add comments and tests

algorithm.go

@@ -102,7 +102,7 @@ func FindEnd(first, last, sFirst, sLast ForwardReader) ForwardReader {
 	return FindEndBy(first, last, sFirst, sLast, _eq)
 }
 
-// FindEnd searches for the last occurrence of the sequence [sFirst, sLast) in
+// FindEndBy searches for the last occurrence of the sequence [sFirst, sLast) in
 // the range [first, last). If [sFirst, sLast) is empty or such sequence is
 // found, last is returned. Elements are compared using the given binary
 // predicate pred.
@@ -281,30 +281,36 @@ func FillN(first ForwardWriter, count int, v Any) {
 	}
 }
 
-// Transform
+// Transform applies the given function to the range [first, last) and stores
+// the result in another range, beginning at dFirst.
 func Transform(first, last ForwardReader, dFirst ForwardWriter, op UnaryOperation) ForwardWriter {
 	for ; _ne(first, last); dFirst, first = NextWriter(dFirst), NextReader(first) {
 		dFirst.Write(op(first.Read()))
 	}
 	return dFirst
 }
 
-// TransformBinary
+// TransformBinary applies the given function to the two ranges [first, last),
+// [first2, first2+last-first) and stores the result in another range, beginning
+// at dFirst.
 func TransformBinary(first1, last1, first2 ForwardReader, dFirst ForwardWriter, op BinaryOperation) ForwardWriter {
 	for ; _ne(first1, last1); dFirst, first1, first2 = NextWriter(dFirst), NextReader(first1), NextReader(first2) {
 		dFirst.Write(op(first1.Read(), first2.Read()))
 	}
 	return dFirst
 }
 
-// Generate
+// Generate assigns each element in range [first, last) a value generated by the
+// given function object g.
 func Generate(first, last ForwardWriter, g Generator) {
 	for ; _ne(first, last); first = NextWriter(first) {
 		first.Write(g())
 	}
 }
 
-// GenerateN
+// GenerateN assigns values, generated by given function object g, to the first
+// count elements in the range beginning at first, if count>0. Does nothing
+// otherwise.
 func GenerateN(first ForwardWriter, count int, g Generator) ForwardWriter {
 	for ; count > 0; count-- {
 		first.Write(g())
@@ -313,12 +319,15 @@ func GenerateN(first ForwardWriter, count int, g Generator) ForwardWriter {
 	return first
 }
 
-// Remove
+// Remove removes all elements equal to v from the range [first, last) and
+// returns a past-the-end iterator for the new end of the range.
 func Remove(first, last ForwardReadWriter, v Any) ForwardReadWriter {
 	return RemoveIf(first, last, _eq1(v))
 }
 
-// RemoveIf
+// RemoveIf removes all elements which predicate function returns true from the
+// range [first, last) and returns a past-the-end iterator for the new end of
+// the range.
 func RemoveIf(first, last ForwardReadWriter, pred UnaryPredicate) ForwardReadWriter {
 	first = FindIf(first, last, pred).(ForwardReadWriter)
 	if _ne(first, last) {
@@ -332,12 +341,16 @@ func RemoveIf(first, last ForwardReadWriter, pred UnaryPredicate) ForwardReadWri
 	return first
 }
 
-// RemoveCopy
+// RemoveCopy copies elements from the range [first, last), to another range
+// beginning at dFirst, omitting the elements equal to v. Source and destination
+// ranges cannot overlap.
 func RemoveCopy(first, last ForwardReader, dFirst ForwardWriter, v Any) ForwardWriter {
 	return RemoveCopyIf(first, last, dFirst, _eq1(v))
 }
 
-// RemoveCopyIf
+// RemoveCopyIf copies elements from the range [first, last), to another range
+// beginning at dFirst, omitting the elements which predicate function returns
+// true. Source and destination ranges cannot overlap.
 func RemoveCopyIf(first, last ForwardReader, dFirst ForwardWriter, pred UnaryPredicate) ForwardWriter {
 	for ; _ne(first, last); first = NextReader(first) {
 		if !pred(first.Read()) {

algorithm_test.go

@@ -284,6 +284,82 @@ func TestFillN(t *testing.T) {
 	}
 }
 
+func TestTransform(t *testing.T) {
+	a := randIntSlice()
+	var b []int
+	for _, x := range a {
+		b = append(b, x*2)
+	}
+	Transform(begin(a), end(a), begin(a), func(x Any) Any { return x.(int) * 2 })
+	sliceEqual(assert.New(t), a, b)
+}
+
+func TestTransformBinary(t *testing.T) {
+	a, b := randIntSlice(), randIntSlice()
+	if len(a) > len(b) {
+		a, b = b, a
+	}
+	c := make([]int, len(a))
+	TransformBinary(begin(a), end(a), begin(b), begin(c), func(x, y Any) Any { return x.(int) * y.(int) })
+	for i := range a {
+		a[i] *= b[i]
+	}
+	sliceEqual(assert.New(t), a, c)
+}
+
+func TestGenerate(t *testing.T) {
+	assert := assert.New(t)
+	var i int
+	g := func() Any { i++; return i }
+	a := randIntSlice()
+	Generate(begin(a), end(a), g)
+	for i := range a {
+		assert.Equal(i+1, a[i])
+	}
+}
+
+func TestGenerateN(t *testing.T) {
+	assert := assert.New(t)
+	var i int
+	g := func() Any { i++; return i }
+	a := randIntSlice()
+	b := append(a[:0:0], a...)
+	n := rand.Intn(len(a) + 1)
+	GenerateN(begin(a), n, g)
+	for i := range a {
+		if i < n {
+			assert.Equal(i+1, a[i])
+		} else {
+			assert.Equal(a[i], b[i])
+		}
+	}
+}
+
+func TestRemove(t *testing.T) {
+	assert := assert.New(t)
+	a := randIntSlice()
+	b := append(a[:0:0], a...)
+	c := append(a[:0:0], a...)
+	var d, e []int
+	f := func(x Any) bool { return x.(int)%2 == 0 }
+
+	count1 := Count(begin(a), end(a), 1)
+	countf := CountIf(begin(a), end(a), f)
+	SliceErase(&a, Remove(begin(a), end(a), 1))
+	SliceErase(&b, RemoveIf(begin(b), end(b), f))
+	RemoveCopy(begin(c), end(c), SliceBackInserter(&d), 1)
+	RemoveCopyIf(begin(c), end(c), SliceBackInserter(&e), f)
+
+	assert.Equal(Count(begin(a), end(a), 1), 0)
+	assert.True(NoneOf(begin(b), end(b), f))
+	assert.Equal(Count(begin(d), end(d), 1), 0)
+	assert.True(NoneOf(begin(e), end(e), f))
+	assert.Equal(len(a), len(c)-count1)
+	assert.Equal(len(b), len(c)-countf)
+	assert.Equal(len(d), len(c)-count1)
+	assert.Equal(len(e), len(c)-countf)
+}
+
 func TestMinmax(t *testing.T) {
 	assert := assert.New(t)
 	a, b := randInt(), randInt()

go.sum

@@ -5,6 +5,7 @@ github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZN
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+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.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=