match(pattern, fn, [keys])

Returns a map-based tree that can match against simple patterns or JavaScript regular expressions. This is useful in creating virtual trees.

For example, if you are creating a /user area within a site that will handle routes like /user/[name].html, you can use match() to match that pattern and return a result.

$ ori match.ori
{
  user = Tree.match('[name].html', (match) => `<h1>${ match.name }</h1>`)
}
$ ori match.ori/user/Alice.html
<h1>Alice</h1>

The expression in parentheses defines a tree that matches patterns of the form [name].html. This tree is then used to obtain a value for the key Alice.html. Since that matches, the match() generates a result — here, using a template.

The pattern argument can take one of two forms:

1. A simple pattern like [name].html. When used to match Alice.html, the fn function will be given an object with the matches: { name: "Alice" }.
2. A standard JavaScript regular expression.

By default, the tree will have no public keys, but you can provide any map-like object as the keys argument. That tree’s values will be used as the keys for the tree returned by match().

$ ori matchDomain.ori
{
  user = Tree.match(
    '[name].html',
    (match) => `<h1>${ match.name }</h1>`,
    ["Alice.html", "Bob.html", "Carol.html"]
  )
}
$ ori matchDomain.ori/
user:
  Alice.html: <h1>Alice</h1>
  Bob.html: <h1>Bob</h1>
  Carol.html: <h1>Carol</h1>