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Diffstat (limited to 'node_modules/webpack/lib/util/SetHelpers.js')
-rw-r--r-- | node_modules/webpack/lib/util/SetHelpers.js | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/node_modules/webpack/lib/util/SetHelpers.js b/node_modules/webpack/lib/util/SetHelpers.js new file mode 100644 index 0000000..96c063c --- /dev/null +++ b/node_modules/webpack/lib/util/SetHelpers.js @@ -0,0 +1,48 @@ +"use strict"; + +/** + * intersect creates Set containing the intersection of elements between all sets + * @param {Set[]} sets an array of sets being checked for shared elements + * @returns {Set<TODO>} returns a new Set containing the intersecting items + */ +const intersect = sets => { + if (sets.length === 0) return new Set(); + if (sets.length === 1) return new Set(sets[0]); + let minSize = Infinity; + let minIndex = -1; + for (let i = 0; i < sets.length; i++) { + const size = sets[i].size; + if (size < minSize) { + minIndex = i; + minSize = size; + } + } + const current = new Set(sets[minIndex]); + for (let i = 0; i < sets.length; i++) { + if (i === minIndex) continue; + const set = sets[i]; + for (const item of current) { + if (!set.has(item)) { + current.delete(item); + } + } + } + return current; +}; + +/** + * Checks if a set is the subset of another set + * @param {Set<TODO>} bigSet a Set which contains the original elements to compare against + * @param {Set<TODO>} smallSet the set whos elements might be contained inside of bigSet + * @returns {boolean} returns true if smallSet contains all elements inside of the bigSet + */ +const isSubset = (bigSet, smallSet) => { + if (bigSet.size < smallSet.size) return false; + for (const item of smallSet) { + if (!bigSet.has(item)) return false; + } + return true; +}; + +exports.intersect = intersect; +exports.isSubset = isSubset; |