58 lines
2.0 KiB
JavaScript
58 lines
2.0 KiB
JavaScript
/**
|
|
* @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);
|
|
}
|
|
};
|