// FIXME profile adding a per-Tree TreeNode cache, validating it by
// parent pointer
/// The default maximum length of a `TreeBuffer` node.
const DefaultBufferLength = 1024;
let nextPropID = 0;
class Range {
    constructor(from, to) {
        this.from = from;
        this.to = to;
    }
}
/// Each [node type](#common.NodeType) or [individual tree](#common.Tree)
/// can have metadata associated with it in props. Instances of this
/// class represent prop names.
class NodeProp {
    /// Create a new node prop type.
    constructor(config = {}) {
        this.id = nextPropID++;
        this.perNode = !!config.perNode;
        this.deserialize = config.deserialize || (() => {
            throw new Error("This node type doesn't define a deserialize function");
        });
    }
    /// This is meant to be used with
    /// [`NodeSet.extend`](#common.NodeSet.extend) or
    /// [`LRParser.configure`](#lr.ParserConfig.props) to compute
    /// prop values for each node type in the set. Takes a [match
    /// object](#common.NodeType^match) or function that returns undefined
    /// if the node type doesn't get this prop, and the prop's value if
    /// it does.
    add(match) {
        if (this.perNode)
            throw new RangeError("Can't add per-node props to node types");
        if (typeof match != "function")
            match = NodeType.match(match);
        return (type) => {
            let result = match(type);
            return result === undefined ? null : [this, result];
        };
    }
}
/// Prop that is used to describe matching delimiters. For opening
/// delimiters, this holds an array of node names (written as a
/// space-separated string when declaring this prop in a grammar)
/// for the node types of closing delimiters that match it.
NodeProp.closedBy = new NodeProp({ deserialize: str => str.split(" ") });
/// The inverse of [`closedBy`](#common.NodeProp^closedBy). This is
/// attached to closing delimiters, holding an array of node names
/// of types of matching opening delimiters.
NodeProp.openedBy = new NodeProp({ deserialize: str => str.split(" ") });
/// Used to assign node types to groups (for example, all node
/// types that represent an expression could be tagged with an
/// `"Expression"` group).
NodeProp.group = new NodeProp({ deserialize: str => str.split(" ") });
/// The hash of the [context](#lr.ContextTracker.constructor)
/// that the node was parsed in, if any. Used to limit reuse of
/// contextual nodes.
NodeProp.contextHash = new NodeProp({ perNode: true });
/// The distance beyond the end of the node that the tokenizer
/// looked ahead for any of the tokens inside the node. (The LR
/// parser only stores this when it is larger than 25, for
/// efficiency reasons.)
NodeProp.lookAhead = new NodeProp({ perNode: true });
/// This per-node prop is used to replace a given node, or part of a
/// node, with another tree. This is useful to include trees from
/// different languages in mixed-language parsers.
NodeProp.mounted = new NodeProp({ perNode: true });
/// A mounted tree, which can be [stored](#common.NodeProp^mounted) on
/// a tree node to indicate that parts of its content are
/// represented by another tree.
class MountedTree {
    constructor(
    /// The inner tree.
    tree, 
    /// If this is null, this tree replaces the entire node (it will
    /// be included in the regular iteration instead of its host
    /// node). If not, only the given ranges are considered to be
    /// covered by this tree. This is used for trees that are mixed in
    /// a way that isn't strictly hierarchical. Such mounted trees are
    /// only entered by [`resolveInner`](#common.Tree.resolveInner)
    /// and [`enter`](#common.SyntaxNode.enter).
    overlay, 
    /// The parser used to create this subtree.
    parser) {
        this.tree = tree;
        this.overlay = overlay;
        this.parser = parser;
    }
}
const noProps = Object.create(null);
/// Each node in a syntax tree has a node type associated with it.
class NodeType {
    /// @internal
    constructor(
    /// The name of the node type. Not necessarily unique, but if the
    /// grammar was written properly, different node types with the
    /// same name within a node set should play the same semantic
    /// role.
    name, 
    /// @internal
    props, 
    /// The id of this node in its set. Corresponds to the term ids
    /// used in the parser.
    id, 
    /// @internal
    flags = 0) {
        this.name = name;
        this.props = props;
        this.id = id;
        this.flags = flags;
    }
    /// Define a node type.
    static define(spec) {
        let props = spec.props && spec.props.length ? Object.create(null) : noProps;
        let flags = (spec.top ? 1 /* Top */ : 0) | (spec.skipped ? 2 /* Skipped */ : 0) |
            (spec.error ? 4 /* Error */ : 0) | (spec.name == null ? 8 /* Anonymous */ : 0);
        let type = new NodeType(spec.name || "", props, spec.id, flags);
        if (spec.props)
            for (let src of spec.props) {
                if (!Array.isArray(src))
                    src = src(type);
                if (src) {
                    if (src[0].perNode)
                        throw new RangeError("Can't store a per-node prop on a node type");
                    props[src[0].id] = src[1];
                }
            }
        return type;
    }
    /// Retrieves a node prop for this type. Will return `undefined` if
    /// the prop isn't present on this node.
    prop(prop) { return this.props[prop.id]; }
    /// True when this is the top node of a grammar.
    get isTop() { return (this.flags & 1 /* Top */) > 0; }
    /// True when this node is produced by a skip rule.
    get isSkipped() { return (this.flags & 2 /* Skipped */) > 0; }
    /// Indicates whether this is an error node.
    get isError() { return (this.flags & 4 /* Error */) > 0; }
    /// When true, this node type doesn't correspond to a user-declared
    /// named node, for example because it is used to cache repetition.
    get isAnonymous() { return (this.flags & 8 /* Anonymous */) > 0; }
    /// Returns true when this node's name or one of its
    /// [groups](#common.NodeProp^group) matches the given string.
    is(name) {
        if (typeof name == 'string') {
            if (this.name == name)
                return true;
            let group = this.prop(NodeProp.group);
            return group ? group.indexOf(name) > -1 : false;
        }
        return this.id == name;
    }
    /// Create a function from node types to arbitrary values by
    /// specifying an object whose property names are node or
    /// [group](#common.NodeProp^group) names. Often useful with
    /// [`NodeProp.add`](#common.NodeProp.add). You can put multiple
    /// names, separated by spaces, in a single property name to map
    /// multiple node names to a single value.
    static match(map) {
        let direct = Object.create(null);
        for (let prop in map)
            for (let name of prop.split(" "))
                direct[name] = map[prop];
        return (node) => {
            for (let groups = node.prop(NodeProp.group), i = -1; i < (groups ? groups.length : 0); i++) {
                let found = direct[i < 0 ? node.name : groups[i]];
                if (found)
                    return found;
            }
        };
    }
}
/// An empty dummy node type to use when no actual type is available.
NodeType.none = new NodeType("", Object.create(null), 0, 8 /* Anonymous */);
/// A node set holds a collection of node types. It is used to
/// compactly represent trees by storing their type ids, rather than a
/// full pointer to the type object, in a numeric array. Each parser
/// [has](#lr.LRParser.nodeSet) a node set, and [tree
/// buffers](#common.TreeBuffer) can only store collections of nodes
/// from the same set. A set can have a maximum of 2**16 (65536) node
/// types in it, so that the ids fit into 16-bit typed array slots.
class NodeSet {
    /// Create a set with the given types. The `id` property of each
    /// type should correspond to its position within the array.
    constructor(
    /// The node types in this set, by id.
    types) {
        this.types = types;
        for (let i = 0; i < types.length; i++)
            if (types[i].id != i)
                throw new RangeError("Node type ids should correspond to array positions when creating a node set");
    }
    /// Create a copy of this set with some node properties added. The
    /// arguments to this method can be created with
    /// [`NodeProp.add`](#common.NodeProp.add).
    extend(...props) {
        let newTypes = [];
        for (let type of this.types) {
            let newProps = null;
            for (let source of props) {
                let add = source(type);
                if (add) {
                    if (!newProps)
                        newProps = Object.assign({}, type.props);
                    newProps[add[0].id] = add[1];
                }
            }
            newTypes.push(newProps ? new NodeType(type.name, newProps, type.id, type.flags) : type);
        }
        return new NodeSet(newTypes);
    }
}
const CachedNode = new WeakMap(), CachedInnerNode = new WeakMap();
/// Options that control iteration. Can be combined with the `|`
/// operator to enable multiple ones.
var IterMode;
(function (IterMode) {
    /// When enabled, iteration will only visit [`Tree`](#common.Tree)
    /// objects, not nodes packed into
    /// [`TreeBuffer`](#common.TreeBuffer)s.
    IterMode[IterMode["ExcludeBuffers"] = 1] = "ExcludeBuffers";
    /// Enable this to make iteration include anonymous nodes (such as
    /// the nodes that wrap repeated grammar constructs into a balanced
    /// tree).
    IterMode[IterMode["IncludeAnonymous"] = 2] = "IncludeAnonymous";
    /// By default, regular [mounted](#common.NodeProp^mounted) nodes
    /// replace their base node in iteration. Enable this to ignore them
    /// instead.
    IterMode[IterMode["IgnoreMounts"] = 4] = "IgnoreMounts";
    /// This option only applies in
    /// [`enter`](#common.SyntaxNode.enter)-style methods. It tells the
    /// library to not enter mounted overlays if one covers the given
    /// position.
    IterMode[IterMode["IgnoreOverlays"] = 8] = "IgnoreOverlays";
})(IterMode || (IterMode = {}));
/// A piece of syntax tree. There are two ways to approach these
/// trees: the way they are actually stored in memory, and the
/// convenient way.
///
/// Syntax trees are stored as a tree of `Tree` and `TreeBuffer`
/// objects. By packing detail information into `TreeBuffer` leaf
/// nodes, the representation is made a lot more memory-efficient.
///
/// However, when you want to actually work with tree nodes, this
/// representation is very awkward, so most client code will want to
/// use the [`TreeCursor`](#common.TreeCursor) or
/// [`SyntaxNode`](#common.SyntaxNode) interface instead, which provides
/// a view on some part of this data structure, and can be used to
/// move around to adjacent nodes.
class Tree {
    /// Construct a new tree. See also [`Tree.build`](#common.Tree^build).
    constructor(
    /// The type of the top node.
    type, 
    /// This node's child nodes.
    children, 
    /// The positions (offsets relative to the start of this tree) of
    /// the children.
    positions, 
    /// The total length of this tree
    length, 
    /// Per-node [node props](#common.NodeProp) to associate with this node.
    props) {
        this.type = type;
        this.children = children;
        this.positions = positions;
        this.length = length;
        /// @internal
        this.props = null;
        if (props && props.length) {
            this.props = Object.create(null);
            for (let [prop, value] of props)
                this.props[typeof prop == "number" ? prop : prop.id] = value;
        }
    }
    /// @internal
    toString() {
        let mounted = this.prop(NodeProp.mounted);
        if (mounted && !mounted.overlay)
            return mounted.tree.toString();
        let children = "";
        for (let ch of this.children) {
            let str = ch.toString();
            if (str) {
                if (children)
                    children += ",";
                children += str;
            }
        }
        return !this.type.name ? children :
            (/\W/.test(this.type.name) && !this.type.isError ? JSON.stringify(this.type.name) : this.type.name) +
                (children.length ? "(" + children + ")" : "");
    }
    /// Get a [tree cursor](#common.TreeCursor) positioned at the top of
    /// the tree. Mode can be used to [control](#common.IterMode) which
    /// nodes the cursor visits.
    cursor(mode = 0) {
        return new TreeCursor(this.topNode, mode);
    }
    /// Get a [tree cursor](#common.TreeCursor) pointing into this tree
    /// at the given position and side (see
    /// [`moveTo`](#common.TreeCursor.moveTo).
    cursorAt(pos, side = 0, mode = 0) {
        let scope = CachedNode.get(this) || this.topNode;
        let cursor = new TreeCursor(scope);
        cursor.moveTo(pos, side);
        CachedNode.set(this, cursor._tree);
        return cursor;
    }
    /// Get a [syntax node](#common.SyntaxNode) object for the top of the
    /// tree.
    get topNode() {
        return new TreeNode(this, 0, 0, null);
    }
    /// Get the [syntax node](#common.SyntaxNode) at the given position.
    /// If `side` is -1, this will move into nodes that end at the
    /// position. If 1, it'll move into nodes that start at the
    /// position. With 0, it'll only enter nodes that cover the position
    /// from both sides.
    resolve(pos, side = 0) {
        let node = resolveNode(CachedNode.get(this) || this.topNode, pos, side, false);
        CachedNode.set(this, node);
        return node;
    }
    /// Like [`resolve`](#common.Tree.resolve), but will enter
    /// [overlaid](#common.MountedTree.overlay) nodes, producing a syntax node
    /// pointing into the innermost overlaid tree at the given position
    /// (with parent links going through all parent structure, including
    /// the host trees).
    resolveInner(pos, side = 0) {
        let node = resolveNode(CachedInnerNode.get(this) || this.topNode, pos, side, true);
        CachedInnerNode.set(this, node);
        return node;
    }
    /// Iterate over the tree and its children, calling `enter` for any
    /// node that touches the `from`/`to` region (if given) before
    /// running over such a node's children, and `leave` (if given) when
    /// leaving the node. When `enter` returns `false`, that node will
    /// not have its children iterated over (or `leave` called).
    iterate(spec) {
        let { enter, leave, from = 0, to = this.length } = spec;
        for (let c = this.cursor((spec.mode || 0) | IterMode.IncludeAnonymous);;) {
            let entered = false;
            if (c.from <= to && c.to >= from && (c.type.isAnonymous || enter(c) !== false)) {
                if (c.firstChild())
                    continue;
                entered = true;
            }
            for (;;) {
                if (entered && leave && !c.type.isAnonymous)
                    leave(c);
                if (c.nextSibling())
                    break;
                if (!c.parent())
                    return;
                entered = true;
            }
        }
    }
    /// Get the value of the given [node prop](#common.NodeProp) for this
    /// node. Works with both per-node and per-type props.
    prop(prop) {
        return !prop.perNode ? this.type.prop(prop) : this.props ? this.props[prop.id] : undefined;
    }
    /// Returns the node's [per-node props](#common.NodeProp.perNode) in a
    /// format that can be passed to the [`Tree`](#common.Tree)
    /// constructor.
    get propValues() {
        let result = [];
        if (this.props)
            for (let id in this.props)
                result.push([+id, this.props[id]]);
        return result;
    }
    /// Balance the direct children of this tree, producing a copy of
    /// which may have children grouped into subtrees with type
    /// [`NodeType.none`](#common.NodeType^none).
    balance(config = {}) {
        return this.children.length <= 8 /* BranchFactor */ ? this :
            balanceRange(NodeType.none, this.children, this.positions, 0, this.children.length, 0, this.length, (children, positions, length) => new Tree(this.type, children, positions, length, this.propValues), config.makeTree || ((children, positions, length) => new Tree(NodeType.none, children, positions, length)));
    }
    /// Build a tree from a postfix-ordered buffer of node information,
    /// or a cursor over such a buffer.
    static build(data) { return buildTree(data); }
}
/// The empty tree
Tree.empty = new Tree(NodeType.none, [], [], 0);
class FlatBufferCursor {
    constructor(buffer, index) {
        this.buffer = buffer;
        this.index = index;
    }
    get id() { return this.buffer[this.index - 4]; }
    get start() { return this.buffer[this.index - 3]; }
    get end() { return this.buffer[this.index - 2]; }
    get size() { return this.buffer[this.index - 1]; }
    get pos() { return this.index; }
    next() { this.index -= 4; }
    fork() { return new FlatBufferCursor(this.buffer, this.index); }
}
/// Tree buffers contain (type, start, end, endIndex) quads for each
/// node. In such a buffer, nodes are stored in prefix order (parents
/// before children, with the endIndex of the parent indicating which
/// children belong to it).
class TreeBuffer {
    /// Create a tree buffer.
    constructor(
    /// The buffer's content.
    buffer, 
    /// The total length of the group of nodes in the buffer.
    length, 
    /// The node set used in this buffer.
    set) {
        this.buffer = buffer;
        this.length = length;
        this.set = set;
    }
    /// @internal
    get type() { return NodeType.none; }
    /// @internal
    toString() {
        let result = [];
        for (let index = 0; index < this.buffer.length;) {
            result.push(this.childString(index));
            index = this.buffer[index + 3];
        }
        return result.join(",");
    }
    /// @internal
    childString(index) {
        let id = this.buffer[index], endIndex = this.buffer[index + 3];
        let type = this.set.types[id], result = type.name;
        if (/\W/.test(result) && !type.isError)
            result = JSON.stringify(result);
        index += 4;
        if (endIndex == index)
            return result;
        let children = [];
        while (index < endIndex) {
            children.push(this.childString(index));
            index = this.buffer[index + 3];
        }
        return result + "(" + children.join(",") + ")";
    }
    /// @internal
    findChild(startIndex, endIndex, dir, pos, side) {
        let { buffer } = this, pick = -1;
        for (let i = startIndex; i != endIndex; i = buffer[i + 3]) {
            if (checkSide(side, pos, buffer[i + 1], buffer[i + 2])) {
                pick = i;
                if (dir > 0)
                    break;
            }
        }
        return pick;
    }
    /// @internal
    slice(startI, endI, from, to) {
        let b = this.buffer;
        let copy = new Uint16Array(endI - startI);
        for (let i = startI, j = 0; i < endI;) {
            copy[j++] = b[i++];
            copy[j++] = b[i++] - from;
            copy[j++] = b[i++] - from;
            copy[j++] = b[i++] - startI;
        }
        return new TreeBuffer(copy, to - from, this.set);
    }
}
function checkSide(side, pos, from, to) {
    switch (side) {
        case -2 /* Before */: return from < pos;
        case -1 /* AtOrBefore */: return to >= pos && from < pos;
        case 0 /* Around */: return from < pos && to > pos;
        case 1 /* AtOrAfter */: return from <= pos && to > pos;
        case 2 /* After */: return to > pos;
        case 4 /* DontCare */: return true;
    }
}
function enterUnfinishedNodesBefore(node, pos) {
    let scan = node.childBefore(pos);
    while (scan) {
        let last = scan.lastChild;
        if (!last || last.to != scan.to)
            break;
        if (last.type.isError && last.from == last.to) {
            node = scan;
            scan = last.prevSibling;
        }
        else {
            scan = last;
        }
    }
    return node;
}
function resolveNode(node, pos, side, overlays) {
    var _a;
    // Move up to a node that actually holds the position, if possible
    while (node.from == node.to ||
        (side < 1 ? node.from >= pos : node.from > pos) ||
        (side > -1 ? node.to <= pos : node.to < pos)) {
        let parent = !overlays && node instanceof TreeNode && node.index < 0 ? null : node.parent;
        if (!parent)
            return node;
        node = parent;
    }
    let mode = overlays ? 0 : IterMode.IgnoreOverlays;
    // Must go up out of overlays when those do not overlap with pos
    if (overlays)
        for (let scan = node, parent = scan.parent; parent; scan = parent, parent = scan.parent) {
            if (scan instanceof TreeNode && scan.index < 0 && ((_a = parent.enter(pos, side, mode)) === null || _a === void 0 ? void 0 : _a.from) != scan.from)
                node = parent;
        }
    for (;;) {
        let inner = node.enter(pos, side, mode);
        if (!inner)
            return node;
        node = inner;
    }
}
class TreeNode {
    constructor(_tree, from, 
    // Index in parent node, set to -1 if the node is not a direct child of _parent.node (overlay)
    index, _parent) {
        this._tree = _tree;
        this.from = from;
        this.index = index;
        this._parent = _parent;
    }
    get type() { return this._tree.type; }
    get name() { return this._tree.type.name; }
    get to() { return this.from + this._tree.length; }
    nextChild(i, dir, pos, side, mode = 0) {
        for (let parent = this;;) {
            for (let { children, positions } = parent._tree, e = dir > 0 ? children.length : -1; i != e; i += dir) {
                let next = children[i], start = positions[i] + parent.from;
                if (!checkSide(side, pos, start, start + next.length))
                    continue;
                if (next instanceof TreeBuffer) {
                    if (mode & IterMode.ExcludeBuffers)
                        continue;
                    let index = next.findChild(0, next.buffer.length, dir, pos - start, side);
                    if (index > -1)
                        return new BufferNode(new BufferContext(parent, next, i, start), null, index);
                }
                else if ((mode & IterMode.IncludeAnonymous) || (!next.type.isAnonymous || hasChild(next))) {
                    let mounted;
                    if (!(mode & IterMode.IgnoreMounts) &&
                        next.props && (mounted = next.prop(NodeProp.mounted)) && !mounted.overlay)
                        return new TreeNode(mounted.tree, start, i, parent);
                    let inner = new TreeNode(next, start, i, parent);
                    return (mode & IterMode.IncludeAnonymous) || !inner.type.isAnonymous ? inner
                        : inner.nextChild(dir < 0 ? next.children.length - 1 : 0, dir, pos, side);
                }
            }
            if ((mode & IterMode.IncludeAnonymous) || !parent.type.isAnonymous)
                return null;
            if (parent.index >= 0)
                i = parent.index + dir;
            else
                i = dir < 0 ? -1 : parent._parent._tree.children.length;
            parent = parent._parent;
            if (!parent)
                return null;
        }
    }
    get firstChild() { return this.nextChild(0, 1, 0, 4 /* DontCare */); }
    get lastChild() { return this.nextChild(this._tree.children.length - 1, -1, 0, 4 /* DontCare */); }
    childAfter(pos) { return this.nextChild(0, 1, pos, 2 /* After */); }
    childBefore(pos) { return this.nextChild(this._tree.children.length - 1, -1, pos, -2 /* Before */); }
    enter(pos, side, mode = 0) {
        let mounted;
        if (!(mode & IterMode.IgnoreOverlays) && (mounted = this._tree.prop(NodeProp.mounted)) && mounted.overlay) {
            let rPos = pos - this.from;
            for (let { from, to } of mounted.overlay) {
                if ((side > 0 ? from <= rPos : from < rPos) &&
                    (side < 0 ? to >= rPos : to > rPos))
                    return new TreeNode(mounted.tree, mounted.overlay[0].from + this.from, -1, this);
            }
        }
        return this.nextChild(0, 1, pos, side, mode);
    }
    nextSignificantParent() {
        let val = this;
        while (val.type.isAnonymous && val._parent)
            val = val._parent;
        return val;
    }
    get parent() {
        return this._parent ? this._parent.nextSignificantParent() : null;
    }
    get nextSibling() {
        return this._parent && this.index >= 0 ? this._parent.nextChild(this.index + 1, 1, 0, 4 /* DontCare */) : null;
    }
    get prevSibling() {
        return this._parent && this.index >= 0 ? this._parent.nextChild(this.index - 1, -1, 0, 4 /* DontCare */) : null;
    }
    cursor(mode = 0) { return new TreeCursor(this, mode); }
    get tree() { return this._tree; }
    toTree() { return this._tree; }
    resolve(pos, side = 0) {
        return resolveNode(this, pos, side, false);
    }
    resolveInner(pos, side = 0) {
        return resolveNode(this, pos, side, true);
    }
    enterUnfinishedNodesBefore(pos) { return enterUnfinishedNodesBefore(this, pos); }
    getChild(type, before = null, after = null) {
        let r = getChildren(this, type, before, after);
        return r.length ? r[0] : null;
    }
    getChildren(type, before = null, after = null) {
        return getChildren(this, type, before, after);
    }
    /// @internal
    toString() { return this._tree.toString(); }
    get node() { return this; }
    matchContext(context) { return matchNodeContext(this, context); }
}
function getChildren(node, type, before, after) {
    let cur = node.cursor(), result = [];
    if (!cur.firstChild())
        return result;
    if (before != null)
        while (!cur.type.is(before))
            if (!cur.nextSibling())
                return result;
    for (;;) {
        if (after != null && cur.type.is(after))
            return result;
        if (cur.type.is(type))
            result.push(cur.node);
        if (!cur.nextSibling())
            return after == null ? result : [];
    }
}
function matchNodeContext(node, context, i = context.length - 1) {
    for (let p = node.parent; i >= 0; p = p.parent) {
        if (!p)
            return false;
        if (!p.type.isAnonymous) {
            if (context[i] && context[i] != p.name)
                return false;
            i--;
        }
    }
    return true;
}
class BufferContext {
    constructor(parent, buffer, index, start) {
        this.parent = parent;
        this.buffer = buffer;
        this.index = index;
        this.start = start;
    }
}
class BufferNode {
    constructor(context, _parent, index) {
        this.context = context;
        this._parent = _parent;
        this.index = index;
        this.type = context.buffer.set.types[context.buffer.buffer[index]];
    }
    get name() { return this.type.name; }
    get from() { return this.context.start + this.context.buffer.buffer[this.index + 1]; }
    get to() { return this.context.start + this.context.buffer.buffer[this.index + 2]; }
    child(dir, pos, side) {
        let { buffer } = this.context;
        let index = buffer.findChild(this.index + 4, buffer.buffer[this.index + 3], dir, pos - this.context.start, side);
        return index < 0 ? null : new BufferNode(this.context, this, index);
    }
    get firstChild() { return this.child(1, 0, 4 /* DontCare */); }
    get lastChild() { return this.child(-1, 0, 4 /* DontCare */); }
    childAfter(pos) { return this.child(1, pos, 2 /* After */); }
    childBefore(pos) { return this.child(-1, pos, -2 /* Before */); }
    enter(pos, side, mode = 0) {
        if (mode & IterMode.ExcludeBuffers)
            return null;
        let { buffer } = this.context;
        let index = buffer.findChild(this.index + 4, buffer.buffer[this.index + 3], side > 0 ? 1 : -1, pos - this.context.start, side);
        return index < 0 ? null : new BufferNode(this.context, this, index);
    }
    get parent() {
        return this._parent || this.context.parent.nextSignificantParent();
    }
    externalSibling(dir) {
        return this._parent ? null : this.context.parent.nextChild(this.context.index + dir, dir, 0, 4 /* DontCare */);
    }
    get nextSibling() {
        let { buffer } = this.context;
        let after = buffer.buffer[this.index + 3];
        if (after < (this._parent ? buffer.buffer[this._parent.index + 3] : buffer.buffer.length))
            return new BufferNode(this.context, this._parent, after);
        return this.externalSibling(1);
    }
    get prevSibling() {
        let { buffer } = this.context;
        let parentStart = this._parent ? this._parent.index + 4 : 0;
        if (this.index == parentStart)
            return this.externalSibling(-1);
        return new BufferNode(this.context, this._parent, buffer.findChild(parentStart, this.index, -1, 0, 4 /* DontCare */));
    }
    cursor(mode = 0) { return new TreeCursor(this, mode); }
    get tree() { return null; }
    toTree() {
        let children = [], positions = [];
        let { buffer } = this.context;
        let startI = this.index + 4, endI = buffer.buffer[this.index + 3];
        if (endI > startI) {
            let from = buffer.buffer[this.index + 1], to = buffer.buffer[this.index + 2];
            children.push(buffer.slice(startI, endI, from, to));
            positions.push(0);
        }
        return new Tree(this.type, children, positions, this.to - this.from);
    }
    resolve(pos, side = 0) {
        return resolveNode(this, pos, side, false);
    }
    resolveInner(pos, side = 0) {
        return resolveNode(this, pos, side, true);
    }
    enterUnfinishedNodesBefore(pos) { return enterUnfinishedNodesBefore(this, pos); }
    /// @internal
    toString() { return this.context.buffer.childString(this.index); }
    getChild(type, before = null, after = null) {
        let r = getChildren(this, type, before, after);
        return r.length ? r[0] : null;
    }
    getChildren(type, before = null, after = null) {
        return getChildren(this, type, before, after);
    }
    get node() { return this; }
    matchContext(context) { return matchNodeContext(this, context); }
}
/// A tree cursor object focuses on a given node in a syntax tree, and
/// allows you to move to adjacent nodes.
class TreeCursor {
    /// @internal
    constructor(node, 
    /// @internal
    mode = 0) {
        this.mode = mode;
        /// @internal
        this.buffer = null;
        this.stack = [];
        /// @internal
        this.index = 0;
        this.bufferNode = null;
        if (node instanceof TreeNode) {
            this.yieldNode(node);
        }
        else {
            this._tree = node.context.parent;
            this.buffer = node.context;
            for (let n = node._parent; n; n = n._parent)
                this.stack.unshift(n.index);
            this.bufferNode = node;
            this.yieldBuf(node.index);
        }
    }
    /// Shorthand for `.type.name`.
    get name() { return this.type.name; }
    yieldNode(node) {
        if (!node)
            return false;
        this._tree = node;
        this.type = node.type;
        this.from = node.from;
        this.to = node.to;
        return true;
    }
    yieldBuf(index, type) {
        this.index = index;
        let { start, buffer } = this.buffer;
        this.type = type || buffer.set.types[buffer.buffer[index]];
        this.from = start + buffer.buffer[index + 1];
        this.to = start + buffer.buffer[index + 2];
        return true;
    }
    yield(node) {
        if (!node)
            return false;
        if (node instanceof TreeNode) {
            this.buffer = null;
            return this.yieldNode(node);
        }
        this.buffer = node.context;
        return this.yieldBuf(node.index, node.type);
    }
    /// @internal
    toString() {
        return this.buffer ? this.buffer.buffer.childString(this.index) : this._tree.toString();
    }
    /// @internal
    enterChild(dir, pos, side) {
        if (!this.buffer)
            return this.yield(this._tree.nextChild(dir < 0 ? this._tree._tree.children.length - 1 : 0, dir, pos, side, this.mode));
        let { buffer } = this.buffer;
        let index = buffer.findChild(this.index + 4, buffer.buffer[this.index + 3], dir, pos - this.buffer.start, side);
        if (index < 0)
            return false;
        this.stack.push(this.index);
        return this.yieldBuf(index);
    }
    /// Move the cursor to this node's first child. When this returns
    /// false, the node has no child, and the cursor has not been moved.
    firstChild() { return this.enterChild(1, 0, 4 /* DontCare */); }
    /// Move the cursor to this node's last child.
    lastChild() { return this.enterChild(-1, 0, 4 /* DontCare */); }
    /// Move the cursor to the first child that ends after `pos`.
    childAfter(pos) { return this.enterChild(1, pos, 2 /* After */); }
    /// Move to the last child that starts before `pos`.
    childBefore(pos) { return this.enterChild(-1, pos, -2 /* Before */); }
    /// Move the cursor to the child around `pos`. If side is -1 the
    /// child may end at that position, when 1 it may start there. This
    /// will also enter [overlaid](#common.MountedTree.overlay)
    /// [mounted](#common.NodeProp^mounted) trees unless `overlays` is
    /// set to false.
    enter(pos, side, mode = this.mode) {
        if (!this.buffer)
            return this.yield(this._tree.enter(pos, side, mode));
        return mode & IterMode.ExcludeBuffers ? false : this.enterChild(1, pos, side);
    }
    /// Move to the node's parent node, if this isn't the top node.
    parent() {
        if (!this.buffer)
            return this.yieldNode((this.mode & IterMode.IncludeAnonymous) ? this._tree._parent : this._tree.parent);
        if (this.stack.length)
            return this.yieldBuf(this.stack.pop());
        let parent = (this.mode & IterMode.IncludeAnonymous) ? this.buffer.parent : this.buffer.parent.nextSignificantParent();
        this.buffer = null;
        return this.yieldNode(parent);
    }
    /// @internal
    sibling(dir) {
        if (!this.buffer)
            return !this._tree._parent ? false
                : this.yield(this._tree.index < 0 ? null
                    : this._tree._parent.nextChild(this._tree.index + dir, dir, 0, 4 /* DontCare */, this.mode));
        let { buffer } = this.buffer, d = this.stack.length - 1;
        if (dir < 0) {
            let parentStart = d < 0 ? 0 : this.stack[d] + 4;
            if (this.index != parentStart)
                return this.yieldBuf(buffer.findChild(parentStart, this.index, -1, 0, 4 /* DontCare */));
        }
        else {
            let after = buffer.buffer[this.index + 3];
            if (after < (d < 0 ? buffer.buffer.length : buffer.buffer[this.stack[d] + 3]))
                return this.yieldBuf(after);
        }
        return d < 0 ? this.yield(this.buffer.parent.nextChild(this.buffer.index + dir, dir, 0, 4 /* DontCare */, this.mode)) : false;
    }
    /// Move to this node's next sibling, if any.
    nextSibling() { return this.sibling(1); }
    /// Move to this node's previous sibling, if any.
    prevSibling() { return this.sibling(-1); }
    atLastNode(dir) {
        let index, parent, { buffer } = this;
        if (buffer) {
            if (dir > 0) {
                if (this.index < buffer.buffer.buffer.length)
                    return false;
            }
            else {
                for (let i = 0; i < this.index; i++)
                    if (buffer.buffer.buffer[i + 3] < this.index)
                        return false;
            }
            ({ index, parent } = buffer);
        }
        else {
            ({ index, _parent: parent } = this._tree);
        }
        for (; parent; { index, _parent: parent } = parent) {
            if (index > -1)
                for (let i = index + dir, e = dir < 0 ? -1 : parent._tree.children.length; i != e; i += dir) {
                    let child = parent._tree.children[i];
                    if ((this.mode & IterMode.IncludeAnonymous) ||
                        child instanceof TreeBuffer ||
                        !child.type.isAnonymous ||
                        hasChild(child))
                        return false;
                }
        }
        return true;
    }
    move(dir, enter) {
        if (enter && this.enterChild(dir, 0, 4 /* DontCare */))
            return true;
        for (;;) {
            if (this.sibling(dir))
                return true;
            if (this.atLastNode(dir) || !this.parent())
                return false;
        }
    }
    /// Move to the next node in a
    /// [pre-order](https://en.wikipedia.org/wiki/Tree_traversal#Pre-order_(NLR))
    /// traversal, going from a node to its first child or, if the
    /// current node is empty or `enter` is false, its next sibling or
    /// the next sibling of the first parent node that has one.
    next(enter = true) { return this.move(1, enter); }
    /// Move to the next node in a last-to-first pre-order traveral. A
    /// node is followed by its last child or, if it has none, its
    /// previous sibling or the previous sibling of the first parent
    /// node that has one.
    prev(enter = true) { return this.move(-1, enter); }
    /// Move the cursor to the innermost node that covers `pos`. If
    /// `side` is -1, it will enter nodes that end at `pos`. If it is 1,
    /// it will enter nodes that start at `pos`.
    moveTo(pos, side = 0) {
        // Move up to a node that actually holds the position, if possible
        while (this.from == this.to ||
            (side < 1 ? this.from >= pos : this.from > pos) ||
            (side > -1 ? this.to <= pos : this.to < pos))
            if (!this.parent())
                break;
        // Then scan down into child nodes as far as possible
        while (this.enterChild(1, pos, side)) { }
        return this;
    }
    /// Get a [syntax node](#common.SyntaxNode) at the cursor's current
    /// position.
    get node() {
        if (!this.buffer)
            return this._tree;
        let cache = this.bufferNode, result = null, depth = 0;
        if (cache && cache.context == this.buffer) {
            scan: for (let index = this.index, d = this.stack.length; d >= 0;) {
                for (let c = cache; c; c = c._parent)
                    if (c.index == index) {
                        if (index == this.index)
                            return c;
                        result = c;
                        depth = d + 1;
                        break scan;
                    }
                index = this.stack[--d];
            }
        }
        for (let i = depth; i < this.stack.length; i++)
            result = new BufferNode(this.buffer, result, this.stack[i]);
        return this.bufferNode = new BufferNode(this.buffer, result, this.index);
    }
    /// Get the [tree](#common.Tree) that represents the current node, if
    /// any. Will return null when the node is in a [tree
    /// buffer](#common.TreeBuffer).
    get tree() {
        return this.buffer ? null : this._tree._tree;
    }
    /// Iterate over the current node and all its descendants, calling
    /// `enter` when entering a node and `leave`, if given, when leaving
    /// one. When `enter` returns `false`, any children of that node are
    /// skipped, and `leave` isn't called for it.
    iterate(enter, leave) {
        for (let depth = 0;;) {
            let mustLeave = false;
            if (this.type.isAnonymous || enter(this) !== false) {
                if (this.firstChild()) {
                    depth++;
                    continue;
                }
                if (!this.type.isAnonymous)
                    mustLeave = true;
            }
            for (;;) {
                if (mustLeave && leave)
                    leave(this);
                mustLeave = this.type.isAnonymous;
                if (this.nextSibling())
                    break;
                if (!depth)
                    return;
                this.parent();
                depth--;
                mustLeave = true;
            }
        }
    }
    /// Test whether the current node matches a given context—a sequence
    /// of direct parent node names. Empty strings in the context array
    /// are treated as wildcards.
    matchContext(context) {
        if (!this.buffer)
            return matchNodeContext(this.node, context);
        let { buffer } = this.buffer, { types } = buffer.set;
        for (let i = context.length - 1, d = this.stack.length - 1; i >= 0; d--) {
            if (d < 0)
                return matchNodeContext(this.node, context, i);
            let type = types[buffer.buffer[this.stack[d]]];
            if (!type.isAnonymous) {
                if (context[i] && context[i] != type.name)
                    return false;
                i--;
            }
        }
        return true;
    }
}
function hasChild(tree) {
    return tree.children.some(ch => ch instanceof TreeBuffer || !ch.type.isAnonymous || hasChild(ch));
}
function buildTree(data) {
    var _a;
    let { buffer, nodeSet, maxBufferLength = DefaultBufferLength, reused = [], minRepeatType = nodeSet.types.length } = data;
    let cursor = Array.isArray(buffer) ? new FlatBufferCursor(buffer, buffer.length) : buffer;
    let types = nodeSet.types;
    let contextHash = 0, lookAhead = 0;
    function takeNode(parentStart, minPos, children, positions, inRepeat) {
        let { id, start, end, size } = cursor;
        let lookAheadAtStart = lookAhead;
        while (size < 0) {
            cursor.next();
            if (size == -1 /* Reuse */) {
                let node = reused[id];
                children.push(node);
                positions.push(start - parentStart);
                return;
            }
            else if (size == -3 /* ContextChange */) { // Context change
                contextHash = id;
                return;
            }
            else if (size == -4 /* LookAhead */) {
                lookAhead = id;
                return;
            }
            else {
                throw new RangeError(`Unrecognized record size: ${size}`);
            }
        }
        let type = types[id], node, buffer;
        let startPos = start - parentStart;
        if (end - start <= maxBufferLength && (buffer = findBufferSize(cursor.pos - minPos, inRepeat))) {
            // Small enough for a buffer, and no reused nodes inside
            let data = new Uint16Array(buffer.size - buffer.skip);
            let endPos = cursor.pos - buffer.size, index = data.length;
            while (cursor.pos > endPos)
                index = copyToBuffer(buffer.start, data, index);
            node = new TreeBuffer(data, end - buffer.start, nodeSet);
            startPos = buffer.start - parentStart;
        }
        else { // Make it a node
            let endPos = cursor.pos - size;
            cursor.next();
            let localChildren = [], localPositions = [];
            let localInRepeat = id >= minRepeatType ? id : -1;
            let lastGroup = 0, lastEnd = end;
            while (cursor.pos > endPos) {
                if (localInRepeat >= 0 && cursor.id == localInRepeat && cursor.size >= 0) {
                    if (cursor.end <= lastEnd - maxBufferLength) {
                        makeRepeatLeaf(localChildren, localPositions, start, lastGroup, cursor.end, lastEnd, localInRepeat, lookAheadAtStart);
                        lastGroup = localChildren.length;
                        lastEnd = cursor.end;
                    }
                    cursor.next();
                }
                else {
                    takeNode(start, endPos, localChildren, localPositions, localInRepeat);
                }
            }
            if (localInRepeat >= 0 && lastGroup > 0 && lastGroup < localChildren.length)
                makeRepeatLeaf(localChildren, localPositions, start, lastGroup, start, lastEnd, localInRepeat, lookAheadAtStart);
            localChildren.reverse();
            localPositions.reverse();
            if (localInRepeat > -1 && lastGroup > 0) {
                let make = makeBalanced(type);
                node = balanceRange(type, localChildren, localPositions, 0, localChildren.length, 0, end - start, make, make);
            }
            else {
                node = makeTree(type, localChildren, localPositions, end - start, lookAheadAtStart - end);
            }
        }
        children.push(node);
        positions.push(startPos);
    }
    function makeBalanced(type) {
        return (children, positions, length) => {
            let lookAhead = 0, lastI = children.length - 1, last, lookAheadProp;
            if (lastI >= 0 && (last = children[lastI]) instanceof Tree) {
                if (!lastI && last.type == type && last.length == length)
                    return last;
                if (lookAheadProp = last.prop(NodeProp.lookAhead))
                    lookAhead = positions[lastI] + last.length + lookAheadProp;
            }
            return makeTree(type, children, positions, length, lookAhead);
        };
    }
    function makeRepeatLeaf(children, positions, base, i, from, to, type, lookAhead) {
        let localChildren = [], localPositions = [];
        while (children.length > i) {
            localChildren.push(children.pop());
            localPositions.push(positions.pop() + base - from);
        }
        children.push(makeTree(nodeSet.types[type], localChildren, localPositions, to - from, lookAhead - to));
        positions.push(from - base);
    }
    function makeTree(type, children, positions, length, lookAhead = 0, props) {
        if (contextHash) {
            let pair = [NodeProp.contextHash, contextHash];
            props = props ? [pair].concat(props) : [pair];
        }
        if (lookAhead > 25) {
            let pair = [NodeProp.lookAhead, lookAhead];
            props = props ? [pair].concat(props) : [pair];
        }
        return new Tree(type, children, positions, length, props);
    }
    function findBufferSize(maxSize, inRepeat) {
        // Scan through the buffer to find previous siblings that fit
        // together in a TreeBuffer, and don't contain any reused nodes
        // (which can't be stored in a buffer).
        // If `inRepeat` is > -1, ignore node boundaries of that type for
        // nesting, but make sure the end falls either at the start
        // (`maxSize`) or before such a node.
        let fork = cursor.fork();
        let size = 0, start = 0, skip = 0, minStart = fork.end - maxBufferLength;
        let result = { size: 0, start: 0, skip: 0 };
        scan: for (let minPos = fork.pos - maxSize; fork.pos > minPos;) {
            let nodeSize = fork.size;
            // Pretend nested repeat nodes of the same type don't exist
            if (fork.id == inRepeat && nodeSize >= 0) {
                // Except that we store the current state as a valid return
                // value.
                result.size = size;
                result.start = start;
                result.skip = skip;
                skip += 4;
                size += 4;
                fork.next();
                continue;
            }
            let startPos = fork.pos - nodeSize;
            if (nodeSize < 0 || startPos < minPos || fork.start < minStart)
                break;
            let localSkipped = fork.id >= minRepeatType ? 4 : 0;
            let nodeStart = fork.start;
            fork.next();
            while (fork.pos > startPos) {
                if (fork.size < 0) {
                    if (fork.size == -3 /* ContextChange */)
                        localSkipped += 4;
                    else
                        break scan;
                }
                else if (fork.id >= minRepeatType) {
                    localSkipped += 4;
                }
                fork.next();
            }
            start = nodeStart;
            size += nodeSize;
            skip += localSkipped;
        }
        if (inRepeat < 0 || size == maxSize) {
            result.size = size;
            result.start = start;
            result.skip = skip;
        }
        return result.size > 4 ? result : undefined;
    }
    function copyToBuffer(bufferStart, buffer, index) {
        let { id, start, end, size } = cursor;
        cursor.next();
        if (size >= 0 && id < minRepeatType) {
            let startIndex = index;
            if (size > 4) {
                let endPos = cursor.pos - (size - 4);
                while (cursor.pos > endPos)
                    index = copyToBuffer(bufferStart, buffer, index);
            }
            buffer[--index] = startIndex;
            buffer[--index] = end - bufferStart;
            buffer[--index] = start - bufferStart;
            buffer[--index] = id;
        }
        else if (size == -3 /* ContextChange */) {
            contextHash = id;
        }
        else if (size == -4 /* LookAhead */) {
            lookAhead = id;
        }
        return index;
    }
    let children = [], positions = [];
    while (cursor.pos > 0)
        takeNode(data.start || 0, data.bufferStart || 0, children, positions, -1);
    let length = (_a = data.length) !== null && _a !== void 0 ? _a : (children.length ? positions[0] + children[0].length : 0);
    return new Tree(types[data.topID], children.reverse(), positions.reverse(), length);
}
const nodeSizeCache = new WeakMap;
function nodeSize(balanceType, node) {
    if (!balanceType.isAnonymous || node instanceof TreeBuffer || node.type != balanceType)
        return 1;
    let size = nodeSizeCache.get(node);
    if (size == null) {
        size = 1;
        for (let child of node.children) {
            if (child.type != balanceType || !(child instanceof Tree)) {
                size = 1;
                break;
            }
            size += nodeSize(balanceType, child);
        }
        nodeSizeCache.set(node, size);
    }
    return size;
}
function balanceRange(
// The type the balanced tree's inner nodes.
balanceType, 
// The direct children and their positions
children, positions, 
// The index range in children/positions to use
from, to, 
// The start position of the nodes, relative to their parent.
start, 
// Length of the outer node
length, 
// Function to build the top node of the balanced tree
mkTop, 
// Function to build internal nodes for the balanced tree
mkTree) {
    let total = 0;
    for (let i = from; i < to; i++)
        total += nodeSize(balanceType, children[i]);
    let maxChild = Math.ceil((total * 1.5) / 8 /* BranchFactor */);
    let localChildren = [], localPositions = [];
    function divide(children, positions, from, to, offset) {
        for (let i = from; i < to;) {
            let groupFrom = i, groupStart = positions[i], groupSize = nodeSize(balanceType, children[i]);
            i++;
            for (; i < to; i++) {
                let nextSize = nodeSize(balanceType, children[i]);
                if (groupSize + nextSize >= maxChild)
                    break;
                groupSize += nextSize;
            }
            if (i == groupFrom + 1) {
                if (groupSize > maxChild) {
                    let only = children[groupFrom]; // Only trees can have a size > 1
                    divide(only.children, only.positions, 0, only.children.length, positions[groupFrom] + offset);
                    continue;
                }
                localChildren.push(children[groupFrom]);
            }
            else {
                let length = positions[i - 1] + children[i - 1].length - groupStart;
                localChildren.push(balanceRange(balanceType, children, positions, groupFrom, i, groupStart, length, null, mkTree));
            }
            localPositions.push(groupStart + offset - start);
        }
    }
    divide(children, positions, from, to, 0);
    return (mkTop || mkTree)(localChildren, localPositions, length);
}
/// Provides a way to associate values with pieces of trees. As long
/// as that part of the tree is reused, the associated values can be
/// retrieved from an updated tree.
class NodeWeakMap {
    constructor() {
        this.map = new WeakMap();
    }
    setBuffer(buffer, index, value) {
        let inner = this.map.get(buffer);
        if (!inner)
            this.map.set(buffer, inner = new Map);
        inner.set(index, value);
    }
    getBuffer(buffer, index) {
        let inner = this.map.get(buffer);
        return inner && inner.get(index);
    }
    /// Set the value for this syntax node.
    set(node, value) {
        if (node instanceof BufferNode)
            this.setBuffer(node.context.buffer, node.index, value);
        else if (node instanceof TreeNode)
            this.map.set(node.tree, value);
    }
    /// Retrieve value for this syntax node, if it exists in the map.
    get(node) {
        return node instanceof BufferNode ? this.getBuffer(node.context.buffer, node.index)
            : node instanceof TreeNode ? this.map.get(node.tree) : undefined;
    }
    /// Set the value for the node that a cursor currently points to.
    cursorSet(cursor, value) {
        if (cursor.buffer)
            this.setBuffer(cursor.buffer.buffer, cursor.index, value);
        else
            this.map.set(cursor.tree, value);
    }
    /// Retrieve the value for the node that a cursor currently points
    /// to.
    cursorGet(cursor) {
        return cursor.buffer ? this.getBuffer(cursor.buffer.buffer, cursor.index) : this.map.get(cursor.tree);
    }
}

/// Tree fragments are used during [incremental
/// parsing](#common.Parser.startParse) to track parts of old trees
/// that can be reused in a new parse. An array of fragments is used
/// to track regions of an old tree whose nodes might be reused in new
/// parses. Use the static
/// [`applyChanges`](#common.TreeFragment^applyChanges) method to
/// update fragments for document changes.
class TreeFragment {
    /// Construct a tree fragment. You'll usually want to use
    /// [`addTree`](#common.TreeFragment^addTree) and
    /// [`applyChanges`](#common.TreeFragment^applyChanges) instead of
    /// calling this directly.
    constructor(
    /// The start of the unchanged range pointed to by this fragment.
    /// This refers to an offset in the _updated_ document (as opposed
    /// to the original tree).
    from, 
    /// The end of the unchanged range.
    to, 
    /// The tree that this fragment is based on.
    tree, 
    /// The offset between the fragment's tree and the document that
    /// this fragment can be used against. Add this when going from
    /// document to tree positions, subtract it to go from tree to
    /// document positions.
    offset, openStart = false, openEnd = false) {
        this.from = from;
        this.to = to;
        this.tree = tree;
        this.offset = offset;
        this.open = (openStart ? 1 /* Start */ : 0) | (openEnd ? 2 /* End */ : 0);
    }
    /// Whether the start of the fragment represents the start of a
    /// parse, or the end of a change. (In the second case, it may not
    /// be safe to reuse some nodes at the start, depending on the
    /// parsing algorithm.)
    get openStart() { return (this.open & 1 /* Start */) > 0; }
    /// Whether the end of the fragment represents the end of a
    /// full-document parse, or the start of a change.
    get openEnd() { return (this.open & 2 /* End */) > 0; }
    /// Create a set of fragments from a freshly parsed tree, or update
    /// an existing set of fragments by replacing the ones that overlap
    /// with a tree with content from the new tree. When `partial` is
    /// true, the parse is treated as incomplete, and the resulting
    /// fragment has [`openEnd`](#common.TreeFragment.openEnd) set to
    /// true.
    static addTree(tree, fragments = [], partial = false) {
        let result = [new TreeFragment(0, tree.length, tree, 0, false, partial)];
        for (let f of fragments)
            if (f.to > tree.length)
                result.push(f);
        return result;
    }
    /// Apply a set of edits to an array of fragments, removing or
    /// splitting fragments as necessary to remove edited ranges, and
    /// adjusting offsets for fragments that moved.
    static applyChanges(fragments, changes, minGap = 128) {
        if (!changes.length)
            return fragments;
        let result = [];
        let fI = 1, nextF = fragments.length ? fragments[0] : null;
        for (let cI = 0, pos = 0, off = 0;; cI++) {
            let nextC = cI < changes.length ? changes[cI] : null;
            let nextPos = nextC ? nextC.fromA : 1e9;
            if (nextPos - pos >= minGap)
                while (nextF && nextF.from < nextPos) {
                    let cut = nextF;
                    if (pos >= cut.from || nextPos <= cut.to || off) {
                        let fFrom = Math.max(cut.from, pos) - off, fTo = Math.min(cut.to, nextPos) - off;
                        cut = fFrom >= fTo ? null : new TreeFragment(fFrom, fTo, cut.tree, cut.offset + off, cI > 0, !!nextC);
                    }
                    if (cut)
                        result.push(cut);
                    if (nextF.to > nextPos)
                        break;
                    nextF = fI < fragments.length ? fragments[fI++] : null;
                }
            if (!nextC)
                break;
            pos = nextC.toA;
            off = nextC.toA - nextC.toB;
        }
        return result;
    }
}
/// A superclass that parsers should extend.
class Parser {
    /// Start a parse, returning a [partial parse](#common.PartialParse)
    /// object. [`fragments`](#common.TreeFragment) can be passed in to
    /// make the parse incremental.
    ///
    /// By default, the entire input is parsed. You can pass `ranges`,
    /// which should be a sorted array of non-empty, non-overlapping
    /// ranges, to parse only those ranges. The tree returned in that
    /// case will start at `ranges[0].from`.
    startParse(input, fragments, ranges) {
        if (typeof input == "string")
            input = new StringInput(input);
        ranges = !ranges ? [new Range(0, input.length)] : ranges.length ? ranges.map(r => new Range(r.from, r.to)) : [new Range(0, 0)];
        return this.createParse(input, fragments || [], ranges);
    }
    /// Run a full parse, returning the resulting tree.
    parse(input, fragments, ranges) {
        let parse = this.startParse(input, fragments, ranges);
        for (;;) {
            let done = parse.advance();
            if (done)
                return done;
        }
    }
}
class StringInput {
    constructor(string) {
        this.string = string;
    }
    get length() { return this.string.length; }
    chunk(from) { return this.string.slice(from); }
    get lineChunks() { return false; }
    read(from, to) { return this.string.slice(from, to); }
}

/// Create a parse wrapper that, after the inner parse completes,
/// scans its tree for mixed language regions with the `nest`
/// function, runs the resulting [inner parses](#common.NestedParse),
/// and then [mounts](#common.NodeProp^mounted) their results onto the
/// tree.
function parseMixed(nest) {
    return (parse, input, fragments, ranges) => new MixedParse(parse, nest, input, fragments, ranges);
}
class InnerParse {
    constructor(parser, parse, overlay, target, ranges) {
        this.parser = parser;
        this.parse = parse;
        this.overlay = overlay;
        this.target = target;
        this.ranges = ranges;
    }
}
class ActiveOverlay {
    constructor(parser, predicate, mounts, index, start, target, prev) {
        this.parser = parser;
        this.predicate = predicate;
        this.mounts = mounts;
        this.index = index;
        this.start = start;
        this.target = target;
        this.prev = prev;
        this.depth = 0;
        this.ranges = [];
    }
}
const stoppedInner = new NodeProp({ perNode: true });
class MixedParse {
    constructor(base, nest, input, fragments, ranges) {
        this.nest = nest;
        this.input = input;
        this.fragments = fragments;
        this.ranges = ranges;
        this.inner = [];
        this.innerDone = 0;
        this.baseTree = null;
        this.stoppedAt = null;
        this.baseParse = base;
    }
    advance() {
        if (this.baseParse) {
            let done = this.baseParse.advance();
            if (!done)
                return null;
            this.baseParse = null;
            this.baseTree = done;
            this.startInner();
            if (this.stoppedAt != null)
                for (let inner of this.inner)
                    inner.parse.stopAt(this.stoppedAt);
        }
        if (this.innerDone == this.inner.length) {
            let result = this.baseTree;
            if (this.stoppedAt != null)
                result = new Tree(result.type, result.children, result.positions, result.length, result.propValues.concat([[stoppedInner, this.stoppedAt]]));
            return result;
        }
        let inner = this.inner[this.innerDone], done = inner.parse.advance();
        if (done) {
            this.innerDone++;
            // This is a somewhat dodgy but super helpful hack where we
            // patch up nodes created by the inner parse (and thus
            // presumably not aliased anywhere else) to hold the information
            // about the inner parse.
            let props = Object.assign(Object.create(null), inner.target.props);
            props[NodeProp.mounted.id] = new MountedTree(done, inner.overlay, inner.parser);
            inner.target.props = props;
        }
        return null;
    }
    get parsedPos() {
        if (this.baseParse)
            return 0;
        let pos = this.input.length;
        for (let i = this.innerDone; i < this.inner.length; i++) {
            if (this.inner[i].ranges[0].from < pos)
                pos = Math.min(pos, this.inner[i].parse.parsedPos);
        }
        return pos;
    }
    stopAt(pos) {
        this.stoppedAt = pos;
        if (this.baseParse)
            this.baseParse.stopAt(pos);
        else
            for (let i = this.innerDone; i < this.inner.length; i++)
                this.inner[i].parse.stopAt(pos);
    }
    startInner() {
        let fragmentCursor = new FragmentCursor(this.fragments);
        let overlay = null;
        let covered = null;
        let cursor = new TreeCursor(new TreeNode(this.baseTree, this.ranges[0].from, 0, null), IterMode.IncludeAnonymous | IterMode.IgnoreMounts);
        scan: for (let nest, isCovered; this.stoppedAt == null || cursor.from < this.stoppedAt;) {
            let enter = true, range;
            if (fragmentCursor.hasNode(cursor)) {
                if (overlay) {
                    let match = overlay.mounts.find(m => m.frag.from <= cursor.from && m.frag.to >= cursor.to && m.mount.overlay);
                    if (match)
                        for (let r of match.mount.overlay) {
                            let from = r.from + match.pos, to = r.to + match.pos;
                            if (from >= cursor.from && to <= cursor.to && !overlay.ranges.some(r => r.from < to && r.to > from))
                                overlay.ranges.push({ from, to });
                        }
                }
                enter = false;
            }
            else if (covered && (isCovered = checkCover(covered.ranges, cursor.from, cursor.to))) {
                enter = isCovered != 2 /* Full */;
            }
            else if (!cursor.type.isAnonymous && cursor.from < cursor.to && (nest = this.nest(cursor, this.input))) {
                if (!cursor.tree)
                    materialize(cursor);
                let oldMounts = fragmentCursor.findMounts(cursor.from, nest.parser);
                if (typeof nest.overlay == "function") {
                    overlay = new ActiveOverlay(nest.parser, nest.overlay, oldMounts, this.inner.length, cursor.from, cursor.tree, overlay);
                }
                else {
                    let ranges = punchRanges(this.ranges, nest.overlay || [new Range(cursor.from, cursor.to)]);
                    if (ranges.length)
                        this.inner.push(new InnerParse(nest.parser, nest.parser.startParse(this.input, enterFragments(oldMounts, ranges), ranges), nest.overlay ? nest.overlay.map(r => new Range(r.from - cursor.from, r.to - cursor.from)) : null, cursor.tree, ranges));
                    if (!nest.overlay)
                        enter = false;
                    else if (ranges.length)
                        covered = { ranges, depth: 0, prev: covered };
                }
            }
            else if (overlay && (range = overlay.predicate(cursor))) {
                if (range === true)
                    range = new Range(cursor.from, cursor.to);
                if (range.from < range.to)
                    overlay.ranges.push(range);
            }
            if (enter && cursor.firstChild()) {
                if (overlay)
                    overlay.depth++;
                if (covered)
                    covered.depth++;
            }
            else {
                for (;;) {
                    if (cursor.nextSibling())
                        break;
                    if (!cursor.parent())
                        break scan;
                    if (overlay && !--overlay.depth) {
                        let ranges = punchRanges(this.ranges, overlay.ranges);
                        if (ranges.length)
                            this.inner.splice(overlay.index, 0, new InnerParse(overlay.parser, overlay.parser.startParse(this.input, enterFragments(overlay.mounts, ranges), ranges), overlay.ranges.map(r => new Range(r.from - overlay.start, r.to - overlay.start)), overlay.target, ranges));
                        overlay = overlay.prev;
                    }
                    if (covered && !--covered.depth)
                        covered = covered.prev;
                }
            }
        }
    }
}
function checkCover(covered, from, to) {
    for (let range of covered) {
        if (range.from >= to)
            break;
        if (range.to > from)
            return range.from <= from && range.to >= to ? 2 /* Full */ : 1 /* Partial */;
    }
    return 0 /* None */;
}
// Take a piece of buffer and convert it into a stand-alone
// TreeBuffer.
function sliceBuf(buf, startI, endI, nodes, positions, off) {
    if (startI < endI) {
        let from = buf.buffer[startI + 1], to = buf.buffer[endI - 2];
        nodes.push(buf.slice(startI, endI, from, to));
        positions.push(from - off);
    }
}
// This function takes a node that's in a buffer, and converts it, and
// its parent buffer nodes, into a Tree. This is again acting on the
// assumption that the trees and buffers have been constructed by the
// parse that was ran via the mix parser, and thus aren't shared with
// any other code, making violations of the immutability safe.
function materialize(cursor) {
    let { node } = cursor, depth = 0;
    // Scan up to the nearest tree
    do {
        cursor.parent();
        depth++;
    } while (!cursor.tree);
    // Find the index of the buffer in that tree
    let i = 0, base = cursor.tree, off = 0;
    for (;; i++) {
        off = base.positions[i] + cursor.from;
        if (off <= node.from && off + base.children[i].length >= node.to)
            break;
    }
    let buf = base.children[i], b = buf.buffer;
    // Split a level in the buffer, putting the nodes before and after
    // the child that contains `node` into new buffers.
    function split(startI, endI, type, innerOffset, length) {
        let i = startI;
        while (b[i + 2] + off <= node.from)
            i = b[i + 3];
        let children = [], positions = [];
        sliceBuf(buf, startI, i, children, positions, innerOffset);
        let from = b[i + 1], to = b[i + 2];
        let isTarget = from + off == node.from && to + off == node.to && b[i] == node.type.id;
        children.push(isTarget ? node.toTree() : split(i + 4, b[i + 3], buf.set.types[b[i]], from, to - from));
        positions.push(from - innerOffset);
        sliceBuf(buf, b[i + 3], endI, children, positions, innerOffset);
        return new Tree(type, children, positions, length);
    }
    base.children[i] = split(0, b.length, NodeType.none, 0, buf.length);
    // Move the cursor back to the target node
    for (let d = 0; d <= depth; d++)
        cursor.childAfter(node.from);
}
class StructureCursor {
    constructor(root, offset) {
        this.offset = offset;
        this.done = false;
        this.cursor = root.cursor(IterMode.IncludeAnonymous | IterMode.IgnoreMounts);
    }
    // Move to the first node (in pre-order) that starts at or after `pos`.
    moveTo(pos) {
        let { cursor } = this, p = pos - this.offset;
        while (!this.done && cursor.from < p) {
            if (cursor.to >= pos && cursor.enter(p, 1, IterMode.IgnoreOverlays | IterMode.ExcludeBuffers)) ;
            else if (!cursor.next(false))
                this.done = true;
        }
    }
    hasNode(cursor) {
        this.moveTo(cursor.from);
        if (!this.done && this.cursor.from + this.offset == cursor.from && this.cursor.tree) {
            for (let tree = this.cursor.tree;;) {
                if (tree == cursor.tree)
                    return true;
                if (tree.children.length && tree.positions[0] == 0 && tree.children[0] instanceof Tree)
                    tree = tree.children[0];
                else
                    break;
            }
        }
        return false;
    }
}
class FragmentCursor {
    constructor(fragments) {
        var _a;
        this.fragments = fragments;
        this.curTo = 0;
        this.fragI = 0;
        if (fragments.length) {
            let first = this.curFrag = fragments[0];
            this.curTo = (_a = first.tree.prop(stoppedInner)) !== null && _a !== void 0 ? _a : first.to;
            this.inner = new StructureCursor(first.tree, -first.offset);
        }
        else {
            this.curFrag = this.inner = null;
        }
    }
    hasNode(node) {
        while (this.curFrag && node.from >= this.curTo)
            this.nextFrag();
        return this.curFrag && this.curFrag.from <= node.from && this.curTo >= node.to && this.inner.hasNode(node);
    }
    nextFrag() {
        var _a;
        this.fragI++;
        if (this.fragI == this.fragments.length) {
            this.curFrag = this.inner = null;
        }
        else {
            let frag = this.curFrag = this.fragments[this.fragI];
            this.curTo = (_a = frag.tree.prop(stoppedInner)) !== null && _a !== void 0 ? _a : frag.to;
            this.inner = new StructureCursor(frag.tree, -frag.offset);
        }
    }
    findMounts(pos, parser) {
        var _a;
        let result = [];
        if (this.inner) {
            this.inner.cursor.moveTo(pos, 1);
            for (let pos = this.inner.cursor.node; pos; pos = pos.parent) {
                let mount = (_a = pos.tree) === null || _a === void 0 ? void 0 : _a.prop(NodeProp.mounted);
                if (mount && mount.parser == parser) {
                    for (let i = this.fragI; i < this.fragments.length; i++) {
                        let frag = this.fragments[i];
                        if (frag.from >= pos.to)
                            break;
                        if (frag.tree == this.curFrag.tree)
                            result.push({
                                frag,
                                pos: pos.from - frag.offset,
                                mount
                            });
                    }
                }
            }
        }
        return result;
    }
}
function punchRanges(outer, ranges) {
    let copy = null, current = ranges;
    for (let i = 1, j = 0; i < outer.length; i++) {
        let gapFrom = outer[i - 1].to, gapTo = outer[i].from;
        for (; j < current.length; j++) {
            let r = current[j];
            if (r.from >= gapTo)
                break;
            if (r.to <= gapFrom)
                continue;
            if (!copy)
                current = copy = ranges.slice();
            if (r.from < gapFrom) {
                copy[j] = new Range(r.from, gapFrom);
                if (r.to > gapTo)
                    copy.splice(j + 1, 0, new Range(gapTo, r.to));
            }
            else if (r.to > gapTo) {
                copy[j--] = new Range(gapTo, r.to);
            }
            else {
                copy.splice(j--, 1);
            }
        }
    }
    return current;
}
function findCoverChanges(a, b, from, to) {
    let iA = 0, iB = 0, inA = false, inB = false, pos = -1e9;
    let result = [];
    for (;;) {
        let nextA = iA == a.length ? 1e9 : inA ? a[iA].to : a[iA].from;
        let nextB = iB == b.length ? 1e9 : inB ? b[iB].to : b[iB].from;
        if (inA != inB) {
            let start = Math.max(pos, from), end = Math.min(nextA, nextB, to);
            if (start < end)
                result.push(new Range(start, end));
        }
        pos = Math.min(nextA, nextB);
        if (pos == 1e9)
            break;
        if (nextA == pos) {
            if (!inA)
                inA = true;
            else {
                inA = false;
                iA++;
            }
        }
        if (nextB == pos) {
            if (!inB)
                inB = true;
            else {
                inB = false;
                iB++;
            }
        }
    }
    return result;
}
// Given a number of fragments for the outer tree, and a set of ranges
// to parse, find fragments for inner trees mounted around those
// ranges, if any.
function enterFragments(mounts, ranges) {
    let result = [];
    for (let { pos, mount, frag } of mounts) {
        let startPos = pos + (mount.overlay ? mount.overlay[0].from : 0), endPos = startPos + mount.tree.length;
        let from = Math.max(frag.from, startPos), to = Math.min(frag.to, endPos);
        if (mount.overlay) {
            let overlay = mount.overlay.map(r => new Range(r.from + pos, r.to + pos));
            let changes = findCoverChanges(ranges, overlay, from, to);
            for (let i = 0, pos = from;; i++) {
                let last = i == changes.length, end = last ? to : changes[i].from;
                if (end > pos)
                    result.push(new TreeFragment(pos, end, mount.tree, -startPos, frag.from >= pos, frag.to <= end));
                if (last)
                    break;
                pos = changes[i].to;
            }
        }
        else {
            result.push(new TreeFragment(from, to, mount.tree, -startPos, frag.from >= startPos, frag.to <= endPos));
        }
    }
    return result;
}

export { DefaultBufferLength, IterMode, MountedTree, NodeProp, NodeSet, NodeType, NodeWeakMap, Parser, Tree, TreeBuffer, TreeCursor, TreeFragment, parseMixed };