// an interface.
func dataWord(conv *ir.ConvExpr, init *ir.Nodes) ir.Node {
	pos, n := conv.Pos(), conv.X
	fromType := n.Type()

	// If it's a pointer, it is its own representation.
	if types.IsDirectIface(fromType) {
		return n
	}

	isInteger := fromType.IsInteger()
	isBool := fromType.IsBoolean()
	if sc := fromType.SoleComponent(); sc != nil {
		isInteger = sc.IsInteger()
		isBool = sc.IsBoolean()
	}

	cases := []struct {
		desc        string
		fromType    vertexType
		toType      vertexType
		toNamespace string
		toName      string
		start       *Graph
		expect      *Graph
	}{
		{
			// single edge from a configmap to a node, will delete edge and orphaned configmap
			desc:        "edges and source orphans are deleted, destination orphans are preserved",
			fromType:    configMapVertexType,
			toType:      nodeVertexType,

// will delete each orphaned "from" vertex, but will never delete the "to" vertex
func (g *Graph) deleteEdges_locked(fromType, toType vertexType, toNamespace, toName string) {
	// get the "to" side
	toVert, exists := g.getVertex_rlocked(toType, toNamespace, toName)
	if !exists {
		return
	}

	// delete all edges between vertices of fromType and toVert
	neighborsToRemove := []*namedVertex{}
	edgesToRemove := []graph.Edge{}

type AddrPos struct {
	Addr
	Pos OperandPos
}

type OperandPos int8

const (
	Source OperandPos = iota
	Destination
)

// From3Type returns p.GetFrom3().Type, or TYPE_NONE when
// p.GetFrom3() returns nil.
func (p *Prog) From3Type() AddrType {
	from3 := p.GetFrom3()
	if from3 == nil {
		return TYPE_NONE
	}
	return from3.Type
}