1 | /**
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2 | * @fileoverview Define utility functions for token store.
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3 | * @author Toru Nagashima
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4 | */
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5 | ;
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6 |
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7 | //------------------------------------------------------------------------------
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8 | // Helpers
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9 | //------------------------------------------------------------------------------
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10 |
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11 | /**
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12 | * Gets `token.range[0]` from the given token.
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13 | * @param {Node|Token|Comment} token The token to get.
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14 | * @returns {number} The start location.
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15 | * @private
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16 | */
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17 | function getStartLocation(token) {
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18 | return token.range[0];
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19 | }
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20 |
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21 | //------------------------------------------------------------------------------
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22 | // Exports
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23 | //------------------------------------------------------------------------------
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24 |
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25 | /**
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26 | * Finds the index of the first token which is after the given location.
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27 | * If it was not found, this returns `tokens.length`.
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28 | * @param {(Token|Comment)[]} tokens It searches the token in this list.
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29 | * @param {number} location The location to search.
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30 | * @returns {number} The found index or `tokens.length`.
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31 | */
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32 | exports.search = function search(tokens, location) {
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33 | const index = tokens.findIndex(el => location <= getStartLocation(el));
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34 |
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35 | return index === -1 ? tokens.length : index;
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36 | };
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37 |
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38 | /**
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39 | * Gets the index of the `startLoc` in `tokens`.
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40 | * `startLoc` can be the value of `node.range[1]`, so this checks about `startLoc - 1` as well.
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41 | * @param {(Token|Comment)[]} tokens The tokens to find an index.
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42 | * @param {Object} indexMap The map from locations to indices.
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43 | * @param {number} startLoc The location to get an index.
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44 | * @returns {number} The index.
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45 | */
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46 | exports.getFirstIndex = function getFirstIndex(tokens, indexMap, startLoc) {
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47 | if (startLoc in indexMap) {
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48 | return indexMap[startLoc];
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49 | }
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50 | if ((startLoc - 1) in indexMap) {
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51 | const index = indexMap[startLoc - 1];
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52 | const token = (index >= 0 && index < tokens.length) ? tokens[index] : null;
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53 |
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54 | /*
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55 | * For the map of "comment's location -> token's index", it points the next token of a comment.
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56 | * In that case, +1 is unnecessary.
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57 | */
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58 | if (token && token.range[0] >= startLoc) {
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59 | return index;
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60 | }
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61 | return index + 1;
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62 | }
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63 | return 0;
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64 | };
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65 |
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66 | /**
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67 | * Gets the index of the `endLoc` in `tokens`.
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68 | * The information of end locations are recorded at `endLoc - 1` in `indexMap`, so this checks about `endLoc - 1` as well.
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69 | * @param {(Token|Comment)[]} tokens The tokens to find an index.
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70 | * @param {Object} indexMap The map from locations to indices.
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71 | * @param {number} endLoc The location to get an index.
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72 | * @returns {number} The index.
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73 | */
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74 | exports.getLastIndex = function getLastIndex(tokens, indexMap, endLoc) {
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75 | if (endLoc in indexMap) {
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76 | return indexMap[endLoc] - 1;
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77 | }
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78 | if ((endLoc - 1) in indexMap) {
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79 | const index = indexMap[endLoc - 1];
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80 | const token = (index >= 0 && index < tokens.length) ? tokens[index] : null;
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81 |
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82 | /*
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83 | * For the map of "comment's location -> token's index", it points the next token of a comment.
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84 | * In that case, -1 is necessary.
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85 | */
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86 | if (token && token.range[1] > endLoc) {
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87 | return index - 1;
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88 | }
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89 | return index;
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90 | }
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91 | return tokens.length - 1;
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92 | };
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