Canonicalise iterator receiver names

This apparently meaningless churn improves godoc readability.

graph/all_iterator.go

@@ -45,70 +45,69 @@ func NewInt64AllIterator(min, max int64) *Int64AllIterator {
 }
 
 // Start back at the beginning
-func (a *Int64AllIterator) Reset() {
-	a.at = a.min
+func (it *Int64AllIterator) Reset() {
+	it.at = it.min
 }
 
-func (a *Int64AllIterator) Close() {
-}
+func (it *Int64AllIterator) Close() {}
 
-func (a *Int64AllIterator) Clone() Iterator {
-	out := NewInt64AllIterator(a.min, a.max)
-	out.CopyTagsFrom(a)
+func (it *Int64AllIterator) Clone() Iterator {
+	out := NewInt64AllIterator(it.min, it.max)
+	out.CopyTagsFrom(it)
 	return out
 }
 
 // Prints the All iterator as just an "all".
-func (a *Int64AllIterator) DebugString(indent int) string {
-	return fmt.Sprintf("%s(%s)", strings.Repeat(" ", indent), a.Type())
+func (it *Int64AllIterator) DebugString(indent int) string {
+	return fmt.Sprintf("%s(%s)", strings.Repeat(" ", indent), it.Type())
 }
 
 // Next() on an Int64 all iterator is a simple incrementing counter.
 // Return the next integer, and mark it as the result.
-func (a *Int64AllIterator) Next() (TSVal, bool) {
-	NextLogIn(a)
-	if a.at == -1 {
-		return NextLogOut(a, nil, false)
+func (it *Int64AllIterator) Next() (TSVal, bool) {
+	NextLogIn(it)
+	if it.at == -1 {
+		return NextLogOut(it, nil, false)
 	}
-	val := a.at
-	a.at = a.at + 1
-	if a.at > a.max {
-		a.at = -1
+	val := it.at
+	it.at = it.at + 1
+	if it.at > it.max {
+		it.at = -1
 	}
-	a.Last = val
-	return NextLogOut(a, val, true)
+	it.Last = val
+	return NextLogOut(it, val, true)
 }
 
 // The number of elements in an Int64AllIterator is the size of the range.
 // The size is exact.
-func (a *Int64AllIterator) Size() (int64, bool) {
-	Size := ((a.max - a.min) + 1)
+func (it *Int64AllIterator) Size() (int64, bool) {
+	Size := ((it.max - it.min) + 1)
 	return Size, true
 }
 
 // Check() for an Int64AllIterator is merely seeing if the passed value is
 // withing the range, assuming the value is an int64.
-func (a *Int64AllIterator) Check(tsv TSVal) bool {
-	CheckLogIn(a, tsv)
+func (it *Int64AllIterator) Check(tsv TSVal) bool {
+	CheckLogIn(it, tsv)
 	v := tsv.(int64)
-	if a.min <= v && v <= a.max {
-		a.Last = v
-		return CheckLogOut(a, v, true)
+	if it.min <= v && v <= it.max {
+		it.Last = v
+		return CheckLogOut(it, v, true)
 	}
-	return CheckLogOut(a, v, false)
+	return CheckLogOut(it, v, false)
 }
 
 // The type of this iterator is an "all". This is important, as it puts it in
 // the class of "all iterators.
-func (a *Int64AllIterator) Type() string { return "all" }
+func (it *Int64AllIterator) Type() string { return "all" }
 
 // There's nothing to optimize about this little iterator.
-func (a *Int64AllIterator) Optimize() (Iterator, bool) { return a, false }
+func (it *Int64AllIterator) Optimize() (Iterator, bool) { return it, false }
 
 // Stats for an Int64AllIterator are simple. Super cheap to do any operation,
 // and as big as the range.
-func (a *Int64AllIterator) GetStats() *IteratorStats {
-	s, _ := a.Size()
+func (it *Int64AllIterator) GetStats() *IteratorStats {
+	s, _ := it.Size()
 	return &IteratorStats{
 		CheckCost: 1,
 		NextCost:  1,