Generic Functions in QPR ProcessAnalyzer

Aggregation functions

Following aggregation functions available:

• Average: Average of the items, i.e. sum of items divided by count of items. Can be used for numbers, DateTimes and TimeSpans.
• Count: Number of items. Can be used for any data.
• Median: Median, i.e. the middle value when data is sorted. If there is even number of items, the average of the two middle items. Can be used for numbers, DateTimes and TimeSpans.
• Min: Lowest/first value in the data. Can be used for data that can be sorted.
• Max: Highest/last value in the data. Can be used for data that can be sorted.
• Percentile: Can be used for numbers, DateTimes and TimeSpans.
• Sum: Sum of the items. Can be used for numbers and TimeSpans.
• StringJoin: joins array of strings together. The first parameter is a string that is placed between the joined strings.

Examples:

Sum([3, 2, 4])
Returns: 9

Count([[1, 2], [3, 4, 5]])
Returns: [2, 3]

Sum([[1, 2], [3, 4, 5]])
Returns: [3, 12]

Percentile([1,2,3,4,5], 0.75)
Return: 4

Sum([])
Returns: null

StringJoin(", ", ["one", "two", "three"])
Returns: one, two, three

When aggregating numerical values and there are null values, nulls are treated as zeros. When aggregating DateTimes and TimeSpans, and there are null values, error is given. In the Min and Max functions, nulls are ignored. Null values can be removed before aggregating (the following example shows how).

Average([1, 5, null])
Returns: 2

Average(([1, 5, null]?? _remove)._)
Returns: 3

Aggregation operations are performed to the leaf level. i.e. the deepest level in the hierarchy. When aggregating, the leaf level arrays are replaced by the aggregated values, and thus the depth of the hierarchy decreases by one. In addition to the aggregation functions, functions that modify the contents of leaf arrays (OrderBy, Distinct, ...), the operation will be performed separately for every leaf array.

OrderByValue([[4, 3], [2, 1]])
Returns: [[3, 4], [1, 2]]

Mathematical functions

Function	Parameters	Description
ArgMax (Object)	Array or hierarchical object Value expression	Returns those objects in the array giving maximum values for the given expression when evaluated in the object's context. Examples: ArgMax([5, 1, 6, 4, 3, 3, 6, 5, 4, 1, 1], _) Returns: [6, 6] ArgMax(EventLogById(1).Cases, Duration) Returns: An array of cases having the longest duration.
ArgMin (Object)	Array or hierarchical object Value expression	Returns those objects in the array giving minimum values for the given expression when evaluated in the object's context. Examples: ArgMin([5, 1, 6, 4, 3, 3, 6, 5, 4, 1, 1], _) Returns: [1, 1, 1] ArgMin(EventLogById(1).Cases, Duration) Returns: An array of cases having the shortest duration.
Ceiling (Integer)	Number (Float)	Returns the smallest integer that is greater than or equal to the specified number. Example: Ceiling(1.3) Returns: 2
Floor (Integer)	Number (Float)	Returns the largest integer that is less than or equal to the specified number. Example: Floor(1.9) Returns: 1
Round (Float)	Number of decimals (Integer)	For numbers, rounds the number to the specified number of decimal. Number of decimals can also be negative, in which case the number is rounded to the nearest tens, hundreds, thousands, etc. For DateTimes, rounds given date time by given time span or given number of seconds. Note that the number/DateTime to be rounded needs to be provided as a context object (not as a parameter). Examples: (1.254).Round(1) Returns: 1.3 (162.111111).Round(-2) Returns: 200 DateTime(2017, 1, 2, 3, 4, 5).Round(10) Returns: DateTime(2017, 1, 2, 3, 4, 10) DateTime(2017, 1, 2, 3, 4, 5).Round(TimeSpan(1)) Returns: DateTime(2017, 1, 2)

Conversion functions

Function	Parameters	Description
ToFloat (Number)	Object to convert	Converts given object to a decimal number.
ToInteger (Integer)	Object to convert	Converts given object into an integer. If the object can not be converted into an integer, an exception will be thrown. If the object as a decimal number, it will also be rounded to the nearest integer. Examples: ToInteger(1.234) Returns: 1 ToInteger(-1.5) Returns: -2 ToInteger(1313.6) Returns: 1314 ToInteger(123456789012345678) Returns: 123456789012345678 ToInteger("5") Returns: 5 ToInteger("-5") Returns: -5
ToString (String)	Object to convert	Converts given object to a string. Examples: ToString(1) + " < " + ToString(2) Returns: "1 < 2". "Case=\'" + ToString(a) + "\'" Returns: "Case='<string representation of object a>'" ToString(DateTime(2017,1,2,3,4,5,6)) Returns: "2017-01-02T03:04:05"

Miscellaneous functions

Function	Parameters	Description
Where	Condition expression	Returns the context object if the given expression evaluates to true. Examples: [1,2,3,4].Where(_>2) Returns: [3,4] EventLogById(1).Cases.Where(Duration > TimeSpan(10)) Returns all cases where duration is more than 10 days (in eventlog id 1). EventLogById(1).Events.Where(Timestamp < DateTime(2020, 1,1)) Returns all events which occurred before 1.1.2020 (in eventlog id 1).
If	Condition expression True expression False expression	If the first parameter is true, returns the value of the second parameter. Otherwise returns the value of the third parameter. The function always evaluates only either the second or third parameter, but never both. Note that the function needs to starts with a capital letter, because otherwise it's interpreted as the if operator. Examples: If(Now.Second % 2 == 0, "Even second", "Odd second") Returns: "Event second" or "Odd second" depending on the time of the evaluation. For("i", 0, i < 10, i + 1, i).If(_ % 2 == 0, _, _remove) Returns: [0, 2, 4, 6, 8]
RemoveNulls (Array)	Array	Removes all the supported null values from given hierarchical object. Never removes arrays containing removed null values. Returns given object with null values removed. Examples: RemoveNulls([1, [], [null], [2, _remove, [_empty, 3, 4], _empty, null, 5]]) Returns: [1, [], [], [2, [3, 4], 5]] RemoveNulls([""foo"":null, ""bar"":2, ""poof"": [1, _empty, 3]]) Returns: [ "foo": 0, "bar": 2, "poof": [ 1, 3 ] ]
Catch	Expression to calculate Result if exception (Object)	Calculates the given expression and if any exceptions are thrown during the calculation, catches that exception and returns the given result. Note that this function does not catch any syntactical errors. Examples: Catch(1, 1234) Returns: 1 Catch(undefined, 1234) Returns: 1234 Catch([1,2].undefined, 1234) Returns: 1234 Catch(EventLogById(-1), 1234) Returns: 1234
AsParallel	Additional parameters	Performs all the following chaining operations in parallel to improve performance. Items are divided into parts which size is determined by the ParallelTaskSize parameter, and each part is executed as an independent task in parallel. Parallel execution has a certain cost, so it might not be optimal to run each item as a separate task (increase ParallelTaskSize to decrease number of tasks). On the other hand, to large ParallelTaskSize leads to too few parallel tasks, and then all processing capacity is not used. As a parameter, takes a dictionary that accepts optional property ParallelTaskSize, which is the size of the segments the root array will be split into. If the length of the input array is not divisible by ParallelTaskSize, the last segment will have less items than this configured value. The default size is 1. Returns the original root object. Examples: Sum(Sum(([NumberRange(1, 100)].AsParallel(["ParallelTaskSize": 1]).For("i", 0, i < 100000, i + 1, i))[0])) Returns: 499995000000 The same expression without parallel processing: Sum(Sum(NumberRange(1, 100).For("i", 0, i < 100000, i + 1, i))) Returns: 499995000000 Sum([NumberRange(1, 100)].AsParallel(["ParallelTaskSize": 1]).WriteLog(_)) Returns: 5050 In addition, outputs all the numbers from 1 to 100 into log file in the order in which the tasks were executed. Count((([el.Cases].AsParallel(["ParallelTaskSize": 1000]):AnalyzeConformance(cm))[0]).Where(_==null)) Returns the number of cases conforming to a design/conformance model cm. The same expression without parallel processing: Count((el.Cases:AnalyzeConformance(cm)).Where(_==null))
IsNull (Boolean)	Value to test (Object)	Tests whether given object is null, _empty or _remove. Returns true if it is any of those. If given a hierarchical object, applies the function as described in at the leaf level. Examples: ForEach("item", [1, "a", null, _empty, _remove], IsNull(item)) Returns: [false, false, true, true, true] IsNull(["foo":[null,"a"], "bar":[2,null]]) Returns: [ HierarchicalArray("foo", [true, false]), HierarchicalArray("bar", [false, true]) ]
IsNullTop (Boolean)	Object to test (Object)	Tests whether given object is null, _empty or _remove. Returns true if it is any of those. The function does not aggregate values in hierarchical objects. Examples: ForEach("item", [1, "a", null, _empty, _remove], IsNullTop(item)) Returns: [false, false, true, true, true] IsNullTop(["foo":[null,"a"], "bar":[2,null]]) Returns: false
GroupBy	Array to group Group by expressions	Groups given array by given expressions. Returns the given array splitted into groups in a way that each specified group expression creates one level of hierarchical arrays having the root object the same as the group expression result. Examples: GroupBy([1,2,2,3,3,4,5,5,4,4,4], _) Returns: [[1:[1], 2:[2, 2], 3:[3, 3], 4:[4, 4, 4, 4], 5:[5,5]]
GroupByValue	Array to group	Groups all unique values in given array. Returns the given array in a format which has all the values in the original array only once as root objects and the root objects in the original array as contents of the arrays inside contexts. In a way, this just switches root objects of hierarchical arrays to be the actual values and actual values to be root objects (without duplicates). For every item in the array, the behavior is as follows: If the item is not an array, the value is used also as the root object of the item. If the item is an array, all the values are treated separately. If the item is a hierarchical array, its root object will be used as root object and each separate value treated separately as scalars (ending up being root objects of the resulting object). Examples: GroupByValue([1,2,2,3,3,4,5,5,4,4,4]) Returns: (The same as GroupBy([1,2,2,3,3,4,5,5,4,4,4], _)) [1:[1], 2:[2, 2], 3:[3, 3], 4:[4, 4, 4, 4], 5:[5,5]] GroupByValue([1:["a","b"],2:["b","c"],3:["c"],4:["d","e"],5:["d","d","d"]]) Returns: ["a":[1], "b":[1, 2], "c":[2, 3], "d":[4, 5, 5, 5], "e":[4]] Get count of item "2" in the array: Let(\"groupped\", GroupByValue([1,2,4,1,4,2,3,3,2,4])); Count(GetValueOfContext(2, groupped)) Returns: 3
Coalesce	Object to coalesce Result if Null	Returns the second parameter if the first parameter is null or empty. If the the given object is a hierarchical object, all the leaf level values are coalesced separately. Examples: Coalesce(0, 1) Returns: 0 Coalesce(null, 1) Coalesce(_empty, 1) Coalesce(_remove, 1) All return: 1 Coalesce([[null, 1], [null, null]], 3) Returns: [[3, 1], [3, 3]] Coalesce([[null, 1], 2], 3) Returns: [[3, 1], null] Coalesce([1, [null, 2], null], 3) Returns: [1, [null, 2], 3]
Transpose	Matrix to transpose	Transposes the given matrix. Examples: Transpose([[1,2], [3,4], [1,4]]) Returns: [[1, 3, 1], [2, 4, 4]]
GarbageCollection		Calling this function performs a garbage collection in the QPR ProcessAnalyzer Server. The function returns the maximum generation before the garbage collection was run. This function is an experimental functionality, which purpose is to investigate the memory consumption and memory handling behavior of the QPR ProcessAnalyzer Server.
GetContext	Hierarchical array	Returns the context of given hierarchical array, i.e. list of keys in the object. If the given object is not an hierarchical array, returns null. Examples: GetContext("a":1) Returns: "a" ["a":1, "b":2, 2:3].GetContext(_) Returns: ["a", "b", 2] ([1,2,3]:(_*2)).GetContext(_) Returns: [1, 2, 3] ["a":1, 2, 3].GetContext(_) Returns: ["a", null, null]
GetValueOfContext	Context object Hierarchical array	Returns the value of specified context object in given hierarchical array, i.e. the value behind the key. If the key if found multiple times, the first occurrence is returned. Returns _empty if the given key was not found. Examples: GetValueOfContext("bar", ["foo":1, "bar":2]) Returns: [2] GetValueOfContext("bar", ["foo":1, "bar":2, "bar":"second"]) Returns: [2] GetValueOfContext("test", ["foo":1, "bar":2]) Returns: _empty
WriteLog	message (String)	Writes given text into QPR ProcessAnalyzer log file. The return value of the function is the provided message parameter. Examples: WriteLog("Calculation executed.") Writes to log: Calculation executed. Sum(WriteLog([1, 2, 3, 4])) Returns: 10 Also writes an entry into the log showing the [1, 2, 3, 4] -array in the pretty printed fashion. NumberRange(0, 4).(WriteLog("Iteration #" + (_ + 1)), _) Returns: [0, 1, 2, 3, 4] Also writes the following entries into log: Iteration #1 Iteration #2 Iteration #3 Iteration #4 Iteration #5

Ordering functions

Function	Parameters	Description
OrderBy (array)	Array to order Order expression	Orders the given array using values from the given order expression. The order expression is evaluated once for each item in the array. The order expression supports all atomic (=not collection) primitive value types. Examples: OrderBy(["a", "x", "b", "z", "n", "l", "a"], _) Return: ["a", "a", "b", "l", "n", "x", "z"] OrderBy([9,8,7,6,5,4,3,2,1], _%3) Returns: [9,6,3,7,4,1,8,5,2] OrderBy([9,8,7,6,5,4,3,2,1], _%3 + _/30) Returns: [3,6,9,1,4,7,2,5,8]
OrderByDescending (array)	Array to order Order expression	Result is same as in the OrderBy function, except the order is reverse.
OrderByTop (array)	Array to order Order expression	Orders given top-level array by the value of given expression using ascending order. Supports all value types, including multi-dimensional arrays. Order expression is evaluated in the context of each array item whose value determines the order of that item. Examples: OrderByTop([[1, 2, 3], [2, 2, 2], [3, 2, 1]], _[2]) Returns: [[3, 2, 1], [2, 2, 2], [1, 2, 3]]
OrderByValue (array)	Array to order	Orders the given array using the natural order of items, for example numbers it's the increasing order, and for strings it's text ordering. OrderByValue(["a", "x", "b", "z", "n", "l", "a"]) Return: ["a", "a", "b", "l", "n", "x", "z"]
OrderByValueDescending (array)	Array to order	Result is same as in the OrderByValue function, except the order is reverse.

Looping functions

Function	Parameters	Description
For	Iterated variable name (String) Initial value for iterated property (object) Iteration condition expression Next iteration step expression Expression to calculate iterated items	Iterates the given expression until the given condition is met, and returns the results of the iterated expressions for every iteration as an array. Examples: For("i", 0, i < 4, i + 1, i) Returns: [0, 1, 2, 3] For("x", 0, x < 3, x + 1, For("y", 0, y < 3, y + 1, StringJoin(",", [x, y])) Returns: [["0,0", "0,1", "0,2"], ["1,0", "1,1", "1,2"], ["2,0", "2,1", "2,2"]] For("i", 0, i < 4, i + 1, DateTime(2010 + i)) Returns: [DateTime(2010), DateTime(2011), DateTime(2012), DateTime(2013)] For("str", "a", str != "aaaaa", str + "a", str) Returns: ["a", "aa", "aaa", "aaaa"]
ForEach	Variable to repeat (String) Array to repeat Expression to calculate repeated items	Repeats the given expression as many times there are items in the given array. Item in the array is available as the given variable in the expression. Examples: ForEach("i", [1,2,3], "Value is: " + i) Returns: Value is: 1 Value is: 2 Value is: 3 ForEach("item", EventLogById(1).Cases, Let("c" + item.Name, item)) Results: Creates expression variable variables like "c<casename>" for every case in the model. ForEach("myVariable", ["a", "b", "c"], myVariable + myVariable) Returns: aa bb cc
NumberRange	Start (Number) End (Number) Interval (Number)	Creates an array of numbers within given range with the given interval. Interval parameter is optional, and by default it is one. Examples: NumberRange(1, 3) Returns: [1, 2, 3] NumberRange(1, 3, 0.5) Returns: [1, 1.5, 2, 2.5, 3] NumberRange(1, 3, 0.8) Returns: [1, 1.8, 2.6]
Repeat	Number of times to repeat (Integer) Expression to repeat	Repeats the defined expression the defined number of times. Examples: Repeat(3, "Repeat me!") Returns: "Repeat me!" "Repeat me!" "Repeat me!" Repeat(1, 5) Returns 5
TimeRange	Start (DateTime) End (DateTime) Interval (Timespan)	Generates a timestamp array starting from the start timestamp with the defined interval, and ending when the end timestamp is reached. Note that this function only creates timestamps with equal durations, so it's not possible to e.g. create timestamps for each month (to do that, you can use the loops). Generate datetimes starting from Monday 2017-01-01 and ending to Monday 2017-12-31 including all Mondays between them: Timerange(Datetime(2018,1,1), Datetime(2018,1,1), Timespan(7))

Recursion functions

Function	Parameters	Description
Recurse	Expression to call recursively Stop condition expression Maximum depth (Integer)	Evaluates the given expression recursively until given condition or recursion depth is met. The function returns all the traversed objects in a single array. When the stop condition expression evaluates to false, it will stop the current recursion without including the false evaluated object into the result. Default stop condition is !IsNull(_). The default maximum depth is 1000. Examples: (1).Recurse(_ + 1, _ < 5) Returns: [1, 2, 3, 4] event.Recurse(NextInCase) Returns: An array of all the events following given event inside the same case. event.Recurse(NextInCase, Type.Name != "Invoice") Returns: An array of all the events following given event inside the same case until event whose type name is "Invoice", which will itself not be included into the result. event.Recurse(NextInCase, Type.Name != "Invoice", 2) Returns: An array of all the events following given event inside the same case until event whose type name is "Invoice" or until the recursion depth of 2 has been reached, which will itself not be included into the result.
RecurseWithHierarchy	Expression to call recursively Stop condition expression Maximum depth (Integer)	Evaluates the given expression recursively until given condition or recursion depth is met. The function returns the traversed object hierarchy. When the stop condition expression evaluates to false, it will stop the current recursion without including the false evaluated object into the result. Default stop condition is !IsNull(_). The default maximum depth is 1000. Examples: [1,2].RecurseWithHierarchy([1,2], false, 2) Returns: [1:[1:[1,2],2:[1,2]],2:[1:[1,2], 2:[1,2]]] (1).RecurseWithHierarchy(_ + 1, _ < 5) Returns: 1:[2:[3:[4]]] RemoveLeaves(eventLog.Flows:From.Where(IsNull(_))).To.RecurseWithHierarchy(OutgoingFlows.To, !IsNull(_), 2) Returns: A hierarchy consisting of all the starter events of given event log and recursively all the event types reachable from them via flows until depth of 2 is reached.
RecursiveFind	Expression to call recursively Find condition expression Stop condition expression Continue after finding (Boolean) Maximum depth (Integer)	Evaluates given expression recursively until given condition or recursion depth is met. The function collects all the traversed objects that match the given find expression along the way. When the find condition expression evaluates to true for the current object, it causes the following: Current object is added to the result array returned by the function call If continue after finding is false, the recursion will not be continued on this branch When the stop condition expression evaluates to false, it will stop the current recursion without including the false evaluated object into the result. Default stop condition is !IsNull(_). The default maximum depth is 1000. Continue after finding tells should the recursion be continued after a match has been found in the current branch. Examples: (1).RecursiveFind(_ + 1, _ == 100) Returns: 100 eventLog.Cases:GetAt(0, Events).RecursiveFind(NextInCase, Organization=="Finance", !IsNull(_)) Returns: For each case, returns the first (by time) event whose organization equals to "Finance". eventLog.Cases:Events.Where(Organization=="Finance") eventLog.Cases:GetAt(0, Events).RecursiveFind(NextInCase, Organization=="Finance", true, true) Returns: Both return for each case all events whose organization equals to "Finance".

Hierachical object functions

Function	Parameters	Description
FindRepeats	Array Minimum repeated length (Integer) Longest repeat length (Integer)	Searches for repeating patterns in given array. Parameters: Array to search the patterns in. Minimum integer length of a repeat that can be returned by this function (default = 0). Boolean value indicating whether to return all the repeating patterns (true) or only the ones having the longest length (false) (default = false) Returns an array of arrays indicating the repeating patterns and their positions in the array formatted as follows: Every repeating pattern has its own entry in the top-level array. Every repeating pattern item in the top-level array is formatted internally as an array consisting of: An array constining the repeating pattern itself. An array consisting of all the indexes from which this pattern was found to start from. Allows overlapping patterns. Results are sorted primarily by the length of the pattern and secondarily by the number of indexes the pattern was found in. Examples: FindRepeats([0, 1, 2, 0, 1, 2]) Returns: [ [[0, 1, 2], [0, 3]], [[0, 1], [0, 3]], [[1, 2], [1, 4]], [[0], [0, 3]], [[1], [1, 4]], [[2], [2, 5]] ] FindRepeats([0, 1, 2, 0, 1, 2], 0, true) Returns: [[[0, 1, 2], [0, 3]]] FindRepeats([1, "b", DateTime(2017), 1, "b", DateTime(2017)], 3) Returns: [[1, "b", DateTime(2017)], [0, 3]]
Flatten	Array or hierarchical object Include context object (boolean)	Collects all the actual leaf values from given array, array of arrays or hierarchical object and returns them in a single array. If given a hierarchical object, this function collects actual leaf values instead of leaf level values. Elements in the returned array are in the same order they were found when traversing the input object using depth first search. When context object is included, should context objects in the internal nodes of a hierarchical object be also included into the result. Default is false. Examples: Flatten(1) Returns: 1 Flatten([1, 2]) Returns: [1,2] Flatten([[[1, 2],[3, 4]],[[5, 6]]]) Returns: [1, 2, 3, 4, 5, 6] Flatten([[1, 2], 3]) Returns: [1, 2, 3] Flatten([[1,2,3,4], null, [5], [1, null]]) Returns: [1, 2, 3, 4, null, 5, 1, null] Flatten(["a":1, "b":2]) Flatten(["a":1, "b":2], false) Returns: [1, 2] Flatten(["a":1, "b":2], true) Returns: ["a", 1, "b", 2]
RemoveLeaves	Hierarchical object	Remove one level of hierarchy from a hierarchical object replacing all the bottom level hierarchical arrays with the context objects of the hierarchical arrays. Returns the given object with all the bottom level hierarchical arrays with the context objects of the hierarchical arrays. Examples: RemoveLeaves(["foo":1, "bar":2]) Returns: ["foo", "bar"] RemoveLeaves(eventLog.Flows:From.Where(IsNull(_))) Results: All the flows starting the cases in the event log.
ReplaceLeafValues	Array or hierarchical object Variable name used in the iteration (String) Expression to get the result of each iteration Number of levels up from the leaf level to operate (Integer)	Replace all leaf values of given array or hierarchical object at given levels up from the leaf level with results of given expression. Examples: ReplaceLeafValues([1,2, null], "x", If(IsNull(x), null, x+1), 0) Result: [2, 4, null] ReplaceLeafValues([[[1,2],[2,3]],[[3,4],[4,5]]], "x", Flatten(x), 0) Result: [[[[1],[2]],[[2],[3]]],[[[3],[4]],[[4],[5]]]] ReplaceLeafValues([[[1,2],[2,3]],[[3,4],[4,5]]], "x", Flatten(x), 1) Result: [[[1,2],[2,3]],[[3,4],[4,5]]] ReplaceLeafValues([[[1,2],[2,3]],[[3,4],[4,5]]], "x", Flatten(x), 2) Result: [[1,2,2,3],[3,4,4,5]] ReplaceLeafValues([[[1,2],[2,3]],[[3,4],[4,5]]], "x", Flatten(x), 3) Result: [1,2,2,3,3,4,4,5]
SliceMiddle	Start index for the range to extract (Integer) End index for the range to extract (Integer) Levels up in the hierarchy (Integer) Array to slice	Extracts a continuous range of an array or hierarchical object. If given a hierarchical object, applies the function at the level that is specified levels level up from the leaf level. Start index: Negative value means that the index is counting from the end of the array. If array does not have element at this given index, empty array is returned. End index: not included into the extracted range. Negative value means that the index is counting from the end of the array. If array does not have element at this given index, all the elements to the end from the start index will be extracted. Levels up: At which level of the hierarchical object are we operating (number of levels up from the leaf level). Should be at least 1 (since 0 level does not contain arrays). Examples: SliceMiddle(1, 2, 1, [[0, 1, 2, 3], [4, 5, 6, 7]]) Returns: [[1], [5]] SliceMiddle(2, 4, 1, [[0, 1, 2, 3], [4, 5, 6, 7]]) Returns: [[2, 3], [6, 7]] SliceMiddle(0, 1, 2, [[0, 1, 2, 3], [4, 5, 6, 7]]) Returns: [0, 1, 2, 3] SliceMiddle(3, 5, 1, [0, 1, 2, 3, 4, 5, 6, 7]) Returns: [3, 4] SliceMiddle(-3, -1, 1, [0, 1, 2, 3, 4, 5, 6, 7]) Returns: [5, 6] SliceMiddle(3, -1, 1, [0, 1, 2, 3, 4, 5, 6, 7]) Returns: [3, 4, 5, 6]

Variable handling functions

Function	Parameters	Description
Def	Function name (String) Variable 1 name (String) Variable 2 name (String) ... Function expression	Creates a new user defined function. Parameters starting from the second, are the parameters that user gives when calling the function. The last parameter is the expression to evaluate when the function is called. In that definition expression the named parameters are used. Instead of the Def function, a recommended way to define functions is the lambda syntax. Examples: Def("Inc", "a", a + 1); Inc(2); Returns: 3 Def("Add", "a", "b", a + b); [1, 2, 3].Add(_, 2); Returns: [3, 4, 5] Def("AddSelf", "b", _ + b); [1, 2, 3].AddSelf(2); Returns: [3, 4, 5] Def("Fib", "a", If(a < 2, 1, Fib(a - 1) + Fib(a - 2))); Fib(10); Returns: 89
Let	Variable name (String) Variable value (Object)	Defines a user defined variable to the scope where the Let function is located. Note that the function name needs to starts with a capital letter, because otherwise it's interpreted as a let operator. Examples: Let("var1", "Orange"); "Value is " + var1; Returns: Value is Orange
Set	Variable name (String) Variable value (Object)	Sets a value for an existing user defined variable. The variable to set must have been created previously in some visible scope. Instead of the Set function, a recommended way to set variables, is the assignment operator.
Variable	Variable name (String)	Function to get a variable value. The function is needed when there are spaces in a variable name, because that variable cannot be referenced otherwise in the expressions.