gv2adj/cmd/internal/graph/dot/nodes_edges.go

/*
Copyright © 2025 filifa

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package dot

import (
	"errors"
	"strconv"

	"gonum.org/v1/gonum/graph"
	"gonum.org/v1/gonum/graph/encoding"
	"gonum.org/v1/gonum/graph/multi"
)

// Node is a DOT-aware graph.Node.
type Node struct {
	graph.Node
	dotID string
}

// SetDOTID sets the node's DOT ID. It enables storing the node name read from
// a DOT file.
func (n *Node) SetDOTID(id string) {
	n.dotID = id
}

// DOTID returns the node's DOT ID.
func (n *Node) DOTID() string {
	return n.dotID
}

// weightedLine is a DOT-aware multi.WeightedLine. By being a
// multi.WeightedLine, it allows for self-loops.
type weightedLine struct {
	multi.WeightedLine
	weightAttribute string
}

// SetAttribute enables storing the weight read from a DOT file. It errors if
// an attribute is read that can't be stored in a weightedLine.
func (e *weightedLine) SetAttribute(attr encoding.Attribute) error {
	var err error

	switch attr.Key {
	case e.weightAttribute:
		e.W, err = strconv.ParseFloat(attr.Value, 64)
	default:
		err = errors.New("unknown key:" + attr.Key)
	}

	return err
}