add a bug's operation iterator

1 files changed, 72 insertions, 0 deletions

diff --git a/bug/operation_iterator.go b/bug/operation_iterator.go
new file mode 100644
index 00000000..a576ddd6
--- /dev/null
+++ b/bug/operation_iterator.go
@@ -0,0 +1,72 @@
+package bug
+
+type OperationIterator struct {
+	bug       *Bug
+	packIndex int
+	opIndex   int
+}
+
+func NewOperationIterator(bug *Bug) *OperationIterator {
+	return &OperationIterator{
+		bug:       bug,
+		packIndex: 0,
+		opIndex:   -1,
+	}
+}
+
+func (it *OperationIterator) Next() bool {
+	// Special case of the staging area
+	if it.packIndex == len(it.bug.Packs)+1 {
+		pack := it.bug.Staging
+		it.opIndex++
+		return it.opIndex < len(pack.Operations)
+	}
+
+	if it.packIndex >= len(it.bug.Packs) {
+		return false
+	}
+
+	pack := it.bug.Packs[it.packIndex]
+
+	it.opIndex++
+
+	if it.opIndex < len(pack.Operations) {
+		return true
+	}
+
+	// Note: this iterator doesn't handle the empty pack case
+	it.opIndex = 0
+	it.packIndex++
+
+	// Special case of the non-empty staging area
+	if it.packIndex == len(it.bug.Packs)+1 && len(it.bug.Staging.Operations) > 0 {
+		return true
+	}
+
+	return it.packIndex < len(it.bug.Packs)
+}
+
+func (it *OperationIterator) Value() Operation {
+	// Special case of the staging area
+	if it.packIndex == len(it.bug.Packs)+1 {
+		pack := it.bug.Staging
+
+		if it.opIndex >= len(pack.Operations) {
+			panic("Iterator is not valid anymore")
+		}
+
+		return pack.Operations[it.opIndex]
+	}
+
+	if it.packIndex >= len(it.bug.Packs) {
+		panic("Iterator is not valid anymore")
+	}
+
+	pack := it.bug.Packs[it.packIndex]
+
+	if it.opIndex >= len(pack.Operations) {
+		panic("Iterator is not valid anymore")
+	}
+
+	return pack.Operations[it.opIndex]
+}