Fixes #1660: Add running total function for collection #26 (#1792)

core/src/main/java/apoc/coll/Coll.java

 package apoc.coll;
 
 import apoc.result.ListResult;
+import com.google.common.util.concurrent.AtomicDouble;
 import org.apache.commons.lang3.mutable.MutableInt;
 import org.apache.commons.math3.util.Combinations;
 import org.neo4j.graphdb.GraphDatabaseService;
@@ -50,6 +51,18 @@ public class Coll {
 
     @Context public Transaction tx;
 
+    @UserFunction
+    @Description("apoc.coll.runningTotal(list1) - returns an accumulative array. For example apoc.coll.runningTotal([1,2,3.5]) return [1,3,6.5]")
+    public List<Number> runningTotal(@Name("list") List<Number> list) {
+        if (list == null || list.isEmpty()) return null;
+        AtomicDouble sum = new AtomicDouble();
+        return list.stream().map(i -> {
+                    double value = sum.addAndGet(i.doubleValue());
+                    if (value == sum.longValue()) return sum.longValue();
+                    return value;
+                }).collect(Collectors.toList());
+    }
+
     @Procedure
     @Description("apoc.coll.zipToRows(list1,list2) - creates pairs like zip but emits one row per pair")
     public Stream<ListResult> zipToRows(@Name("list1") List<Object> list1, @Name("list2") List<Object> list2) {

core/src/test/java/apoc/coll/CollTest.java

@@ -30,6 +30,12 @@ public class CollTest {
         TestUtil.registerProcedure(db, Coll.class, Json.class);
     }
 
+    @Test
+    public void testRunningTotal() throws Exception {
+        testCall(db, "RETURN apoc.coll.runningTotal([1,2,3,4,5.5,1]) as value",
+                (row) -> assertEquals(asList(1L, 3L, 6L, 10L, 15.5D, 16.5D), row.get("value")));
+    }
+
     @Test
     public void testZip() throws Exception {
         testCall(db, "RETURN apoc.coll.zip([1,2,3],[4,5]) as value",

docs/asciidoc/modules/ROOT/examples/generated-documentation/apoc.coll-lite.csv

@@ -37,6 +37,7 @@
 ¦apoc.coll.remove(coll :: LIST? OF ANY?, index :: INTEGER?, length = 1 :: INTEGER?) :: (LIST? OF ANY?)
 ¦apoc.coll.removeAll(first :: LIST? OF ANY?, second :: LIST? OF ANY?) :: (LIST? OF ANY?)
 ¦apoc.coll.reverse(coll :: LIST? OF ANY?) :: (LIST? OF ANY?)
+¦apoc.coll.runningTotal(list :: LIST? OF NUMBER?) :: (LIST? OF ANY?)
 ¦apoc.coll.set(coll :: LIST? OF ANY?, index :: INTEGER?, value :: ANY?) :: (LIST? OF ANY?)
 ¦apoc.coll.shuffle(coll :: LIST? OF ANY?) :: (LIST? OF ANY?)
 ¦apoc.coll.sort(coll :: LIST? OF ANY?) :: (LIST? OF ANY?)

docs/asciidoc/modules/ROOT/examples/generated-documentation/apoc.coll.csv

@@ -37,6 +37,7 @@
 ¦function¦apoc.coll.remove¦apoc.coll.remove(coll :: LIST? OF ANY?, index :: INTEGER?, length = 1 :: INTEGER?) :: (LIST? OF ANY?)¦apoc.coll.remove(coll, index, [length=1]) | remove range of values from index to length
 ¦function¦apoc.coll.removeAll¦apoc.coll.removeAll(first :: LIST? OF ANY?, second :: LIST? OF ANY?) :: (LIST? OF ANY?)¦apoc.coll.removeAll(first, second) - returns first list with all elements of second list removed
 ¦function¦apoc.coll.reverse¦apoc.coll.reverse(coll :: LIST? OF ANY?) :: (LIST? OF ANY?)¦apoc.coll.reverse(coll) - returns reversed list
+¦function¦apoc.coll.runningTotal¦apoc.coll.runningTotal(list :: LIST? OF NUMBER?) :: (LIST? OF ANY?)¦apoc.coll.runningTotal(list1) - returns an accumulative array. For example apoc.coll.runningTotal([1,2,3.5]) return [1,3,6.5]
 ¦function¦apoc.coll.set¦apoc.coll.set(coll :: LIST? OF ANY?, index :: INTEGER?, value :: ANY?) :: (LIST? OF ANY?)¦apoc.coll.set(coll, index, value) | set index to value
 ¦function¦apoc.coll.shuffle¦apoc.coll.shuffle(coll :: LIST? OF ANY?) :: (LIST? OF ANY?)¦apoc.coll.shuffle(coll) - returns the shuffled list
 ¦function¦apoc.coll.sort¦apoc.coll.sort(coll :: LIST? OF ANY?) :: (LIST? OF ANY?)¦apoc.coll.sort(coll) sort on Collections

docs/asciidoc/modules/ROOT/examples/generated-documentation/apoc.coll.runningTotal-lite.csv

+¦signature
+¦apoc.coll.runningTotal(list :: LIST? OF NUMBER?) :: (LIST? OF ANY?)

docs/asciidoc/modules/ROOT/examples/generated-documentation/apoc.coll.runningTotal.csv

+¦type¦qualified name¦signature¦description
+¦function¦apoc.coll.runningTotal¦apoc.coll.runningTotal(list :: LIST? OF NUMBER?) :: (LIST? OF ANY?)¦apoc.coll.runningTotal(list1) - returns an accumulative array. For example apoc.coll.runningTotal([1,2,3.5]) return [1,3,6.5]

docs/asciidoc/modules/ROOT/examples/generated-documentation/documentation.csv

@@ -334,6 +334,7 @@ for the provided `label` and `uuidProperty`, in case the UUID handler is already
 ¦function¦apoc.coll.remove¦apoc.coll.remove(coll :: LIST? OF ANY?, index :: INTEGER?, length = 1 :: INTEGER?) :: (LIST? OF ANY?)¦apoc.coll.remove(coll, index, [length=1]) | remove range of values from index to length¦true¦
 ¦function¦apoc.coll.removeAll¦apoc.coll.removeAll(first :: LIST? OF ANY?, second :: LIST? OF ANY?) :: (LIST? OF ANY?)¦apoc.coll.removeAll(first, second) - returns first list with all elements of second list removed¦true¦
 ¦function¦apoc.coll.reverse¦apoc.coll.reverse(coll :: LIST? OF ANY?) :: (LIST? OF ANY?)¦apoc.coll.reverse(coll) - returns reversed list¦true¦
+¦function¦apoc.coll.runningTotal¦apoc.coll.runningTotal(list :: LIST? OF NUMBER?) :: (LIST? OF ANY?)¦apoc.coll.runningTotal(list1) - returns an accumulative array. For example apoc.coll.runningTotal([1,2,3.5]) return [1,3,6.5]¦true¦
 ¦function¦apoc.coll.set¦apoc.coll.set(coll :: LIST? OF ANY?, index :: INTEGER?, value :: ANY?) :: (LIST? OF ANY?)¦apoc.coll.set(coll, index, value) | set index to value¦true¦
 ¦function¦apoc.coll.shuffle¦apoc.coll.shuffle(coll :: LIST? OF ANY?) :: (LIST? OF ANY?)¦apoc.coll.shuffle(coll) - returns the shuffled list¦true¦
 ¦function¦apoc.coll.sort¦apoc.coll.sort(coll :: LIST? OF ANY?) :: (LIST? OF ANY?)¦apoc.coll.sort(coll) sort on Collections¦true¦

docs/asciidoc/modules/ROOT/pages/overview/apoc.coll/apoc.coll.runningTotal.adoc

+////
+This file is generated by DocsTest, so don't change it!
+////
+
+= apoc.coll.runningTotal
+:description: This section contains reference documentation for the apoc.coll.runningTotal function.
+
+label:function[] label:apoc-core[]
+
+[.emphasis]
+apoc.coll.runningTotal(list1) - returns an accumulative array. For example apoc.coll.runningTotal([1,2,3.5]) return [1,3,6.5]
+
+== Signature
+
+[source]
+----
+apoc.coll.runningTotal(list :: LIST? OF NUMBER?) :: (LIST? OF ANY?)
+----
+
+== Input parameters
+[.procedures, opts=header]
+|===
+| Name | Type | Default 
+|list|LIST? OF NUMBER?|null
+|===
+

docs/asciidoc/modules/ROOT/pages/overview/apoc.coll/index.adoc

@@ -198,6 +198,11 @@ apoc.coll.removeAll(first, second) - returns first list with all elements of sec
 apoc.coll.reverse(coll) - returns reversed list
 |label:function[]
 |label:apoc-core[]
+|xref::overview/apoc.coll/apoc.coll.runningTotal.adoc[apoc.coll.runningTotal icon:book[]]
+
+apoc.coll.runningTotal(list1) - returns an accumulative array. For example apoc.coll.runningTotal([1,2,3.5]) return [1,3,6.5]
+|label:function[]
+|label:apoc-core[]
 |xref::overview/apoc.coll/apoc.coll.set.adoc[apoc.coll.set icon:book[]]
 
 apoc.coll.set(coll, index, value) \| set index to value

docs/asciidoc/modules/ROOT/partials/generated-documentation/documentation.adoc

@@ -422,6 +422,11 @@ apoc.coll.removeAll(first, second) - returns first list with all elements of sec
 apoc.coll.reverse(coll) - returns reversed list
 |label:function[]
 |label:apoc-core[]
+|xref::overview/apoc.coll/apoc.coll.runningTotal.adoc[apoc.coll.runningTotal icon:book[]]
+
+apoc.coll.runningTotal(list1) - returns an accumulative array. For example apoc.coll.runningTotal([1,2,3.5]) return [1,3,6.5]
+|label:function[]
+|label:apoc-core[]
 |xref::overview/apoc.coll/apoc.coll.set.adoc[apoc.coll.set icon:book[]]
 
 apoc.coll.set(coll, index, value) \| set index to value

docs/asciidoc/modules/ROOT/partials/generated-documentation/nav.adoc

@@ -82,6 +82,7 @@ This file is generated by DocsTest, so don't change it!
 *** xref::overview/apoc.coll/apoc.coll.remove.adoc[]
 *** xref::overview/apoc.coll/apoc.coll.removeAll.adoc[]
 *** xref::overview/apoc.coll/apoc.coll.reverse.adoc[]
+*** xref::overview/apoc.coll/apoc.coll.runningTotal.adoc[]
 *** xref::overview/apoc.coll/apoc.coll.set.adoc[]
 *** xref::overview/apoc.coll/apoc.coll.shuffle.adoc[]
 *** xref::overview/apoc.coll/apoc.coll.sort.adoc[]