TraceContext.Entries.unique: def of bend-trace-context@0.2.0.0
Import: import bend-trace-context@0.2.0.0/trace_context.bend as TraceContext
Lines 1913-1921 of bend-trace-context@0.2.0.0/trace_context.bend: https://jend.leeeet.dev/read.txt?path=bend-trace-context@0.2.0.0/trace_context.bend&start_line=1913&end_line=1921

import Base

# No entry repeats the key of an entry before it; `seen` holds the entries
# already passed. This is the order in which the reading machine checks keys.
def Entries.unique(entries: List<&2, StateEntry>, +seen: List<&2, StateEntry>) -> Bool:
  match entries:
    case Nil{}:
      True{}
    case Con{+entry, rest}:
      Bool.and(Bool.not(Entries.has_key(seen, StateEntry.key_text(entry))),
        Entries.unique(rest, List.append(&2, StateEntry, seen, Con{entry, Nil{}})))

Uses (8):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.not
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.append
  https://jend.leeeet.dev/definition.txt?path=bend-trace-context@0.2.0.0/trace_context.bend&name=Entries.has_key
  https://jend.leeeet.dev/definition.txt?path=bend-trace-context@0.2.0.0/trace_context.bend&name=StateEntry
  https://jend.leeeet.dev/definition.txt?path=bend-trace-context@0.2.0.0/trace_context.bend&name=StateEntry.key_text