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$keys

Signature: $keys(object) Parameters:
  • object - The source object to get the keys from.
Returns an array containing the keys in the object. If the argument is an array of objects, then the array returned contains a de-duplicated list of all the keys in all of the objects.

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$lookup

Signature: $lookup(object, key) Parameters:
  • object - An object to search for a key in.
If the object argument is an array of objects, then all of the objects in the array are searched
  • key - A key to search for.
Returns the value associated with key in object. If the first argument is an array of objects, then all of the objects in the array are searched, and the values associated with all occurrences of key are returned.

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$spread

Signature: $spread(object) Parameters:
  • object - An object to convert.
If the object parameter is an array of objects, then the resultant array contains an object for every key/value pair in every object in the supplied array. Splits an object containing key/value pairs into an array of objects, each of which has a single key/value pair from the input object. If the parameter is an array of objects, then the resultant array contains an object for every key/value pair in every object in the supplied array.

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$merge

Signature: $merge(object1, ...) Parameters:
  • object1 - An object to merge.
Merges an array of objects into a single object containing all the key/value pairs from each of the objects in the input array. If any of the input objects contain the same key, then the returned object will contain the value of the last one in the array. It is an error if the input array contains an item that is not an object.

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$each

Signature: $each(object, function) Parameters:
  • object - An object to process.
  • function - The function parameter will get invoked with two arguments:
function(value, name) where the value parameter is the value of each name/value pair in the object and name is its name. The name parameter is optional. Returns an array containing the values return by the function when applied to each key/value pair in the object. The function parameter will get invoked with two arguments: function(value, name) where the value parameter is the value of each name/value pair in the object and name is its name. The name parameter is optional.
ExpressionResult
{'$each(Address, function($v, $k) {$k & ": " & $v})'}["Street: Hursley Park", "City: Winchester", "Postcode: SO21 2JN"]

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$error

Signature: $error(message) Parameters:
  • message - An error message to throw.
Deliberately throws an error with an optional message

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$assert

Signature: $assert(condition, message) Parameters:
  • condition - A condition expression to assert.
  • message - An error message to throw on condition assertion failure
If condition is true, the function returns undefined. If the condition is false, an exception is thrown with the message as the message of the exception.

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$type

Signature: $type(value) Parameters:
  • value - A value to get the type of.
Evaluates the type of value and returns one of the following strings:
  • "null"
  • "number"
  • "string"
  • "boolean"
  • "array"
  • "object"
  • "function" Returns (non-string) undefined when value is undefined.