apophany

apophany

a pattern matcher that matches sequences of things in a filtered list

What is it?

Apophany is a pattern matcher that uses an optionally filtered list, and a sequence of matching functions to match a pattern in a list of things.

Suppose you have a list like this:

[1, 2, 'three', 'four', 5, 6]

And you wanted to match the pattern of a number followed by a string, you could write two functions like this and put them in a list:

[
  item => typeof item === 'number',
  item => typeof item === 'string'
]

In this case, the pattern would match 2, 'three', and the object returned by the function would include information about these items in the array

What does ‘apophany’ mean?

An apophany is the name given to the moment when you recognize a pattern in something that isn't really there. It's the opposite of an epiphany, which is the name given to the moment when you finally recognize a pattern that has been there the whole time.

Usage

apophany(list, patterns, filter)

• list is an array of items to be matched
• patterns is an array containing functions to test each sequential token in the pattern
• filter is an optional function to be used with Array.filter() of the list

Examples