JSON and Algebraic Data Types
Written by Eric Normand. Published: August 17, 2012.
I recently wrote about the birth of JSON, which describes how JSON came to be and the story of its success. Crawford talks about how JSON (or a very close equivalent) was reinvented several times throughout the years.
What strikes me is that JSON turned out to be an Algrebraic Data Type (ADT). Specifically, it is a tagged union.
JSON ADT variants:
- Null
- Boolean
- Number
- String
- List
- Dictionary
With these six constructors, you can make all of JSON.
It's interesting because JSON is a point of intersection between Javascript and Haskell. Javascript is very dynamic, with a very weak sense of type. Haskell has strong typing. On close analysis, JSON is statically and strongly typed. In fact, JSON is a type.
Could its ADT nature be one of the secrets to JSON's success?