---

YAML

Go back (WacOS/Wiki/)

YAML (YAML Ain't Markup Language) is a human readable data serialization computer language.

The latest stable version of YAML is 1.2 (third edition) which was released on 2009 October 1st.

Basic components

Here are some basic examples of YAML

--- # Favorite movies
- Casablanca
- North by Northwest
- The Man Who Wasn't There

--- # Shopping list
[milk, pumpkin pie, eggs, juice]

--- # Indented Block
  name: John Smith
  age: 33
--- # Inline Block
{name: John Smith, age: 33}

data: |
   There once was a tall man from Ealing
   Who got on a bus to Darjeeling
       It said on the door
       "Please don't sit on the floor"
   So he carefully sat on the ceiling

data: >
   Wrapped text
   will be folded
   into a single
   paragraph

   Blank lines denote
   paragraph breaks

--- # The Smiths
- {name: John Smith, age: 33}
- name: Mary Smith
  age: 27
- [name, age]: [Rae Smith, 4]   # sequences as keys are supported
--- # People, by gender
men: [John Smith, Bill Jones]
women:
  - Mary Smith
  - Susan Williams

Advanced components

Here are some advanced components in YAML:

--- # Sequencer protocols for Laser eye surgery
- step:  &id001                  # defines anchor label &id001
    instrument:      Lasik 2000
    pulseEnergy:     5.4
    pulseDuration:   12
    repetition:      1000
    spotSize:        1mm

- step: &id002
    instrument:      Lasik 2000
    pulseEnergy:     5.0
    pulseDuration:   10
    repetition:      500
    spotSize:        2mm
- step: *id001                   # refers to the first step (with anchor &id001)
- step: *id002                   # refers to the second step
- step: *id002

---
a: 123                     # an integer
b: "123"                   # a string, disambiguated by quotes
c: 123.0                   # a float
d: !!float 123             # also a float via explicit data type prefixed by (!!)
e: !!str 123               # a string, disambiguated by explicit type
f: !!str Yes               # a string via explicit type
g: Yes                     # a boolean True (yaml1.1), string "Yes" (yaml1.2)
h: Yes we have No bananas  # a string, "Yes" and "No" disambiguated by context.

---
picture: !!binary |
  R0lGODdhDQAIAIAAAAAAANn
  Z2SwAAAAADQAIAAACF4SDGQ
  ar3xxbJ9p0qa7R0YxwzaFME
  1IAADs=

---
myObject: !myClass { name: Joe, age: 15 }

Other examples

Here is a data hierarchy in YAML.

---
receipt:     Oz-Ware Purchase Invoice
date:        2012-08-06
customer:
    first_name:   Dorothy
    family_name:  Gale

items:
    - part_no:   A4786
      descrip:   Water Bucket (Filled)
      price:     1.47
      quantity:  4

    - part_no:   E1628
      descrip:   High Heeled "Ruby" Slippers
      size:      8
      price:     133.7
      quantity:  1

bill-to:  &id001
    street: |
            123 Tornado Alley
            Suite 16
    city:   East Centerville
    state:  KS

ship-to:  *id001

specialDelivery:  >
    Follow the Yellow Brick
    Road to the Emerald City.
    Pay no attention to the
    man behind the curtain.
...

Here is indented delimiting in YAML:

---
example: >
        HTML goes into YAML without modification
message: |

        <blockquote style="font: italic 1em serif">
        <p>"Three is always greater than two,
           even for large values of two"</p>
        <p>--Author Unknown</p>
        </blockquote>
date: 2007-06-01

Source: Wikipedia

Compatibility on GitHub

GitHub doesn't show YAML usage by default in the color coded language list, but you can force the GitHub linguist to recognize the language with this script:

# YAML
*.yml linguist-detectable=true
*.yml linguist-documentation=false

Version B:

# YAML
*.yaml linguist-detectable=true
*.yaml linguist-documentation=false

Here is an expanded version:

# YAML
*.yml linguist-detectable=true
*.yml linguist-documentation=false
*.yaml linguist-detectable=true
*.yaml linguist-documentation=false

Use by Apple

I cannot determine the use of YAML by Apple.

Use by WacOS

WacOS uses YAML for certain functions, currently including:

1. Git data (such as labels, tags, and topics)

2. Sponsor info

3. Jekyll site configuration

4. Issue templates (coming soon)

This article on programming languages is a stub. You can help by expanding it!

---

Sources

Source: Wikipedia - YAML

More sources needed, Wikipedia cannot be the only source, as Wikipedia isn't really something to use as a source. More credible sources are needed.

---

Article info

Written on: 2021, Tuesday, September 14th at 3:02 pm)

Last revised on: 2021, Tuesday September 14th at 3:02 pm)

File format Markdown document (*.md *.mkd *.markdown)

Article version: 3 (2021, Sunday September 19th at 3:02 pm)

---