func minimizeMatchers(matchers []match.Matcher) []match.Matcher {
var done match.Matcher
var left, right, count int
for l := 0; l < len(matchers); l++ {
for r := len(matchers); r > l; r-- {
if glued := glueMatchers(matchers[l:r]); glued != nil {
var swap bool
if done == nil {
swap = true
} else {
cl, gl := done.Len(), glued.Len()
swap = cl > -1 && gl > -1 && gl > cl
swap = swap || count < r-l
}
if swap {
done = glued
left = l
right = r
count = r - l
}
}
}
}
if done == nil {
return matchers
}
next := append(append([]match.Matcher{}, matchers[:left]...), done)
if right < len(matchers) {
next = append(next, matchers[right:]...)
}
if len(next) == len(matchers) {
return next
}
return minimizeMatchers(next)
}
func graphviz(m match.Matcher, id string) string {
buf := &bytes.Buffer{}
switch matcher := m.(type) {
case match.BTree:
fmt.Fprintf(buf, `"%s"[label="%s"];`, id, matcher.Value.String())
for _, m := range []match.Matcher{matcher.Left, matcher.Right} {
switch n := m.(type) {
case nil:
rnd := rand.Int63()
fmt.Fprintf(buf, `"%x"[label="<nil>"];`, rnd)
fmt.Fprintf(buf, `"%s"->"%x";`, id, rnd)
default:
sub := fmt.Sprintf("%x", rand.Int63())
fmt.Fprintf(buf, `"%s"->"%s";`, id, sub)
fmt.Fprintf(buf, graphviz(n, sub))
}
}
case match.AnyOf:
fmt.Fprintf(buf, `"%s"[label="AnyOf"];`, id)
for _, m := range matcher.Matchers {
rnd := rand.Int63()
fmt.Fprintf(buf, graphviz(m, fmt.Sprintf("%x", rnd)))
fmt.Fprintf(buf, `"%s"->"%x";`, id, rnd)
}
case match.EveryOf:
fmt.Fprintf(buf, `"%s"[label="EveryOf"];`, id)
for _, m := range matcher.Matchers {
rnd := rand.Int63()
fmt.Fprintf(buf, graphviz(m, fmt.Sprintf("%x", rnd)))
fmt.Fprintf(buf, `"%s"->"%x";`, id, rnd)
}
default:
fmt.Fprintf(buf, `"%s"[label="%s"];`, id, m.String())
}
return buf.String()
}