91 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			91 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| /**
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|  * @fileoverview Define 2 token factories; forward and backward.
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|  * @author Toru Nagashima
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|  */
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| "use strict";
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| 
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| //------------------------------------------------------------------------------
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| // Requirements
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| //------------------------------------------------------------------------------
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| 
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| const BackwardTokenCommentCursor = require("./backward-token-comment-cursor");
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| const BackwardTokenCursor = require("./backward-token-cursor");
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| const FilterCursor = require("./filter-cursor");
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| const ForwardTokenCommentCursor = require("./forward-token-comment-cursor");
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| const ForwardTokenCursor = require("./forward-token-cursor");
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| const LimitCursor = require("./limit-cursor");
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| const SkipCursor = require("./skip-cursor");
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| 
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| //------------------------------------------------------------------------------
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| // Helpers
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| //------------------------------------------------------------------------------
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| 
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| /**
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|  * The cursor factory.
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|  * @private
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|  */
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| class CursorFactory {
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| 
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|     /**
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|      * Initializes this cursor.
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|      * @param {Function} TokenCursor The class of the cursor which iterates tokens only.
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|      * @param {Function} TokenCommentCursor The class of the cursor which iterates the mix of tokens and comments.
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|      */
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|     constructor(TokenCursor, TokenCommentCursor) {
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|         this.TokenCursor = TokenCursor;
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|         this.TokenCommentCursor = TokenCommentCursor;
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|     }
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| 
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|     /**
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|      * Creates a base cursor instance that can be decorated by createCursor.
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|      * @param {Token[]} tokens The array of tokens.
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|      * @param {Comment[]} comments The array of comments.
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|      * @param {Object} indexMap The map from locations to indices in `tokens`.
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|      * @param {number} startLoc The start location of the iteration range.
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|      * @param {number} endLoc The end location of the iteration range.
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|      * @param {boolean} includeComments The flag to iterate comments as well.
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|      * @returns {Cursor} The created base cursor.
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|      */
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|     createBaseCursor(tokens, comments, indexMap, startLoc, endLoc, includeComments) {
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|         const Cursor = includeComments ? this.TokenCommentCursor : this.TokenCursor;
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| 
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|         return new Cursor(tokens, comments, indexMap, startLoc, endLoc);
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|     }
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| 
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|     /**
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|      * Creates a cursor that iterates tokens with normalized options.
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|      * @param {Token[]} tokens The array of tokens.
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|      * @param {Comment[]} comments The array of comments.
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|      * @param {Object} indexMap The map from locations to indices in `tokens`.
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|      * @param {number} startLoc The start location of the iteration range.
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|      * @param {number} endLoc The end location of the iteration range.
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|      * @param {boolean} includeComments The flag to iterate comments as well.
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|      * @param {Function|null} filter The predicate function to choose tokens.
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|      * @param {number} skip The count of tokens the cursor skips.
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|      * @param {number} count The maximum count of tokens the cursor iterates. Zero is no iteration for backward compatibility.
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|      * @returns {Cursor} The created cursor.
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|      */
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|     createCursor(tokens, comments, indexMap, startLoc, endLoc, includeComments, filter, skip, count) {
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|         let cursor = this.createBaseCursor(tokens, comments, indexMap, startLoc, endLoc, includeComments);
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| 
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|         if (filter) {
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|             cursor = new FilterCursor(cursor, filter);
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|         }
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|         if (skip >= 1) {
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|             cursor = new SkipCursor(cursor, skip);
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|         }
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|         if (count >= 0) {
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|             cursor = new LimitCursor(cursor, count);
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|         }
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| 
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|         return cursor;
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|     }
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| }
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| 
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| //------------------------------------------------------------------------------
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| // Exports
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| //------------------------------------------------------------------------------
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| 
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| exports.forward = new CursorFactory(ForwardTokenCursor, ForwardTokenCommentCursor);
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| exports.backward = new CursorFactory(BackwardTokenCursor, BackwardTokenCommentCursor);
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