expanded example

test.rb

require "psych"
require "psych/pure"

yaml_source = <<~YAML
  # Comprehensive YAML types demonstration
  ---
  # Scalar types
  strings:
    plain: Plain string
    quoted: "Quoted string"
    single: 'Single quoted string'
    # Multi-line variants
    literal_block: |
      Line 1
      Line 2
      Line 3
    folded_block: >
      This is a very long
      paragraph that will be
      folded into a single line.
    literal_strip: |-
      Remove trailing newlines
      from this block
    literal_keep: |+
      Keep trailing newlines
      in this block
      

  numbers:
    integer: 42
    negative: -17
    float: 3.14159
    # a comment above
    scientific: 12.3e+02 # scientific notation
    zero: 0
    infinity: .inf
    neg_infinity: -.inf
    not_number: .nan
    octal: 0o14
    hex: 0xC
    binary: 0b1010
    sexagesimal: 190:20:30

  # Boolean types
  booleans:
    true_values: [true, True, TRUE, yes, Yes, YES, on, On, ON] # not ideal that it uses list syntax instead of []
    false_values: [false, False, FALSE, no, No, NO, off, Off, OFF]

  # Null values
  nulls:
    empty: ~
    null: null #BUG this comment is eaten
    Null: Null
    NULL: NULL

  # Dates and times
  dates:
    canonical: 2023-12-25
    iso8601: 2023-12-25T14:30:00.123Z
    spaced: 2023-12-25 14:30:00.123
    timestamp: 2023-12-25T14:30:00.123+02:00
    timestamp_neg: 2023-12-25T14:30:00.123-05:00

  # Collections
  sequences:
    basic: &seq_anchor
      - Item 1
      - Item 2
      - Item 3
    nested:
      - - Nested 1
        - Nested 2
      - - Nested 3 # HELLO Nested 3
        - Nested 4
    flow: [compact, inline, array]
    tagged: !!seq
      - explicit
      - sequence
      - tag

  mappings:
    basic: &map_anchor
      key1: value1
      key2: value2
    nested:
      map1:
        inner1: value
        inner2: value
    flow: {compact: map, inline: true}
    tagged: !!map
      explicit: tag
      example: value

  # Anchors and aliases
  reuse:
    sequence_alias: *seq_anchor
    mapping_alias: *map_anchor
    
  # Inheritance using merge key
  templates:
    base: &base
      setting1: value1
      setting2: value2
    derived:
      <<: *base
      setting2: override
      setting3: value3

  # Binary data
  binary: !!binary |
    R0lGODlhDAAMAIQAAP//9/X17unp5WZmZgAAAOf...

  # Explicit typing: BUG this comment drifts
  explicit_types:
    string: !!str 42
    int: !!int "42"
    float: !!float "3.14159"
    binary: !!binary |
          iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNk+A8AAQUBAScY42YAAAAASUVORK5CYII=
YAML

# Load the YAML with comments
config =
  Psych::Pure.load(
    yaml_source,
    comments: true,
    aliases: true,
    permitted_classes: [Symbol, Date, Time, Set]
  )

puts "=== Original Configuration ==="
puts Psych::Pure.dump(config)

# Demonstrate accessing different types
puts "\n=== Type Examples ==="
puts "String (folded): #{config["strings"]["folded_block"]}"
puts "Number (float): #{config["numbers"]["float"]}"
puts "Boolean: #{config["booleans"]["true_values"].first}"
puts "Date: #{config["dates"]["canonical"]}"
puts "Sequence: #{config["sequences"]["flow"].join(", ")}"
puts "Mapping: #{config["mappings"]["flow"]}"
puts "Inherited value: #{config["templates"]["derived"]["setting1"]}"
puts "Binary (partial): #{config["binary"][0, 10]}..."

# Make some modifications
config["strings"]["plain"] = "Modified string"
config["numbers"]["integer"] = 100
config["sequences"]["basic"] << "New Item"

puts "\n=== Modified Configuration ==="
puts Psych::Pure.dump(config)