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package parser
import (
"bytes"
"fmt"
"io"
"log"
"os/exec"
"strings"
)
func (*Parser) Adot(nodes []*Node, c string) {
if c == "" {
return
}
n := &Node{Child: nodes}
n.Dot(c, "")
}
func (n *Node) Dot(c, s string) {
dw, cmd := dotWriter(c)
n.astDot(dw, s)
if cmd == nil {
return
}
if err := cmd.Wait(); err != nil {
log.Fatal(err)
}
}
func (n *Node) Sdot(s string) string {
var buf bytes.Buffer
n.astDot(&buf, s)
return buf.String()
}
// TODO: rewrite it using Walk2
func (n *Node) astDot(out io.Writer, label string) {
fmt.Fprintf(out, "digraph ast { ")
if label != "" {
fmt.Fprintf(out, "labelloc=\"t\"; label=\"%s\";", label)
}
anc := map[*Node]*Node{}
index := map[*Node]int{}
count := 0
n.Walk(func(nod *Node) bool {
index[nod] = count
count++
for _, c := range nod.Child {
anc[c] = nod
}
name := ""
if nod.Token != nil {
name = strings.ReplaceAll(nod.Name(), `"`, `\"`)
}
fmt.Fprintf(out, "%d [label=\"%s\"]; ", index[nod], name)
if anc[nod] != nil {
fmt.Fprintf(out, "%d -> %d; ", index[anc[nod]], index[nod])
}
return true
}, nil)
fmt.Fprintf(out, "}")
if c, ok := out.(io.Closer); ok {
c.Close()
}
}
type nopCloser struct {
io.Writer
}
func (nopCloser) Close() error { return nil }
func dotWriter(dotCmd string) (io.WriteCloser, *exec.Cmd) {
if dotCmd == "" {
return nopCloser{io.Discard}, nil
}
fields := strings.Fields(dotCmd)
cmd := exec.Command(fields[0], fields[1:]...)
dotin, err := cmd.StdinPipe()
if err != nil {
log.Fatal(err)
}
if err = cmd.Start(); err != nil {
log.Fatal(err)
}
return dotin, cmd
}
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