Container Functions
List of functions
append | isEmpty |
binarySearch | length |
clear | poll |
containsAll | pop |
containsKey | push |
containsValue | remove |
copy | reverse |
getKeys | sort |
getValues | toMap |
insert |
When working with containers (list
, map
and record
),
you will typically use the 'contained in' function call - in
.
This call identifies whether a value is contained in a list or a map of other values.
There are two syntactic options:
boolean myBool; string myString; string[] myList; map[string, long] myMap; ...
myBool = myString.in(myList)
myBool = in(myString,myList);
myBool = in(myString,myMap);
In the table below, examine (im)possible ways of using in
:
Code | Working? |
---|---|
'abc'.in(['a', 'b']) | |
in(10, [10, 20]) | |
10.in([10, 20]) |
As for lists and maps in metadata, use in
like this:
Code | Comment |
---|---|
in('abc', $in.0.listField) | operator syntax for list field |
in('abc', $in.0.mapField) | operator syntax for map field, searching for a key of map entry |
Note | |
---|---|
The operator syntax has a disadvantage. Searching through lists will always be slow (since it has to be linear).
It is better to use the |
Functions you can use with containers
append
<element type>[] append(
<element type>[] arg, <element type>
list_element)
;
The append()
function adds element to the list.
The function takes a list of any element data type specified as the first argument and adds it to the end of a list of elements of the same data type specified as the second argument. The function returns the new value of list specified as the first argument.
This function is an alias of the push(<element type>[], <element type>)
function.
From the list point of view, append()
is much more natural.
If the given list has a null
reference, the function fails with an error.
Compatibility
The append(E[],E)
function is available
since CloverETL 3.0.0.
Example 67.170. Usage of append
The function append(["a", "b", "d"], "c")
returns [a, b, d, c]
.
binarySearch
integer binarySearch(
<element type>[] arg, <element type>
key)
;
The binarySearch()
function searches a specified list
for a specified object using the binary search algorithm.
The elements of the list must be comparable and the list must be sorted in ascending order. If it is not sorted, the results are undefined.
Returns the index of the search key (≥ 0) if it is contained in the list. Otherwise, returns a negative number defined as (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the list.
If the list contains multiple objects equal to the search key, there is no guarantee which one will be found.
The function fails if either of the arguments is null
or if <element type> is not comparable.
Compatibility
The isEmpty()
function is available
since CloverETL 4.1.0-M1.
Example 67.171. Usage of binarySearch
binarySearch(["a", "b", "d"], "b")
returns 1
,
because the index of "b"
is 1.
binarySearch(["a", "b", "d"], "c")
returns -3
,
because "c"
would be inserted at position 2.
See also: containsValue
clear
void clear(
<element type>[] arg)
;
The clear()
function empties a given list argument of any element data type.
It returns void.
If the given list has a null
reference, the function fails with an error.
Compatibility
The clear(E[])
and clear(map[K,V])
functions are available
since CloverETL 3.0.0.
Example 67.172. Usage of clear
The function clear(["a", "b"])
returns []
.
void clear(
map[<type of key>,<type of value>] arg)
;
The clear()
function empties a given map argument.
It returns void.
If a given map has a null
reference, the function fails with an error.
Example 67.173. Usage of clear
There is map[string, string] map2
with values
map2["a"] = "aa"
and map2["b"] = "bbb"
.
The call of function clear(map2)
results into {}
.
containsAll
boolean containsAll(
<element type>[] list, <element type>[] subList)
;
The containsAll()
function returns true
if the list specified as the first argument contains every element of the list specified
as the second argument, i.e. the second list is a sublist of the first list.
If one of the given list has a null
reference, the function fails with an error.
Compatibility
The containsAll(E[],E[])
function is available
since CloverETL 3.3.x.
Example 67.174. Usage of containsAll
The function containsAll([1, 3, 5], [3,5])
returns true
.
The function containsAll([1,3,5], [2,3,5])
returns false
.
See also: containsKey, containsValue
containsKey
boolean containsKey(
map[<type of key>,<type of value>] map, <type of key> key)
;
The containsKey()
function returns true
,
if the specified map contains a mapping for the specified key.
If a given map has a null
reference, the function fails with an error.
Compatibility
The containsKey(map[K,V],K)
function is available
since CloverETL 3.3.x.
Example 67.175. Usage of containsKey
Let us have a map map[integer, integer] map1;
map1[1] = 17;
map1[5] = 19;
.
The function containsKey(map1, 1)
returns true
.
The function containsKey(map1, 2)
returns false
.
See also: containsValue, getKeys
containsValue
boolean containsValue(
map[<type of key>,<type of value>] map, <type of value> value)
;
boolean containsValue(
<element type>[] list, <element type> value)
;
The containsValue(map, value)
function returns true
if the specified map maps one or more keys to the specified value.
The containsValue(list, value)
function returns true
if the specified list contains the specified value.
If the given container is a null
reference, the function fails with an error.
Compatibility
The containsValue(map[K,V],V)
function is available
since CloverETL 3.3.x.
The function containsValue(E[],E)
is available
since CloverETL 4.0.0.
Example 67.176. Usage of containsValue
Let us have a map map[integer, integer] map1; map1[1] = 17; map1[5] = 19;
.
The function containsValue(map1, 23)
returns false
.
The function containsValue(map1, 17)
returns true
.
The function containsValue([10, 17, 19, 30], 23)
returns false
.
The function containsValue([10, 17, 19, 30], 17)
returns true
.
See also: containsKey, getValues binarySearch
copy
<element type>[] copy(
<element type>[] to, <element type>[] from)
;
The copy()
function copies items from one list to another.
The function accepts two list arguments of the same data types. The function takes the second argument, adds it to the end of the first list and returns the new value of the list specified as the first argument.
If one of the given lists has a null
reference, the function fails with an error.
Compatibility
The copy(E[],E[])
function is available
since CloverETL 3.0.0.
Example 67.177. Usage of copy
There are two lists.
The list s1 = ["a", "b"]
and the list s2 = ["c", "d"]
.
The function copy(s1, s2)
returns ["a", "b", "c", "d"]
.
The list s1
has been modified and contains values ["a", "b", "c", "d"]
.
map[<type of key>, <type of value>] copy(
map[<type of key>, <type of value>] to, map[<type of key>, <type of value>] from)
;
The copy()
function accepts two map arguments of the same data type.
The function takes the second argument, adds it to the end of the first map replacing existing key mappings
and returns the new value of the map specified as the first argument.
If one of the given maps has a null
reference, the function fails with an error.
If some key exists in both maps, the result will contain value from the second one.
Example 67.178. Usage of copy
Let us have following lines of code.
map[string, string] map1;
map1["a"] = "aa";
map1["b"] = "bbb";
map[string, string] map2;
map2["c"] = "cc";
map2["d"] = "ddd";
$out.0.field1 = map1;
$out.0.field2 = map2;
$out.0.field3 = copy(map1, map2);
$out.0.field4 = map1;
$out.0.field5 = map2;
The field field1
contains {a=aa, b=bbb}
.
The field field2
contains {c=cc, d=ddd}
.
The field field3
contains {a=aa, b=bbb, c=cc, d=ddd}
.
The field field4
contains {a=aa, b=bbb, c=cc, d=ddd}
.
The function copy
copies values from the second argument
(map2
) to the first argument (map1
).
The field field5
contains {c=cc, d=ddd}
.
getKeys
<type of key>[] getKeys(
map[<type of key>, <type of value>] arg)
;
The getKeys()
function returns a list
of a given map's keys.
Remember the list has to be the same type as map's keys.
If a given map has a null
reference, the function fails with an error.
Compatibility
The getKeys()
function is available since CloverETL 3.3.x.
Example 67.179. Usage of getKeys
map[string, integer] myMap;
myMap["first"] = 1; // filling the map with values
string[] listOfKeys = getKeys(myMap);
The listOfKeys
contains [first]
See also: containsKey, containsValue, getValues
getValues
<type of value>[] getValues(
map[<type of key>, <type of value>] arg)
;
The function getValues()
returns values contained in map arg
as a list.
If the arg
is an empty map, the function getValues()
returns empty list.
If the arg
is null
, function getValues()
fails.
Compatibility
The getValues()
function is available
since CloverETL 4.0.0.
Example 67.180. Usage of getValues
map[string, string] greek; greek["a"] = "alpha"; greek["b"] = "beta"; string[] values = getValues(greek);
The function getValues()
returns [alpha, beta]
.
map[string,string] m; string[] values = getValues(greek);
The function getValues()
returns empty list.
map[string,string] m = null; string[] values = getValues(greek);
The function getValues()
having a null
argument fails.
See also: containsKey, getKeys, toMap,
insert
<element type>[] insert(
<element type>[] arg, integer
position, <element type>
newelement)
;
The insert()
function inserts element into the list.
The item specified as the third argument is inserted to a position specified as the second argument in a list of elements specified as the first argument. The list specified as the first argument is changed to this new value and it is returned by the function. The list of elements and the element to insert must be of the same data type. Remember that the list elements are indexed starting from 0.
If a list given as the first argument has a null
reference,
the function fails with an error.
Compatibility
The insert(E[],integer,E)
and insert(E[],integer,E[])
functions are available since CloverETL 3.0.0.
Example 67.181. Usage of insert
There is a list string[] s1 = ["a", "d", "c"]
.
The function insert(s1, 1, "b")
returns [a, b, d, c]
.
The original list s1
has been modified too.
isEmpty
boolean isEmpty(
<element type>[] arg)
;
The isEmpty()
function checks whether a given list is empty.
If the list is empty, the function returns true
,
otherwise the function returns false
.
If a given list has a null
reference, the function fails with an error.
Compatibility
The isEmpty(E[])
and isEmpty(map[K,V])
functions are available since CloverETL 3.0.0.
Example 67.182. Usage of isEmpty
The function isEmpty(["a", "b"])
returns false
.
The function isEmpty
in the following code returns true
.
string[] s1; isEmpty(s1);
boolean isEmpty(
map[<type of key>,<type of value>] arg)
;
The isEmpty()
function checks whether a given map is empty.
If the map is empty, the function returns true
otherwise the function returns false
.
If a given map has a null
reference, the function fails with an error.
Example 67.183. Usage of isEmpty
map[string, integer] map1; $out.0.field1 = isEmpty(map1); map1["a"] = 1; $out.0.field2 = isEmpty(map1);
The field field1
is true
,
the field field2
is false
.
length
integer length(
structuredtype arg)
;
The length()
function returns a number of elements
forming a given structured data type.
The argument can be one of following: string
,
<element type>[]
,
map[<type of key>,<type of value>]
or record
.
If a given string, list or map has a null
reference,
the function returns 0
.
Compatibility
The length(E[])
and length(map[K,V])
functions are available since CloverETL 3.0.0.
Example 67.184. Usage of length:
The function length(["a", "d", "c"])
returns 3
.
See also: String functions: length, Record functions: length
poll
<element type> poll(
<element type>[] arg)
;
The poll()
function removes the first element from a given list
and returns this element.
The list specified as the argument changes to this new value (without the removed first element).
If a given list has a null
reference, the function fails with an error.
Compatibility
The poll(E[])
function is available
since CloverETL 3.0.0.
Example 67.185. Usage of poll
The function poll(["a", "d", "c"])
returns a
.
The list given as argument contains ["d", "c"]
after the function call.
pop
<element type> pop(
<element type>[] arg)
;
The pop()
function removes the last element from a given list
and returns this element.
The list specified as the argument changes to this new value (without the removed last element).
If a given list has a null
reference, the function fails with an error.
Compatibility
The pop(E[])
function is available
since CloverETL 3.0.0.
Example 67.186. Usage of pop
The function
pop(["a", "b", "c"])
returnsc
.The function
pop
modifies lists1
:string[] s1 = ["a", "b", "c"]; $out.0.field1 = s1; $out.1.field2 = pop(s1); $out.0.field3 = s1;
field1
on first output port contains["a", "b", "c"]
.field2
on second output port containsc
.field3
on first output port contains["a", "b"]
.
push
<element type>[] push(
<element type>[] arg, <element type>
list_element)
;
The push()
function adds the element to the end of the list.
The element to be added is specified as the second argument and the list is specified as the first argument. Having added the item, the list is returned. The element to add must have the same data type as the elements of the list.
This function is an alias of the append(<element type>[], <element type>)
function.
From the stack/queue point of view, push()
is much more natural.
If a given list has a null
reference, the function fails with an error.
Compatibility
The push(E[], E)
function is available
since CloverETL 3.0.0.
Example 67.187. Usage of push
The function push(["a", "b", "c"], "e")
returns ["a", "b", "c", "e"]
.
See the following code:
string[] s1 = ["a", "d", "c"]; $out.0.field1 = push(s1, "e"); $out.0.field2 = s1;
The field field2
will contain ["a", "b", "c", "e"]
as the s1
has been modified by push
.
remove
<element type> remove(
<element type>[] arg, integer
position)
;
<value type> remove(
map[<key type>, <value type>] arg, <key type>
key)
;
The remove()
function removes:
from a given list the element at the specified
position
and returns the removed element.The list specified as the first argument changes its value to the new one. List elements are indexed starting from 0.
If a given list has a
null
reference, the function fails with an error.from a given map the key/value pair identified by the
key
and returns the value.
Compatibility
The remove(E[],integer)
function is available
since CloverETL 3.0.0.
The remove(map[K,V],K)
function is available
since CloverETL 5.0.0.
Example 67.188. Usage of remove - list
The function remove(["a", "b", "c"], 1)
returns b
.
string[] s1 = ["a", "b", "c"]; $out.0.field1 = s1; $out.1.field2 = remove(s1, 1); $out.0.field3 = s1;
The field field1
contains whole list ["a", "b", "c"]
.
The field field2
contains b
.
field3
contains ["a", "c"]
.
Example 67.189. Usage of remove - map
map[string, integer] aMap; aMap["a"] = 1; aMap["b"] = 2; aMap["c"] = 3; integer deletedValue = remove(aMap,"b"); $out.0.value = aMap["a"]; // will be 1 $out.1.value = aMap["b"]; // will be null $out.2.value = aMap["c"]; // will be 3
reverse
<element type>[] reverse(
<element type>[] arg)
;
The reverse()
function reverses the order of elements of a given list
and returns such new value of the list specified as the first argument.
If a given list has a null
reference, the function fails with an error.
Compatibility
The reverse(E[])
function is available
since CloverETL 3.1.2.
Example 67.190. Usage of reverse
The function reverse(["a", "b", "c"])
returns ["c", "b", "a"]
.
sort
<element type>[] sort(
<element type>[] arg)
;
The sort()
function sorts the elements of a given list
in ascending order according to their values and returns such new value of the list
specified as the first argument.
Null values are listed at the end of the list, if present.
If a given list has a null
reference, the function fails with an error.
Compatibility
The sort()
function is available
since CloverETL 3.0.0.
Example 67.191. Usage of sort
The function sort(["a", "e", "c"])
returns ["a", "c", "e"]
.
See also: reverse
toMap
map[<type of key>,<type of value>] toMap(
<type of key>[] keys, <type of value>[] values)
;
map[<type of key>,<type of value>] toMap(
<type of key>[] keys, <type of value> value)
;
The function toMap(k[], v[])
converts a list of keys
and lists of values
to the map.
The function toMap(k[], v)
converts a list of keys
and value
to the map.
The keys
is a list containing the keys of the returned map.
The values
is a list of values corresponding to the keys.
If only one value
is defined, the value
corresponds
to all keys in the returned map.
The data types of list of keys must correspond to the data type of key in the map, the data type(s) of value(s) must correspond to the data type of values in the map.
The length of the list of keys (keys
argument)
must be equal to the length of list of the values (values
argument).
If the parameter keys
is null
, the function fails.
If the parameter values
is null
,
the function toMap(<type of key>[],<type of value>[])
fails.
If the parameter value
is null,
the function toMap(<type of key>[],<type of value>)
returns a map having null
for all keys.
Compatibility
The toMap()
function is available
since CloverETL 4.0.0.
Example 67.192. Usage of toMap
string[] alphaValues = ["alpha", "bravo", "charlie", "delta"]; string[] abcKeys = ["a", "b", "c", "d"]; map[string, string] alphabet = toMap(abcKeys, alphaValues);
The map alphabet
has the value alpha
accessible under the key "a"
,
bravo
accessible under the key "b"
, etc.
string[] alphaValues = ["alpha", "bravo", "charlie", "delta"]; string[] abcKeys = ["a", "b", "c"]; map[string, string] alphabet = toMap(abcKeys, alphaValues);
The function toMap()
in this example fails
as the list of keys (abcKeys
) and the list of values (alphaValues
)
are of the different size.
string[] s = null; map[string, string] result = toMap(abcKeys, s);
The function toMap()
fails in this example.
The list of values cannot be null
.
string[] keys; string[] values; map[string, string] result = toMap(keys, values);
The result
is an empty map.
The second argument of the function is a single value; therefore, it can be null
.
string[] products = ["ProductA", "ProductB", "ProductC"]; map[string, string] availability = toMap(products, "available");
The variable availability
contains {ProductA=available, ProductB=available, ProductC=available}
.
All products all available.
string[] keys = ["a", "b", "c"]; string val = null; map[string, string] result = toMap(keys, val);
The map result
has three values: {a=null, b=null, c=null}
.
string[] keys; string valueNull = null; map[string, string] result = toMap(keys, valueNull);
The result
is an empty list.