Document new kgtk_literal built-in predicate.
@@ -1569,6 +1569,7 @@ TO DO
| Function | Description |
|-----------------------|--------------------------------------------------------------------------------------------|
+| kgtk_literal(x) | Return True if 'x' is any KGTK literal. This assumes valid literals and only tests the first character (except for booleans). |
| kgtk_regex(x, regex) | Regex matcher that implements the Cypher `=~` semantics which must match the whole string. |
| kgtk_null_to_empty(x) | If `x` is NULL map it onto the empty string, otherwise return `x` unmodified. |
| kgtk_empty_to_null(x) | If `x` is the empty string, map it onto NULL, otherwise return `x` unmodified. |
