[det]unicode_restriction_level(+Text,
-Level:atom)Classify Text under UTS #39 §5.2 at the most restrictive
level for which it qualifies. Level is one of:
ascii_only — every code point in U+0020..U+007E and
Allowed.single_script — augmented resolved-script-set
non-empty and every code point Allowed.highly_restrictive — covered by Latin plus one of Hanb,
Jpan or Kore (UTS #39 §5.1 augmented
profiles).moderately_restrictive — covered by Latin plus a
single non-Latin Recommended script (Cyrl or Grek).minimally_restrictive — every code point has
Identifier_Type in {recommended, inclusion}.unrestricted — otherwise. A linter that walks source
clauses and reports atoms with the confusability issues above is
registered in library(check) itself (predicate list_confusable_identifiers/0);
see the
library(check) documentation for details.