def seen
import bolt@1.27.0.0/src/rules/suspicious/concat.bend as Concatimport Base
import bolt@1.27.0.0/src/syntax/lex.bend as Lex
import bolt@1.27.0.0/src/syntax/tree.bend as Tree
118# the name an argument appends onto, in place or through a let
119def seen(+aa: Tree.Node, +lets: List<&2, Let>) -> Maybe<&2, Lex.Tok>:
120 either(onto(aa), via(aa, lets))