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/**
* @fileoverview Define the cursor which iterates tokens and comments in reverse.
* @author Toru Nagashima
*/
"use strict";
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const Cursor = require("./cursor");
const utils = require("./utils");
//------------------------------------------------------------------------------
// Exports
//------------------------------------------------------------------------------
/**
* The cursor which iterates tokens and comments in reverse.
*/
module.exports = class BackwardTokenCommentCursor extends Cursor {
/**
* Initializes this cursor.
* @param {Token[]} tokens The array of tokens.
* @param {Comment[]} comments The array of comments.
* @param {Object} indexMap The map from locations to indices in `tokens`.
* @param {number} startLoc The start location of the iteration range.
* @param {number} endLoc The end location of the iteration range.
*/
constructor(tokens, comments, indexMap, startLoc, endLoc) {
super();
this.tokens = tokens;
this.comments = comments;
this.tokenIndex = utils.getLastIndex(tokens, indexMap, endLoc);
this.commentIndex = utils.search(comments, endLoc) - 1;
this.border = startLoc;
}
/** @inheritdoc */
moveNext() {
const token = (this.tokenIndex >= 0) ? this.tokens[this.tokenIndex] : null;
const comment = (this.commentIndex >= 0) ? this.comments[this.commentIndex] : null;
if (token && (!comment || token.range[1] > comment.range[1])) {
this.current = token;
this.tokenIndex -= 1;
} else if (comment) {
this.current = comment;
this.commentIndex -= 1;
} else {
this.current = null;
}
return Boolean(this.current) && (this.border === -1 || this.current.range[0] >= this.border);
}
};
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