Abs returns the absolute value of the input.

AllFalse takes a collection of Boolean values and returns true if all the items are false.

AllTrue Takes a collection of Boolean values and returns true if all the items are true.

AnyFalse takes a collection of Boolean values and returns true if any of the items are false.

AnyTrue takes a collection of Boolean values and returns true if any of the items are true.

Ceiling returns the first integer greater than or equal to the input.

Children returns a collection with all immediate child nodes of all items in the input collection with no specific order.

Contains returns true if the input string contains the given substring.

ConvertsToBoolean checks if the input can be converted to a Boolean FHIRPath docs here: https://hl7.org/fhirpath/N1/#convertstoboolean-boolean.

ConvertsToDate checks if the input can be converted to a Date FHIRPath docs here: https://hl7.org/fhirpath/N1/#convertstodate-boolean.

ConvertsToDateTime checks if the input can be converted to a Time FHIRPath docs here: https://hl7.org/fhirpath/N1/#convertstodatetime-boolean.

ConvertsToDecimal checks if the input can be converted to a Decimal FHIRPath docs here: https://hl7.org/fhirpath/N1/#convertstodecimal-boolean.

ConvertsToInteger checks if the input can be converted to an Integer FHIRPath docs here: https://hl7.org/fhirpath/N1/#convertstointeger-boolean.

ConvertsToQuantity checks if the input can be converted to a Quantity FHIRPath docs here: https://hl7.org/fhirpath/N1/#convertstoquantityunit-string-boolean.

ConvertsToString checks if the input can be converted to a String FHIRPath docs here: https://hl7.org/fhirpath/N1/#convertstostring-string.

ConvertsToTime checks if the input can be converted to a Time FHIRPath docs here: https://hl7.org/fhirpath/N1/#convertstotime-boolean.

Count returns the integer count of the number of items in the input collection.

Descendants returns a collection with all descendant nodes of all items in the input collection.

Distinct returns the set of elements that are distinct and unique from the input by applying equality-operation tests.

Empty evaluates the expression args[0] on each input item, returns whether none of the items causes the expression to evaluate to true.

EndsWith returns true if the input string ends with the given prefix.

Exclude returns the set of elements that are not in the other collection.

Exists evaluates the expression args[0] on each input item, returns whether there exists at least one item that cause the expression to evaluate to true.

Exp returns e raised to the power of the input.

Extension is syntactic sugar over `extension.where(url = ...)`, and is specific to the R4 extensions for FHIRPath (as oppose to being part of the N1 normative spec).

First Returns a collection containing only the first item in the input collection.

Floor returns the first integer less than or equal to the input.

IndexOf returns the 0-based index of the first position in which the substring is found in the input string, or -1 if it is not found.

Intersect Returns the set of elements that are in both collections.

IsDistinct queries whether the input collection is a set of fully distinct and unique values.

Last Returns a collection containing only the last item in the input collection.

Length returns the length of the input string.

Ln returns the natural logarithm of the input number.

Log returns the logarithm base of the input number.

Lower returns the input string with all characters converted to lower case.

Matches returns true when the value matches the given regular expression.

Not returns the boolean inverse of the singleton input collection.

Now returns the current time as a system.DateTime object.

Power returns a number to the exponent power.

Replace returns the input string with all instances of pattern replaced with substitution.

ReplaceMatches matches the input using the regular expression in regex and replaces each match with the substitution string.

Round rounds the decimal to the nearest whole number using a traditional round (i.e.

Select evaluates the expression args[0] on each input item.

Skip Returns a collection containing all but the first num items in the input collection.

Sqrt returns the square root of the input number as a Decimal.

StartsWith returns true if the input string starts with the given prefix.

Substring returns the part of the string starting at position start (zero-based).

Tail Returns a collection containing all but the first item in the input collection.

Take Returns a collection containing the first num items in the input collection, or less if there are less than num items.

TimeOfDay returns the current time as a system.Time object.

ToBoolean converts the input to a Boolean FHIRPath docs here: https://hl7.org/fhirpath/N1/#toboolean-boolean.

ToChars returns the list of characters in the input string.

ToDate converts the input to a Date FHIRPath docs here: https://hl7.org/fhirpath/N1/#todate-date.

ToDateTime converts the input to a Date FHIRPath docs here: https://hl7.org/fhirpath/N1/#todatetime-datetime.

Today returns the current date as a system.Date object.

ToDecimal converts the input to a Decimal FHIRPath docs here: https://hl7.org/fhirpath/N1/#todecimal-decimal.

ToInteger converts the input to an Integer FHIRPath docs here: https://hl7.org/fhirpath/N1/#tointeger-integer.

ToQuantity converts the input to a Quantity FHIRPath docs here: https://hl7.org/fhirpath/N1/#toquantityunit-string-quantity.

ToString converts the input to a String FHIRPath docs here: https://hl7.org/fhirpath/N1/#tostring-string.

ToTime converts the input to a Time FHIRPath docs here: https://hl7.org/fhirpath/N1/#totime-time.

Truncate returns the integer portion of the input.

Upper returns the input string with all characters converted to upper case.

Where evaluates the expression args[0] on each input item, collects the items that cause the expression to evaluate to true.

DefaultQuantityUnit is defined by the following FHIRPath rules: the item is an Integer, or Decimal, where the resulting quantity will have the default unit ('1') the item is a Boolean, where true results in the quantity 1.0 '1', and false results in the quantity 0.0 '1' FHIRPath docs here: https://hl7.org/fhirpath/N1/#toquantityunit-string-quantity.

Error constants.

Error constants.