@std/yaml parses yaml with anchor wrong

[taind772]

Describe the bug

import * as yaml from "jsr:@std/yaml@0.224.0"

const sample = `
test: &test
    a: 2
    b: 4
    c: 6
another:
    <<: *test
    c: 8
    d: 10
`
console.log(yaml.parse(sample))

Steps to Reproduce

❯ deno run yaml-test.ts
{
  test: { a: 2, b: 4, c: 6 },
  another: { "0": undefined, "1": undefined, "2": undefined, c: 8, d: 10 }
}

Expected behavior

❯ echo "
  test: &test
      a: 2
      b: 4
      c: 6
  another:
      <<: *test
      c: 8
      d: 10
  " | yq -o json
{
  "test": {
    "a": 2,
    "b": 4,
    "c": 6
  },
  "another": {
    "a": 2,
    "b": 4,
    "c": 8,
    "d": 10
  }
}

Environment

• OS: Linux / Arch
• deno version: 1.43.3
• std version: 0.224

[taind772]

I think the wrong part is merging.
Support or not, the output doesn't make sense to me at all. If merging is not supported, at least we should return something like

{
  test: { a: 2, b: 4, c: 6 },
  another: { "<<": { a: 2, b: 4, c: 6 }, c: 8, d: 10 }
}

I found a workaround (for my use case) by using https://www.npmjs.com/package/yaml instead:

import * as yaml from "npm:yaml"

const sample = `
test: &test
    a: 2
    b: 4
    c: 6
another:
    <<: *test
    c: 8
    d: 10
`
console.log(yaml.parse(sample, { merge: true }))

[babiabeo]

This issue has been fixed by #5185.