Convert between YAML and JSON

Goal: Turn a YAML config into JSON, or the other way around, and pick out values on the way.

Prerequisites: The built-in yaml module (and json for the reverse direction). Read the file with -I raw to get its text as a single string.

Query

YAML to JSON:

$ mq -I raw -F json 'import "yaml" | yaml::yaml_parse' config.yaml

JSON to YAML:

$ echo '{"name": "web", "replicas": 3, "tags": ["a", "b"]}' | mq -I raw 'import "json" | import "yaml" | json::json_parse | yaml::yaml_stringify'

Input (config.yaml)

name: web
replicas: 3
env:
  - name: LOG_LEVEL
    value: debug
  - name: PORT
    value: "8080"

Output

YAML to JSON:

{
  "name": "web",
  "replicas": 3,
  "env": [
    {
      "name": "LOG_LEVEL",
      "value": "debug"
    },
    {
      "name": "PORT",
      "value": "8080"
    }
  ]
}

JSON to YAML:

name: web
replicas: 3
tags:
  - a
  - b

Notes

• Pick out one part before converting, for example the env list as a table: mq -I raw 'import "yaml" | yaml::yaml_parse | get("env") | yaml::yaml_to_markdown_table' config.yaml.
• A file with several ----separated documents is parsed into an array with one entry per document.
• yaml_stringify sorts keys alphabetically, so the key order of the source is not kept.
• To read YAML frontmatter from a Markdown file, see Extract frontmatter metadata.