As discussed with @ingydotnet; opening here after discussion on mikefarah/yq#2406 as yq depends on this library and the bug has been confirmed to be related to this library.

Describe the bug

In the yq application, it is possible render/resolve anchors/aliases through the explode operator.

Unmarshalling fails due to parsing errors in this library.

Other used library has been confirmed not being the cause.

Reproduction

Reproduced in https://github.com/TyIsI/fafo-go-yaml/blob/main/yaml-go-yaml/main.go

More info from original issue

Input Yaml

Message.yml:

references:
    - &network.core.v1.Ping ./network/core/v1/Ping.yml
    - &network.core.v1.Pong ./network/core/v1/Pong.yml
    - &network.enums.v1.MessageType ./network/enums/v1/MessageType.yml
---
Message:
    - - type: *network.enums.v1.MessageType
        payload: *network.core.v1.Ping
      - type: *network.enums.v1.MessageType
        payload: *network.core.v1.Pong

Command

yq -P eval-all "explode(.) | select(document_index == 1)" Message.yml

Actual behavior

Error: bad file 'Message.yml': yaml: line 2: did not find expected alphabetic or numeric character

Expected behavior

Message:
  - - type: ./network/enums/v1/MessageType.yml
      payload: ./network/core/v1/Ping.yml
    - type: ./network/enums/v1/MessageType.yml
      payload: ./network/core/v1/Pong.yml

Additional context

If I remove the dots and use dashes (-) or slashes (/) instead, it also doesn't work. Single string works fine.

Easy link to the spec:
https://yaml.org/spec/1.2.2/#rule-ns-anchor-name