123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313 |
- /**
- * @typedef {import('unist').Node} UnistNode
- * @typedef {import('unist').Parent} UnistParent
- * @typedef {import('unist-util-visit-parents').VisitorResult} VisitorResult
- */
- /**
- * @typedef {Exclude<import('unist-util-is').Test, undefined> | undefined} Test
- * Test from `unist-util-is`.
- *
- * Note: we have remove and add `undefined`, because otherwise when generating
- * automatic `.d.ts` files, TS tries to flatten paths from a local perspective,
- * which doesn’t work when publishing on npm.
- */
- // To do: use types from `unist-util-visit-parents` when it’s released.
- /**
- * @typedef {(
- * Fn extends (value: any) => value is infer Thing
- * ? Thing
- * : Fallback
- * )} Predicate
- * Get the value of a type guard `Fn`.
- * @template Fn
- * Value; typically function that is a type guard (such as `(x): x is Y`).
- * @template Fallback
- * Value to yield if `Fn` is not a type guard.
- */
- /**
- * @typedef {(
- * Check extends null | undefined // No test.
- * ? Value
- * : Value extends {type: Check} // String (type) test.
- * ? Value
- * : Value extends Check // Partial test.
- * ? Value
- * : Check extends Function // Function test.
- * ? Predicate<Check, Value> extends Value
- * ? Predicate<Check, Value>
- * : never
- * : never // Some other test?
- * )} MatchesOne
- * Check whether a node matches a primitive check in the type system.
- * @template Value
- * Value; typically unist `Node`.
- * @template Check
- * Value; typically `unist-util-is`-compatible test, but not arrays.
- */
- /**
- * @typedef {(
- * Check extends Array<any>
- * ? MatchesOne<Value, Check[keyof Check]>
- * : MatchesOne<Value, Check>
- * )} Matches
- * Check whether a node matches a check in the type system.
- * @template Value
- * Value; typically unist `Node`.
- * @template Check
- * Value; typically `unist-util-is`-compatible test.
- */
- /**
- * @typedef {0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10} Uint
- * Number; capped reasonably.
- */
- /**
- * @typedef {I extends 0 ? 1 : I extends 1 ? 2 : I extends 2 ? 3 : I extends 3 ? 4 : I extends 4 ? 5 : I extends 5 ? 6 : I extends 6 ? 7 : I extends 7 ? 8 : I extends 8 ? 9 : 10} Increment
- * Increment a number in the type system.
- * @template {Uint} [I=0]
- * Index.
- */
- /**
- * @typedef {(
- * Node extends UnistParent
- * ? Node extends {children: Array<infer Children>}
- * ? Child extends Children ? Node : never
- * : never
- * : never
- * )} InternalParent
- * Collect nodes that can be parents of `Child`.
- * @template {UnistNode} Node
- * All node types in a tree.
- * @template {UnistNode} Child
- * Node to search for.
- */
- /**
- * @typedef {InternalParent<InclusiveDescendant<Tree>, Child>} Parent
- * Collect nodes in `Tree` that can be parents of `Child`.
- * @template {UnistNode} Tree
- * All node types in a tree.
- * @template {UnistNode} Child
- * Node to search for.
- */
- /**
- * @typedef {(
- * Depth extends Max
- * ? never
- * :
- * | InternalParent<Node, Child>
- * | InternalAncestor<Node, InternalParent<Node, Child>, Max, Increment<Depth>>
- * )} InternalAncestor
- * Collect nodes in `Tree` that can be ancestors of `Child`.
- * @template {UnistNode} Node
- * All node types in a tree.
- * @template {UnistNode} Child
- * Node to search for.
- * @template {Uint} [Max=10]
- * Max; searches up to this depth.
- * @template {Uint} [Depth=0]
- * Current depth.
- */
- /**
- * @typedef {(
- * Tree extends UnistParent
- * ? Depth extends Max
- * ? Tree
- * : Tree | InclusiveDescendant<Tree['children'][number], Max, Increment<Depth>>
- * : Tree
- * )} InclusiveDescendant
- * Collect all (inclusive) descendants of `Tree`.
- *
- * > 👉 **Note**: for performance reasons, this seems to be the fastest way to
- * > recurse without actually running into an infinite loop, which the
- * > previous version did.
- * >
- * > Practically, a max of `2` is typically enough assuming a `Root` is
- * > passed, but it doesn’t improve performance.
- * > It gets higher with `List > ListItem > Table > TableRow > TableCell`.
- * > Using up to `10` doesn’t hurt or help either.
- * @template {UnistNode} Tree
- * Tree type.
- * @template {Uint} [Max=10]
- * Max; searches up to this depth.
- * @template {Uint} [Depth=0]
- * Current depth.
- */
- /**
- * @callback Visitor
- * Handle a node (matching `test`, if given).
- *
- * Visitors are free to transform `node`.
- * They can also transform `parent`.
- *
- * Replacing `node` itself, if `SKIP` is not returned, still causes its
- * descendants to be walked (which is a bug).
- *
- * When adding or removing previous siblings of `node` (or next siblings, in
- * case of reverse), the `Visitor` should return a new `Index` to specify the
- * sibling to traverse after `node` is traversed.
- * Adding or removing next siblings of `node` (or previous siblings, in case
- * of reverse) is handled as expected without needing to return a new `Index`.
- *
- * Removing the children property of `parent` still results in them being
- * traversed.
- * @param {Visited} node
- * Found node.
- * @param {Visited extends UnistNode ? number | undefined : never} index
- * Index of `node` in `parent`.
- * @param {Ancestor extends UnistParent ? Ancestor | undefined : never} parent
- * Parent of `node`.
- * @returns {VisitorResult}
- * What to do next.
- *
- * An `Index` is treated as a tuple of `[CONTINUE, Index]`.
- * An `Action` is treated as a tuple of `[Action]`.
- *
- * Passing a tuple back only makes sense if the `Action` is `SKIP`.
- * When the `Action` is `EXIT`, that action can be returned.
- * When the `Action` is `CONTINUE`, `Index` can be returned.
- * @template {UnistNode} [Visited=UnistNode]
- * Visited node type.
- * @template {UnistParent} [Ancestor=UnistParent]
- * Ancestor type.
- */
- /**
- * @typedef {Visitor<Visited, Parent<Ancestor, Visited>>} BuildVisitorFromMatch
- * Build a typed `Visitor` function from a node and all possible parents.
- *
- * It will infer which values are passed as `node` and which as `parent`.
- * @template {UnistNode} Visited
- * Node type.
- * @template {UnistParent} Ancestor
- * Parent type.
- */
- /**
- * @typedef {(
- * BuildVisitorFromMatch<
- * Matches<Descendant, Check>,
- * Extract<Descendant, UnistParent>
- * >
- * )} BuildVisitorFromDescendants
- * Build a typed `Visitor` function from a list of descendants and a test.
- *
- * It will infer which values are passed as `node` and which as `parent`.
- * @template {UnistNode} Descendant
- * Node type.
- * @template {Test} Check
- * Test type.
- */
- /**
- * @typedef {(
- * BuildVisitorFromDescendants<
- * InclusiveDescendant<Tree>,
- * Check
- * >
- * )} BuildVisitor
- * Build a typed `Visitor` function from a tree and a test.
- *
- * It will infer which values are passed as `node` and which as `parent`.
- * @template {UnistNode} [Tree=UnistNode]
- * Node type.
- * @template {Test} [Check=Test]
- * Test type.
- */
- import {visitParents} from 'unist-util-visit-parents'
- export {CONTINUE, EXIT, SKIP} from 'unist-util-visit-parents'
- /**
- * Visit nodes.
- *
- * This algorithm performs *depth-first* *tree traversal* in *preorder*
- * (**NLR**) or if `reverse` is given, in *reverse preorder* (**NRL**).
- *
- * You can choose for which nodes `visitor` is called by passing a `test`.
- * For complex tests, you should test yourself in `visitor`, as it will be
- * faster and will have improved type information.
- *
- * Walking the tree is an intensive task.
- * Make use of the return values of the visitor when possible.
- * Instead of walking a tree multiple times, walk it once, use `unist-util-is`
- * to check if a node matches, and then perform different operations.
- *
- * You can change the tree.
- * See `Visitor` for more info.
- *
- * @overload
- * @param {Tree} tree
- * @param {Check} check
- * @param {BuildVisitor<Tree, Check>} visitor
- * @param {boolean | null | undefined} [reverse]
- * @returns {undefined}
- *
- * @overload
- * @param {Tree} tree
- * @param {BuildVisitor<Tree>} visitor
- * @param {boolean | null | undefined} [reverse]
- * @returns {undefined}
- *
- * @param {UnistNode} tree
- * Tree to traverse.
- * @param {Visitor | Test} testOrVisitor
- * `unist-util-is`-compatible test (optional, omit to pass a visitor).
- * @param {Visitor | boolean | null | undefined} [visitorOrReverse]
- * Handle each node (when test is omitted, pass `reverse`).
- * @param {boolean | null | undefined} [maybeReverse=false]
- * Traverse in reverse preorder (NRL) instead of the default preorder (NLR).
- * @returns {undefined}
- * Nothing.
- *
- * @template {UnistNode} Tree
- * Node type.
- * @template {Test} Check
- * `unist-util-is`-compatible test.
- */
- export function visit(tree, testOrVisitor, visitorOrReverse, maybeReverse) {
- /** @type {boolean | null | undefined} */
- let reverse
- /** @type {Test} */
- let test
- /** @type {Visitor} */
- let visitor
- if (
- typeof testOrVisitor === 'function' &&
- typeof visitorOrReverse !== 'function'
- ) {
- test = undefined
- visitor = testOrVisitor
- reverse = visitorOrReverse
- } else {
- // @ts-expect-error: assume the overload with test was given.
- test = testOrVisitor
- // @ts-expect-error: assume the overload with test was given.
- visitor = visitorOrReverse
- reverse = maybeReverse
- }
- visitParents(tree, test, overload, reverse)
- /**
- * @param {UnistNode} node
- * @param {Array<UnistParent>} parents
- */
- function overload(node, parents) {
- const parent = parents[parents.length - 1]
- const index = parent ? parent.children.indexOf(node) : undefined
- return visitor(node, index, parent)
- }
- }
|