+! Copyright (C) 2022 Doug Coleman.
+! See http://factorcode.org/license.txt for BSD license.
+USING: accessors assocs biassocs fonts kernel math.combinatorics
+ranges sequences sequences.extras strings ui.text unicode.flags ;
+IN: unicode.flags.images
+
+MEMO: valid-flags ( -- flags )
+ CHAR: a CHAR: z [a..b] 2 <k-permutations>
+ [ >string unicode>flag ]
+ [ monospace-font swap string>image drop dim>> first2 = ] map-filter ;
+
+: valid-flag-names ( -- seq )
+ valid-flags [ flag>unicode ] map ;
+
+: valid-flag-biassoc ( -- biassoc )
+ valid-flags valid-flag-names zip >biassoc ;