The FHIRPath implementation within Pathling supports the following types of literal expressions:
The Boolean type represents the logical Boolean values
String literals are surrounded by single-quotes and may use
\-escapes to escape quotes and represent Unicode characters:
- Unicode characters may be escaped using \u followed by four hex digits.
- Additional escapes are those supported in JSON:
\f(form feed -
\r(carriage return -
Unicode is supported in both string literals and delimited identifiers.
'test string' 'urn:oid:184.108.40.206.7.8' 'M\u00fcller'
The Integer type represents whole numbers.
The Decimal type represents real values.
The Date type represents date and partial date values, without a time component.
The Date literal is a subset of ISO 8601. It uses the
YYYY-MM-DD format, though month and day parts are optional.
@2014-01-25 @2014-01 @2014
The Time type represents time-of-day and partial time-of-day values.
The Time literal uses a subset of ISO 8601:
- A time begins with a
- It uses the
Thh:mm:ss.ffff±hh:mmformat, though minute, second, millisecond parts are optional
- Timezone is optional, but if present the notation
±hh:mmis used (so must include both minutes and hours)
Zis allowed as a synonym for the zero (+00:00) UTC offset.
@T07:30:14.559-07:00 @T14:30:14.559Z @T14:30 @T14
The Coding literal can take two forms:
Not all code systems require the use of a version to unambiguously specify a code - see Versioning Code Systems.
Codingliteral is not within the FHIRPath specification, and is currently unique to the Pathling implementation.