Concat.appended: def of bolt@1.27.0.0
Import: import bolt@1.27.0.0/src/rules/suspicious/concat.bend as Concat
Lines 50-54 of bolt@1.27.0.0/src/rules/suspicious/concat.bend: https://jend.leeeet.dev/read.txt?path=bolt@1.27.0.0/src/rules/suspicious/concat.bend&start_line=50&end_line=54

import 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
import bolt@1.27.0.0/src/rules/calls.bend as Calls

# the list a call appends onto: List.append's first list, String.append's first
def appended(+tt: String, as: List<&2, Tree.Node>) -> Maybe<&2, Lex.Tok>:
  +list = String.eq(tt, "List.append")
  +str = String.eq(tt, "String.append")
  Bool.pick(Maybe<&2, Lex.Tok>, Bool.or(list, str), lone(Calls.arg(as, Bool.pick(Nat, list, 2n, 0n))), None{})

Uses (11):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.or
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.pick
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String.eq
  https://jend.leeeet.dev/definition.txt?path=bolt@1.27.0.0/src/rules/calls.bend&name=arg
  https://jend.leeeet.dev/definition.txt?path=bolt@1.27.0.0/src/rules/suspicious/concat.bend&name=lone
  https://jend.leeeet.dev/definition.txt?path=bolt@1.27.0.0/src/syntax/lex.bend&name=Tok
  https://jend.leeeet.dev/definition.txt?path=bolt@1.27.0.0/src/syntax/tree.bend&name=Node