Add an option to force-flatten switches in the graph #88
Description
Add an option to force-flatten switches in the graph.
When rendering flat-switch, the nodes don't always end up vertically aligned:
In languages that do not used clusters for other purposes (Python's exceptions, for example), we can use clusters to align the switch cases using
{
rank=same
case1
case2
case3
...
}Resulting in a cleaner, more readable graph:
The example is Go's fmt.pp.printArg in print.go:
func (p *pp) printArg(arg any, verb rune) {
p.arg = arg
p.value = reflect.Value{}
if arg == nil {
switch verb {
case 'T', 'v':
p.fmt.padString(nilAngleString)
default:
p.badVerb(verb)
}
return
}
// Special processing considerations.
// %T (the value's type) and %p (its address) are special; we always do them first.
switch verb {
case 'T':
p.fmt.fmtS(reflect.TypeOf(arg).String())
return
case 'p':
p.fmtPointer(reflect.ValueOf(arg), 'p')
return
}
// Some types can be done without reflection.
switch f := arg.(type) {
case bool:
p.fmtBool(f, verb)
case float32:
p.fmtFloat(float64(f), 32, verb)
case float64:
p.fmtFloat(f, 64, verb)
case complex64:
p.fmtComplex(complex128(f), 64, verb)
case complex128:
p.fmtComplex(f, 128, verb)
case int:
p.fmtInteger(uint64(f), signed, verb)
case int8:
p.fmtInteger(uint64(f), signed, verb)
case int16:
p.fmtInteger(uint64(f), signed, verb)
case int32:
p.fmtInteger(uint64(f), signed, verb)
case int64:
p.fmtInteger(uint64(f), signed, verb)
case uint:
p.fmtInteger(uint64(f), unsigned, verb)
case uint8:
p.fmtInteger(uint64(f), unsigned, verb)
case uint16:
p.fmtInteger(uint64(f), unsigned, verb)
case uint32:
p.fmtInteger(uint64(f), unsigned, verb)
case uint64:
p.fmtInteger(f, unsigned, verb)
case uintptr:
p.fmtInteger(uint64(f), unsigned, verb)
case string:
p.fmtString(f, verb)
case []byte:
p.fmtBytes(f, verb, "[]byte")
case reflect.Value:
// Handle extractable values with special methods
// since printValue does not handle them at depth 0.
if f.IsValid() && f.CanInterface() {
p.arg = f.Interface()
if p.handleMethods(verb) {
return
}
}
p.printValue(f, verb, 0)
default:
// If the type is not simple, it might have methods.
if !p.handleMethods(verb) {
// Need to use reflection, since the type had no
// interface methods that could be used for formatting.
p.printValue(reflect.ValueOf(f), verb, 0)
}
}
}