Functions that can be used with different data types.

len(variable)

if variable is primitive string, returns the length of the input string
if variable is primitive list, returns the length of the list
if variable is primitive map, returns the number of key-value pairs in the map
if variable is json array, returns the number of elements in the array
if variable is json object, returns the number of key-value pairs in the object
if variable is Tuple, returns the number of elements in the tuple
if variable is Map, returns the number of key-value pairs in the map
if variable is Table, returns row count of the table
if variable is MetricStream, returns the number of data series in the metric
if variable is Alert, returns the number of entries in the alert
else return 0

len("Hello") // return an int64 value of 5
len([1, 2, 3]) // return an int64 value of 3
len({Name: "foo", Domain: "@gmail.com"}) // return an int64 value of 2

append(list, element)

if list is primitive string and element is primitive string, return a new string.
if list is primitive list type and element is primitive value, appends element to the primitive value list
if list is primitive json type and element is primitive value, appends element to the json array
if list is tuple type, append element to the tuple
else return error

let s = "ab"  
s = append(s, "cd") // s is now the string "abcd"

let src = [1, 2, 3, 4]  
append(src, 5) // src is still [1, 2, 3, 4] as it's value is not set to after append  
src = append(src,5) // src is now [1, 2, 3, 4, 5]

typeof(variable)

if variable is primitive value, returns the type of the primitive value: "string", "int64", "float64", "bool", "null", "undefined", "list", "map", "jsonObj", "jsonArray"
else return the type of the object: "Tuple", "Map", "Lambda", "Table", "MetricStream", "Alert"

typeof(2) // return the string "int64"  
typeof([1, 2, 3]) // return the string "list"