Replace append with walk.ConcatData in many places to fix bug to do with semantics of append

When doing append, be very careful as it does make changes in place to the underlying array of the slice which may affect other slices

1 files changed, 2 insertions, 2 deletions

diff --git a/subex/main.go b/subex/main.go
index e53a3c6..138de9a 100644
--- a/subex/main.go
+++ b/subex/main.go
@@ -66,7 +66,7 @@ type SubexBranch struct {
 func (pair SubexBranch) eat(char walk.Datum) []SubexBranch {
 	states := pair.state.eat(pair.store, char)
 	for i := range states {
-		states[i].output = append(pair.output, states[i].output...)
+		states[i].output = walk.ConcatData(pair.output, states[i].output)
 	}
 	return states
 }
@@ -110,7 +110,7 @@ func RunTransducer(transducer SubexState, input <-chan walk.Datum) (output []wal
 	for _, state := range states {
 		outputEnds := state.accepting()
 		for _, outputEnd := range outputEnds {
-			return append(state.output, outputEnd...), false
+			return walk.ConcatData(state.output, outputEnd), false
 		}
 	}
 	return nil, true