Tree namespace

This is a collection of functions for working with tree structures built from maps: instances of the standard Map class, the asynchronous AsyncMap variation, or map-like objects.

Most of the Tree operations accept such a map as their first argument. If the argument is not already a Map or AsyncMap, it will be wrapped in one.

Some operations like Tree.values are inherently shallow and only work on the input as if it were a flat map. Other operations like Tree.deepValues treat their input as the root node of a map-based tree and generally walk through that tree structure.

$ ori Tree.values { a: 1, b: { c: 2 }}
- 1
- c: 2
$ ori Tree.deepValues { a: 1, b: { c: 2 }}
- 1
- 2

Here Tree.values returns the values of the map it is given, one of which is the object { c: 2 }. The Tree.deepValues function walks the tree to returns the leaf values. To reflect this, Tree.values is documented as taking a map parameter, while Tree.deepValues is documented as taking a tree parameter.

Commands by name #

Tree.addNextPrevious(map)

Add next/previous fields to the map’s values

Tree.assign(target, source)

Apply key/values from source to target

Tree.cache(tree, [cache])

Caches values from the tree

Tree.calendar(options)

Return a tree structure for years/months/days

Tree.clear(map)

Remove all values from the map

Tree.constant(value)

Return a deep tree with a single constant value

Tree.deepMap(tree, options)

Map the keys and values of a deep tree

Tree.deepMerge(…trees)

Return a deeply-merged tree

Tree.deepReverse(tree)

Reverse order of keys at all levels of the tree

Tree.deepTake(tree, n)

The first n values from the deep tree

Tree.deepText(tree)

The text values of the deep tree

Tree.deepValues(tree)

The in-order leaf values of the tree

Tree.delete(map, key)

Delete the value for the key from map

Tree.entries(map)

The map’s [key, value] pairs

Tree.filter(tree, options)

Filter a tree by a condition

Tree.first(map)

The first value in the map

Tree.forEach(map, fn)

Apply fn to each (value, key)

Tree.from(object, options)

Create a map from an object

Tree.globKeys(patterns)

A tree whose keys can include glob wildcard patterns

Tree.groupBy(map, fn)

A new map with values grouped by the function

Tree.has(map, key)

True if key exists in map

Tree.indent`…`

Tagged template literal for normalizing indentation

Tree.inners(tree)

The tree’s interior nodes

Tree.isMap(object)

True if object is a map

Tree.isMaplike(object)

True if object can be coerced to a tree

Tree.isReadOnlyMap(object)

True if object is a read-only map

Tree.isTraversable(object)

True if object is traversable

Tree.json(tree)

Render the tree in JSON format

Tree.keys(map)

The keys of the map

Tree.map(source, options)

Create a new map by transforming keys and/or values

Tree.mapExtension(source, ext, options)

Create a new map by transforming extensions

Tree.mapReduce(tree, mapFn, reduceFn)

Map the keys and/or values in a tree and reduce them

Tree.mask(source, mask)

Return the source tree with only the keys in the mask

Tree.match(pattern, fn, [keys])

Matches simple patterns or regular expressions

Tree.merge(…maps)

Return a new tree merging the given maps

Tree.paginate(map, [n])

Group the map’s values into fixed-size sets

Tree.parent(tree)

The parent of the given tree node

Tree.paths(tree)

Slash-separated paths for the tree’s values

Tree.plain(tree)

Render the tree as a plain JavaScript object

Tree.regExpKeys(tree)

A tree whose keys are regular expression strings

Tree.reverse(map)

Reverse the order of the map’s keys

Tree.root(tree)

The root node of the given tree

Tree.scope(tree)

A merged view of the tree and its ancestors

Tree.shuffle(map)

Shuffle the keys of the map

Tree.size(map)

The map’s size (number of keys)

Tree.sort(map, options)

A new map with its keys sorted

Tree.sync(tree)

Awaits all asynchronous values in the tree

Tree.take(map, n)

The first n values in the map

Tree.text`…`

Tagged template literal for rendering trees

Tree.traverse(tree, …keys)

Return the value at the path of keys

Tree.traverseOrThrow(tree, …keys)

Return the value at the path of keys or throw

Tree.traversePath(tree, path)

Traverse a slash-separated path

Tree.values(map)

The map’s values

Tree.withKeys(map, keys)

Use the given keys for the map