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Diffstat (limited to 'src/data/composite/data/withUniqueItemsOnly.js')
-rw-r--r-- | src/data/composite/data/withUniqueItemsOnly.js | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/src/data/composite/data/withUniqueItemsOnly.js b/src/data/composite/data/withUniqueItemsOnly.js new file mode 100644 index 0000000..7ee08b0 --- /dev/null +++ b/src/data/composite/data/withUniqueItemsOnly.js @@ -0,0 +1,40 @@ +// Excludes duplicate items from a list and provides the results, overwriting +// the list in-place, if possible. + +import {input, templateCompositeFrom} from '#composite'; +import {unique} from '#sugar'; + +export default templateCompositeFrom({ + annotation: `withUniqueItemsOnly`, + + inputs: { + list: input({type: 'array'}), + }, + + outputs: ({ + [input.staticDependency('list')]: list, + }) => [list ?? '#uniqueItems'], + + steps: () => [ + { + dependencies: [input('list')], + compute: (continuation, { + [input('list')]: list, + }) => continuation({ + ['#values']: + unique(list), + }), + }, + + { + dependencies: ['#values', input.staticDependency('list')], + compute: (continuation, { + '#values': values, + [input.staticDependency('list')]: list, + }) => continuation({ + [list ?? '#uniqueItems']: + values, + }), + }, + ], +}); |