.Equal(t, []int{6, 7, 8, 9, 10}, result)
+	})
+
+	t.Run("skipWhile yields elements that satisfy predicate after first failure", func(t *testing.T) {
+		seq := From(1, 2, 3, 10, 1, 2, 3)
+		result := toSlice(SkipWhile(func(x int) bool { return x < 10 })(seq))
+		assert.Equal(t, []int{10, 1, 2, 3}, result)
+	})
+}
+
+// Benchmark tests for SkipWhile
+func BenchmarkSkipWhile(b *testing.B) {
+	seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+	b.ResetTimer()
+	for range b.N {
+		skipped := SkipWhile(func(x int) bool { return x < 6 })(seq)
+		for range skipped {
+		}
+	}
+}
+
+func BenchmarkSkipWhileLargeSequence(b *testing.B) {
+	data := make([]int, 1000)
+	for i := range data {
+		data[i] = i
+	}
+	seq := From(data...)
+	b.ResetTimer()
+	for range b.N {
+		skipped := SkipWhile(func(x int) bool { return x < 100 })(seq)
+		for range skipped {
+		}
+	}
+}
+
+func BenchmarkSkipWhileWithMap(b *testing.B) {
+	seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+	b.ResetTimer()
+	for range b.N {
+		mapped := MonadMap(seq, N.Mul(2))
+		skipped := SkipWhile(func(x int) bool { return x < 12 })(mapped)
+		for range skipped {
+		}
+	}
+}
+
+func BenchmarkSkipWhileWithFilter(b *testing.B) {
+	seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+	b.ResetTimer()
+	for range b.N {
+		filtered := MonadFilter(seq, func(x int) bool { return x%2 == 0 })
+		skipped := SkipWhile(func(x int) bool { return x < 6 })(filtered)
+		for range skipped {
+		}
+	}
+}
+
+// Example tests for documentation
+func ExampleSkipWhile() {
+	seq := From(1, 2, 3, 4, 5, 2, 1)
+	skipped := SkipWhile(func(x int) bool { return x < 4 })(seq)
+
+	for v := range skipped {
+		fmt.Printf("%d ", v)
+	}
+	// Output: 4 5 2 1
+}
+
+func ExampleSkipWhile_allSatisfy() {
+	seq := From(2, 4, 6, 8)
+	skipped := SkipWhile(func(x int) bool { return x%2 == 0 })(seq)
+
+	count := 0
+	for range skipped {
+		count++
+	}
+	fmt.Printf("Count: %d\n", count)
+	// Output: Count: 0
+}
+
+func ExampleSkipWhile_firstFails() {
+	seq := From(5, 1, 2, 3)
+	skipped := SkipWhile(func(x int) bool { return x < 5 })(seq)
+
+	for v := range skipped {
+		fmt.Printf("%d ", v)
+	}
+	// Output: 5 1 2 3
+}
+
+func ExampleSkipWhile_withMap() {
+	seq := From(1, 2, 3, 4, 5)
+	doubled := MonadMap(seq, N.Mul(2))
+	skipped := SkipWhile(func(x int) bool { return x < 8 })(doubled)
+
+	for v := range skipped {
+		fmt.Printf("%d ", v)
+	}
+	// Output: 8 10
+}
+
+func ExampleSkipWhile_strings() {
+	seq := From("a", "b", "c", "1", "d", "e")
+	isLetter := func(s string) bool { return s >= "a" && s <= "z" }
+	skipped := SkipWhile(isLetter)(seq)
+
+	for v := range skipped {
+		fmt.Printf("%s ", v)
+	}
+	// Output: 1 d e
+}
+
+// TestTakeWhile tests basic TakeWhile functionality
+func TestTakeWhile(t *testing.T) {
+	t.Run("takes while predicate is true", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 2, 1)
+		result := toSlice(TakeWhile(func(x int) bool { return x < 4 })(seq))
+		assert.Equal(t, []int{1, 2, 3}, result)
+	})
+
+	t.Run("takes all when predicate always true", func(t *testing.T) {
+		seq := From(2, 4, 6, 8)
+		result := toSlice(TakeWhile(func(x int) bool { return x%2 == 0 })(seq))
+		assert.Equal(t, []int{2, 4, 6, 8}, result)
+	})
+
+	t.Run("takes none when first element fails", func(t *testing.T) {
+		seq := From(5, 1, 2, 3)
+		result := toSlice(TakeWhile(func(x int) bool { return x < 5 })(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("takes from string sequence", func(t *testing.T) {
+		seq := From("a", "b", "c", "1", "d", "e")
+		isLetter := func(s string) bool { return s >= "a" && s <= "z" }
+		result := toSlice(TakeWhile(isLetter)(seq))
+		assert.Equal(t, []string{"a", "b", "c"}, result)
+	})
+
+	t.Run("takes single element", func(t *testing.T) {
+		seq := From(1, 10, 2, 3)
+		result := toSlice(TakeWhile(func(x int) bool { return x < 10 })(seq))
+		assert.Equal(t, []int{1}, result)
+	})
+
+	t.Run("stops at first false predicate", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 1, 2, 3)
+		result := toSlice(TakeWhile(func(x int) bool { return x < 4 })(seq))
+		assert.Equal(t, []int{1, 2, 3}, result)
+	})
+}
+
+// TestTakeWhileEmpty tests TakeWhile with empty sequences
+func TestTakeWhileEmpty(t *testing.T) {
+	t.Run("returns empty from empty sequence", func(t *testing.T) {
+		seq := Empty[int]()
+		result := toSlice(TakeWhile(func(x int) bool { return x > 0 })(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("returns empty when predicate never satisfied", func(t *testing.T) {
+		seq := From(10, 20, 30)
+		result := toSlice(TakeWhile(func(x int) bool { return x < 5 })(seq))
+		assert.Empty(t, result)
+	})
+}
+
+// TestTakeWhileWithComplexTypes tests TakeWhile with complex data types
+func TestTakeWhileWithComplexTypes(t *testing.T) {
+	type Person struct {
+		Name string
+		Age  int
+	}
+
+	t.Run("takes structs while condition met", func(t *testing.T) {
+		seq := From(
+			Person{"Alice", 25},
+			Person{"Bob", 30},
+			Person{"Charlie", 35},
+			Person{"David", 28},
+		)
+		result := toSlice(TakeWhile(func(p Person) bool { return p.Age < 35 })(seq))
+		expected := []Person{
+			{"Alice", 25},
+			{"Bob", 30},
+		}
+		assert.Equal(t, expected, result)
+	})
+
+	t.Run("takes pointers while condition met", func(t *testing.T) {
+		p1 := &Person{"Alice", 25}
+		p2 := &Person{"Bob", 30}
+		p3 := &Person{"Charlie", 35}
+		seq := From(p1, p2, p3)
+		result := toSlice(TakeWhile(func(p *Person) bool { return p.Age < 35 })(seq))
+		assert.Equal(t, []*Person{p1, p2}, result)
+	})
+
+	t.Run("takes slices while condition met", func(t *testing.T) {
+		seq := From([]int{1}, []int{1, 2}, []int{1, 2, 3}, []int{1})
+		result := toSlice(TakeWhile(func(s []int) bool { return len(s) < 3 })(seq))
+		expected := [][]int{{1}, {1, 2}}
+		assert.Equal(t, expected, result)
+	})
+}
+
+// TestTakeWhileWithChainedOperations tests TakeWhile with other sequence operations
+func TestTakeWhileWithChainedOperations(t *testing.T) {
+	t.Run("takeWhile after map", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		mapped := MonadMap(seq, N.Mul(2))
+		result := toSlice(TakeWhile(func(x int) bool { return x < 8 })(mapped))
+		assert.Equal(t, []int{2, 4, 6}, result)
+	})
+
+	t.Run("takeWhile after filter", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		filtered := MonadFilter(seq, func(x int) bool { return x%2 == 0 })
+		result := toSlice(TakeWhile(func(x int) bool { return x < 7 })(filtered))
+		assert.Equal(t, []int{2, 4, 6}, result)
+	})
+
+	t.Run("map after takeWhile", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		taken := TakeWhile(func(x int) bool { return x < 4 })(seq)
+		result := toSlice(MonadMap(taken, N.Mul(10)))
+		assert.Equal(t, []int{10, 20, 30}, result)
+	})
+
+	t.Run("filter after takeWhile", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8)
+		taken := TakeWhile(func(x int) bool { return x < 7 })(seq)
+		result := toSlice(MonadFilter(taken, func(x int) bool { return x%2 == 0 }))
+		assert.Equal(t, []int{2, 4, 6}, result)
+	})
+
+	t.Run("takeWhile after chain", func(t *testing.T) {
+		seq := From(1, 2, 3)
+		chained := MonadChain(seq, func(x int) Seq[int] {
+			return From(x, x*10)
+		})
+		result := toSlice(TakeWhile(func(x int) bool { return x < 20 })(chained))
+		assert.Equal(t, []int{1, 10, 2}, result)
+	})
+
+	t.Run("take after takeWhile", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		taken1 := TakeWhile(func(x int) bool { return x < 8 })(seq)
+		taken2 := Take[int](3)(taken1)
+		result := toSlice(taken2)
+		assert.Equal(t, []int{1, 2, 3}, result)
+	})
+
+	t.Run("takeWhile after take", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		taken := Take[int](7)(seq)
+		result := toSlice(TakeWhile(func(x int) bool { return x < 5 })(taken))
+		assert.Equal(t, []int{1, 2, 3, 4}, result)
+	})
+}
+
+// TestTakeWhileWithReplicate tests TakeWhile with Replicate
+func TestTakeWhileWithReplicate(t *testing.T) {
+	t.Run("takes from replicated sequence", func(t *testing.T) {
+		seq := Replicate(10, 5)
+		result := toSlice(TakeWhile(func(x int) bool { return x == 5 })(seq))
+		assert.Equal(t, []int{5, 5, 5, 5, 5, 5, 5, 5, 5, 5}, result)
+	})
+
+	t.Run("takes none when predicate fails on replicate", func(t *testing.T) {
+		seq := Replicate(5, 10)
+		result := toSlice(TakeWhile(func(x int) bool { return x < 10 })(seq))
+		assert.Empty(t, result)
+	})
+}
+
+// TestTakeWhileWithMakeBy tests TakeWhile with MakeBy
+func TestTakeWhileWithMakeBy(t *testing.T) {
+	t.Run("takes from generated sequence", func(t *testing.T) {
+		seq := MakeBy(10, func(i int) int { return i * i })
+		result := toSlice(TakeWhile(func(x int) bool { return x < 25 })(seq))
+		assert.Equal(t, []int{0, 1, 4, 9, 16}, result)
+	})
+
+	t.Run("takes all from generated sequence", func(t *testing.T) {
+		seq := MakeBy(5, func(i int) int { return i + 1 })
+		result := toSlice(TakeWhile(func(x int) bool { return x < 100 })(seq))
+		assert.Equal(t, []int{1, 2, 3, 4, 5}, result)
+	})
+}
+
+// TestTakeWhileWithPrependAppend tests TakeWhile with Prepend and Append
+func TestTakeWhileWithPrependAppend(t *testing.T) {
+	t.Run("takeWhile from prepended sequence", func(t *testing.T) {
+		seq := From(2, 3, 4, 5)
+		prepended := Prepend(1)(seq)
+		result := toSlice(TakeWhile(func(x int) bool { return x < 4 })(prepended))
+		assert.Equal(t, []int{1, 2, 3}, result)
+	})
+
+	t.Run("takeWhile from appended sequence", func(t *testing.T) {
+		seq := From(1, 2, 3)
+		appended := Append(10)(seq)
+		result := toSlice(TakeWhile(func(x int) bool { return x < 10 })(appended))
+		assert.Equal(t, []int{1, 2, 3}, result)
+	})
+
+	t.Run("takeWhile includes appended element", func(t *testing.T) {
+		seq := From(1, 2, 3)
+		appended := Append(4)(seq)
+		result := toSlice(TakeWhile(func(x int) bool { return x < 5 })(appended))
+		assert.Equal(t, []int{1, 2, 3, 4}, result)
+	})
+}
+
+// TestTakeWhileWithFlatten tests TakeWhile with Flatten
+func TestTakeWhileWithFlatten(t *testing.T) {
+	t.Run("takes from flattened sequence", func(t *testing.T) {
+		nested := From(From(1, 2), From(3, 4), From(5, 6))
+		flattened := Flatten(nested)
+		result := toSlice(TakeWhile(func(x int) bool { return x < 5 })(flattened))
+		assert.Equal(t, []int{1, 2, 3, 4}, result)
+	})
+
+	t.Run("takes from flattened with empty inner sequences", func(t *testing.T) {
+		nested := From(From(1, 2), Empty[int](), From(3, 4))
+		flattened := Flatten(nested)
+		result := toSlice(TakeWhile(func(x int) bool { return x < 4 })(flattened))
+		assert.Equal(t, []int{1, 2, 3}, result)
+	})
+}
+
+// TestTakeWhileDoesNotConsumeEntireSequence tests that TakeWhile is lazy
+func TestTakeWhileDoesNotConsumeEntireSequence(t *testing.T) {
+	t.Run("only consumes needed elements", func(t *testing.T) {
+		callCount := 0
+		seq := MonadMap(From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10), func(x int) int {
+			callCount++
+			return x * 2
+		})
+
+		taken := TakeWhile(func(x int) bool { return x < 8 })(seq)
+
+		result := []int{}
+		for v := range taken {
+			result = append(result, v)
+		}
+
+		assert.Equal(t, []int{2, 4, 6}, result)
+		// Should stop after finding element that fails predicate
+		assert.LessOrEqual(t, callCount, 5, "should not consume significantly more than needed")
+		assert.GreaterOrEqual(t, callCount, 4, "should consume at least enough to find failure")
+	})
+
+	t.Run("stops early with filter", func(t *testing.T) {
+		callCount := 0
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		filtered := MonadFilter(seq, func(x int) bool {
+			callCount++
+			return x%2 == 0
+		})
+
+		taken := TakeWhile(func(x int) bool { return x < 7 })(filtered)
+
+		result := []int{}
+		for v := range taken {
+			result = append(result, v)
+		}
+
+		assert.Equal(t, []int{2, 4, 6}, result)
+		// Should stop after finding even number >= 7
+		assert.LessOrEqual(t, callCount, 9, "should not consume significantly more than needed")
+		assert.GreaterOrEqual(t, callCount, 7, "should consume at least enough to find 8")
+	})
+}
+
+// TestTakeWhileEdgeCases tests edge cases
+func TestTakeWhileEdgeCases(t *testing.T) {
+	t.Run("takeWhile with always false predicate", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		result := toSlice(TakeWhile(func(x int) bool { return false })(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("takeWhile with always true predicate", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5)
+		result := toSlice(TakeWhile(func(x int) bool { return true })(seq))
+		assert.Equal(t, []int{1, 2, 3, 4, 5}, result)
+	})
+
+	t.Run("takeWhile from single element that passes", func(t *testing.T) {
+		seq := From(42)
+		result := toSlice(TakeWhile(func(x int) bool { return x > 0 })(seq))
+		assert.Equal(t, []int{42}, result)
+	})
+
+	t.Run("takeWhile from single element that fails", func(t *testing.T) {
+		seq := From(42)
+		result := toSlice(TakeWhile(func(x int) bool { return x < 0 })(seq))
+		assert.Empty(t, result)
+	})
+
+	t.Run("takeWhile with complex predicate", func(t *testing.T) {
+		seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+		result := toSlice(TakeWhile(func(x int) bool {
+			return x%2 == 1 || x < 5
+		})(seq))
+		assert.Equal(t, []int{1, 2, 3, 4, 5}, result)
+	})
+}
+
+// Benchmark tests for TakeWhile
+func BenchmarkTakeWhile(b *testing.B) {
+	seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+	b.ResetTimer()
+	for range b.N {
+		taken := TakeWhile(func(x int) bool { return x < 6 })(seq)
+		for range taken {
+		}
+	}
+}
+
+func BenchmarkTakeWhileLargeSequence(b *testing.B) {
+	data := make([]int, 1000)
+	for i := range data {
+		data[i] = i
+	}
+	seq := From(data...)
+	b.ResetTimer()
+	for range b.N {
+		taken := TakeWhile(func(x int) bool { return x < 100 })(seq)
+		for range taken {
+		}
+	}
+}
+
+func BenchmarkTakeWhileWithMap(b *testing.B) {
+	seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+	b.ResetTimer()
+	for range b.N {
+		mapped := MonadMap(seq, N.Mul(2))
+		taken := TakeWhile(func(x int) bool { return x < 12 })(mapped)
+		for range taken {
+		}
+	}
+}
+
+func BenchmarkTakeWhileWithFilter(b *testing.B) {
+	seq := From(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+	b.ResetTimer()
+	for range b.N {
+		filtered := MonadFilter(seq, func(x int) bool { return x%2 == 0 })
+		taken := TakeWhile(func(x int) bool { return x < 7 })(filtered)
+		for range taken {
+		}
+	}
+}
+
+// Example tests for documentation
+func ExampleTakeWhile() {
+	seq := From(1, 2, 3, 4, 5, 2, 1)
+	taken := TakeWhile(func(x int) bool { return x < 4 })(seq)
+
+	for v := range taken {
+		fmt.Printf("%d ", v)
+	}
+	// Output: 1 2 3
+}
+
+func ExampleTakeWhile_allSatisfy() {
+	seq := From(2, 4, 6, 8)
+	taken := TakeWhile(func(x int) bool { return x%2 == 0 })(seq)
+
+	for v := range taken {
+		fmt.Printf("%d ", v)
+	}
+	// Output: 2 4 6 8
+}
+
+func ExampleTakeWhile_firstFails() {
+	seq := From(5, 1, 2, 3)
+	taken := TakeWhile(func(x int) bool { return x < 5 })(seq)
+
+	count := 0
+	for range taken {
+		count++
+	}
+	fmt.Printf("Count: %d\n", count)
+	// Output: Count: 0
+}
+
+func ExampleTakeWhile_withMap() {
+	seq := From(1, 2, 3, 4, 5)
+	doubled := MonadMap(seq, N.Mul(2))
+	taken := TakeWhile(func(x int) bool { return x < 8 })(doubled)
+
+	for v := range taken {
+		fmt.Printf("%d ", v)
+	}
+	// Output: 2 4 6
+}
+
+func ExampleTakeWhile_strings() {
+	seq := From("a", "b", "c", "1", "d", "e")
+	isLetter := func(s string) bool { return s >= "a" && s <= "z" }
+	taken := TakeWhile(isLetter)(seq)
+
+	for v := range taken {
+		fmt.Printf("%s ", v)
+	}
+	// Output: a b c
+}

v2/iterator/iter/uniq.go

@@ -32,6 +32,13 @@ import (
 // the number of unique keys encountered. The operation is lazy - elements are processed
 // and filtered as they are consumed.
 //
+// Marble Diagram:
+//
+//	Input:  --1--2--3--2--4--1--5-->
+//	Uniq(identity)
+//	Output: --1--2--3-----4-----5-->
+//	        (first occurrence only)
+//
 // RxJS Equivalent: [distinct] - https://rxjs.dev/api/operators/distinct
 //
 // Type Parameters:
@@ -119,6 +126,13 @@ func Uniq[A any, K comparable](f func(A) K) Operator[A, A] {
 // The operation maintains a map of seen elements internally, so memory usage grows with
 // the number of unique elements. Only the first occurrence of each unique element is kept.
 //
+// Marble Diagram:
+//
+//	Input:  --1--2--3--2--4--1--5-->
+//	StrictUniq
+//	Output: --1--2--3-----4-----5-->
+//	        (first occurrence only)
+//
 // RxJS Equivalent: [distinct] - https://rxjs.dev/api/operators/distinct
 //
 // Type Parameters: