blob: e55ecbb6e2c6901568737b753548f1456c5c5194 [file] [log] [blame] [edit]
// Copyright ©2018 The Gonum Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build safe
package iterator
import (
"reflect"
"gonum.org/v1/gonum/graph"
)
// Nodes implements the graph.Nodes interfaces.
// The iteration order of Nodes is randomized.
type Nodes struct {
nodes reflect.Value
iter *reflect.MapIter
pos int
curr graph.Node
}
// NewNodes returns a Nodes initialized with the provided nodes, a
// map of node IDs to graph.Nodes. No check is made that the keys
// match the graph.Node IDs, and the map keys are not used.
//
// Behavior of the Nodes is unspecified if nodes is mutated after
// the call the NewNodes.
func NewNodes(nodes map[int64]graph.Node) *Nodes {
rv := reflect.ValueOf(nodes)
return &Nodes{nodes: rv, iter: rv.MapRange()}
}
// Len returns the remaining number of nodes to be iterated over.
func (n *Nodes) Len() int {
return n.nodes.Len() - n.pos
}
// Next returns whether the next call of Node will return a valid node.
func (n *Nodes) Next() bool {
if n.pos >= n.nodes.Len() {
return false
}
ok := n.iter.Next()
if ok {
n.pos++
n.curr = n.iter.Value().Interface().(graph.Node)
}
return ok
}
// Node returns the current node of the iterator. Next must have been
// called prior to a call to Node.
func (n *Nodes) Node() graph.Node {
return n.curr
}
// Reset returns the iterator to its initial state.
func (n *Nodes) Reset() {
n.curr = nil
n.pos = 0
n.iter = n.nodes.MapRange()
}
// NodeSlice returns all the remaining nodes in the iterator and advances
// the iterator. The order of nodes within the returned slice is not
// specified.
func (n *Nodes) NodeSlice() []graph.Node {
if n.Len() == 0 {
return nil
}
nodes := make([]graph.Node, 0, n.Len())
for n.iter.Next() {
nodes = append(nodes, n.iter.Value().Interface().(graph.Node))
}
n.pos = n.nodes.Len()
return nodes
}
// NodesByEdge implements the graph.Nodes interfaces.
// The iteration order of Nodes is randomized.
type NodesByEdge struct {
nodes map[int64]graph.Node
edges reflect.Value
iter *reflect.MapIter
pos int
curr graph.Node
}
// NewNodesByEdge returns a NodesByEdge initialized with the
// provided nodes, a map of node IDs to graph.Nodes, and the set
// of edges, a map of to-node IDs to graph.Edge, that can be
// traversed to reach the nodes that the NodesByEdge will iterate
// over. No check is made that the keys match the graph.Node IDs,
// and the map keys are not used.
//
// Behavior of the NodesByEdge is unspecified if nodes or edges
// is mutated after the call the NewNodes.
func NewNodesByEdge(nodes map[int64]graph.Node, edges map[int64]graph.Edge) *NodesByEdge {
rv := reflect.ValueOf(edges)
return &NodesByEdge{nodes: nodes, edges: rv, iter: rv.MapRange()}
}
// NewNodesByWeightedEdge returns a NodesByEdge initialized with the
// provided nodes, a map of node IDs to graph.Nodes, and the set
// of edges, a map of to-node IDs to graph.WeightedEdge, that can be
// traversed to reach the nodes that the NodesByEdge will iterate
// over. No check is made that the keys match the graph.Node IDs,
// and the map keys are not used.
//
// Behavior of the NodesByEdge is unspecified if nodes or edges
// is mutated after the call the NewNodes.
func NewNodesByWeightedEdge(nodes map[int64]graph.Node, edges map[int64]graph.WeightedEdge) *NodesByEdge {
rv := reflect.ValueOf(edges)
return &NodesByEdge{nodes: nodes, edges: rv, iter: rv.MapRange()}
}
// NewNodesByLines returns a NodesByEdge initialized with the
// provided nodes, a map of node IDs to graph.Nodes, and the set
// of lines, a map to-node IDs to map of graph.Line, that can be
// traversed to reach the nodes that the NodesByEdge will iterate
// over. No check is made that the keys match the graph.Node IDs,
// and the map keys are not used.
//
// Behavior of the NodesByEdge is unspecified if nodes or lines
// is mutated after the call the NewNodes.
func NewNodesByLines(nodes map[int64]graph.Node, lines map[int64]map[int64]graph.Line) *NodesByEdge {
rv := reflect.ValueOf(lines)
return &NodesByEdge{nodes: nodes, edges: rv, iter: rv.MapRange()}
}
// NewNodesByWeightedLines returns a NodesByEdge initialized with the
// provided nodes, a map of node IDs to graph.Nodes, and the set
// of lines, a map to-node IDs to map of graph.WeightedLine, that can be
// traversed to reach the nodes that the NodesByEdge will iterate
// over. No check is made that the keys match the graph.Node IDs,
// and the map keys are not used.
//
// Behavior of the NodesByEdge is unspecified if nodes or lines
// is mutated after the call the NewNodes.
func NewNodesByWeightedLines(nodes map[int64]graph.Node, lines map[int64]map[int64]graph.WeightedLine) *NodesByEdge {
rv := reflect.ValueOf(lines)
return &NodesByEdge{nodes: nodes, edges: rv, iter: rv.MapRange()}
}
// Len returns the remaining number of nodes to be iterated over.
func (n *NodesByEdge) Len() int {
return n.edges.Len() - n.pos
}
// Next returns whether the next call of Node will return a valid node.
func (n *NodesByEdge) Next() bool {
if n.pos >= n.edges.Len() {
return false
}
ok := n.iter.Next()
if ok {
n.pos++
n.curr = n.nodes[n.iter.Key().Int()]
}
return ok
}
// Node returns the current node of the iterator. Next must have been
// called prior to a call to Node.
func (n *NodesByEdge) Node() graph.Node {
return n.curr
}
// Reset returns the iterator to its initial state.
func (n *NodesByEdge) Reset() {
n.curr = nil
n.pos = 0
n.iter = n.edges.MapRange()
}
// NodeSlice returns all the remaining nodes in the iterator and advances
// the iterator. The order of nodes within the returned slice is not
// specified.
func (n *NodesByEdge) NodeSlice() []graph.Node {
if n.Len() == 0 {
return nil
}
nodes := make([]graph.Node, 0, n.Len())
for n.iter.Next() {
nodes = append(nodes, n.nodes[n.iter.Key().Int()])
}
n.pos = n.edges.Len()
return nodes
}