ryml accepts setting a VAL node to a MAP node without removing val or triggering error

[biojppm]

meas:
  createParameterList:
    - Lumi
      value: 1
      relErr: 0.1
    - mu
    - alpha_syst1
    - mu
      value: 1
      low: 0
      high: 3
      const: 0

ERROR parsing yml: parse error - indentation should not increase at this point
line 4: '      value: 1' (sz=14)
         ^~~~~~~~~~~~~~  (cols 1-15)

the document was written with rapidyaml. So irrespective of whether it's valid YAML or not, I'd hope it would at least be able to parse back what it emitted :-)

Originally posted by @cburgard in #28 (comment)

[biojppm]

@cburgard can you provide a minimal example which triggers this?

[cburgard]

Hi!

Sure, here you go.

#include <ryml.hpp>
#include <c4/yml/std/map.hpp>
#include <c4/yml/std/string.hpp>

#include <iostream>

using namespace c4::yml;

int main(){
  ryml::Tree tree;
  NodeRef r = tree.rootref();
  r |= ryml::MAP;

  auto meas = r["meas"];
  meas |= ryml::MAP;

  auto plist = meas["createParameterList"];
  plist |= ryml::SEQ;

  auto lumi = plist.append_child();
  lumi << "Lumi";
  lumi |= ryml::MAP;      
  lumi["value"] << 1;
  lumi["relErr"] << 0.1;

  auto mu1 = plist.append_child();
  mu1 << "mu";
  mu1 |= ryml::MAP;      

  auto alpha = plist.append_child();
  alpha << "alpha_syst1";  
  alpha |= ryml::MAP;      
  
  auto mu = plist.append_child();
  mu << "mu";
  mu |= ryml::MAP;      
  mu["value"] << 1;
  mu["low"] << 0;
  mu["high"] << 0;
  mu["const"] << 0;

  emit(tree);

  return 1;
}

Now when moving it to an MWE, I can clearly see that the problem is related to setting the content of a node << "sometext" and afterwards declaring it to be a container with |= ryml::MAP. If the order is swapped, ryml complains (as it should).

[biojppm]

Thanks, this helps!

ryml should trigger an error, but it doesn't:

  auto mu = plist.append_child();
  mu << "mu";        // 1. this sets (or should set) mu as a VAL element
  mu |= ryml::MAP; // 2. then this will make it a MAP, all the while allowing it to remain a VAL.     
  mu["value"] << 1; // 3. this is OK, given the previous line
  //...

So this is a bug: the error should be triggered on 2.