iterating

pkg/transformers/bootstrap.go

@@ -97,7 +97,7 @@ type TransformerBootstrap struct {
 
 func NewTransformerBootstrap(nout int64) (*TransformerBootstrap, error) {
 	tr := &TransformerBootstrap{
-		recordsAndContexts: list.New(),
+		recordsAndContexts: make([]*types.RecordAndContext, 100), // XXX recordsPerBatch
 		nout:               nout,
 	}
 	return tr, nil
@@ -114,7 +114,7 @@ func (tr *TransformerBootstrap) Transform(
 	HandleDefaultDownstreamDone(inputDownstreamDoneChannel, outputDownstreamDoneChannel)
 	// Not end of input stream: retain the record, and emit nothing until end of stream.
 	if !inrecAndContext.EndOfStream {
-		tr.recordsAndContexts.PushBack(inrecAndContext)
+		tr.recordsAndContexts = append(tr.recordsAndContexts, inrecAndContext)
 		return
 	}
 
@@ -142,7 +142,7 @@ func (tr *TransformerBootstrap) Transform(
 	// For that reason, this transformer must copy all output.
 
 	// TODO: Go list Len() maxes at 2^31. We should track this ourselves in an int.
-	nin := int64(tr.recordsAndContexts.Len())
+	nin := int64(len(tr.recordsAndContexts))
 	nout := tr.nout
 	if nout == -1 {
 		nout = nin
@@ -157,12 +157,12 @@ func (tr *TransformerBootstrap) Transform(
 	// Make an array of pointers into the input list.
 	recordArray := make([]*types.RecordAndContext, nin)
 	for i := int64(0); i < nin; i++ {
-		head := tr.recordsAndContexts.Front()
+		head := tr.recordsAndContexts[0]
 		if head == nil {
 			break
 		}
-		recordArray[i] = head.Value.(*types.RecordAndContext)
+		recordArray[i] = head
-		tr.recordsAndContexts.Remove(head)
+		tr.recordsAndContexts = tr.recordsAndContexts[1:]
 	}
 
 	// Do the sample-with-replacment, reading from random indices in the input
@@ -171,7 +171,7 @@ func (tr *TransformerBootstrap) Transform(
 		index := lib.RandRange(0, nin)
 		recordAndContext := recordArray[index]
 		// Already emitted once; copy
-		outputRecordsAndContexts.PushBack(recordAndContext.Copy())
+		outputRecordsAndContexts = append(outputRecordsAndContexts, recordAndContext.Copy())
 	}
 
 	// Emit the stream-terminating null record

pkg/transformers/case.go

@@ -229,7 +229,10 @@ func (tr *TransformerCase) transformValuesOnly(
 			}
 		}
 	}
-	outputRecordsAndContexts.PushBack(types.NewRecordAndContext(inrec, &inrecAndContext.Context))
+	outputRecordsAndContexts = append(
+		outputRecordsAndContexts,
+		types.NewRecordAndContext(inrec, &inrecAndContext.Context),
+	)
 }
 
 func (tr *TransformerCase) transformKeysAndValues(

pkg/transformers/count_similar.go

@@ -157,7 +157,7 @@ func (tr *TransformerCountSimilar) Transform(
 				recordAndContext := inner.Value.(*types.RecordAndContext)
 				recordAndContext.Record.PutCopy(tr.counterFieldName, mgroupSize)
 
-				outputRecordsAndContexts.PushBack(recordAndContext)
+				outputRecordsAndContexts = append(outputRecordsAndContexts, recordAndContext)
 			}
 		}
 

pkg/transformers/fraction.go

@@ -292,7 +292,10 @@ func (tr *TransformerFraction) Transform(
 				}
 			}
 
-			outputRecordsAndContexts.PushBack(types.NewRecordAndContext(outrec, &endOfStreamContext))
+			outputRecordsAndContexts = append(
+				outputRecordsAndContexts,
+				types.NewRecordAndContext(outrec, &endOfStreamContext),
+			)
 		}
 		outputRecordsAndContexts = append(outputRecordsAndContexts, inrecAndContext) // end-of-stream marker
 	}

pkg/transformers/group_by.go

@@ -136,9 +136,9 @@ func (tr *TransformerGroupBy) Transform(
 
 	} else {
 		for outer := tr.recordListsByGroup.Head; outer != nil; outer = outer.Next {
-			recordListForGroup := outer.Value.(*list.List)
+			recordListForGroup := outer.Value.([]*types.RecordAndContext)
-			for inner := recordListForGroup.Front(); inner != nil; inner = inner.Next() {
+			for _, record := range recordListForGroup {
-				outputRecordsAndContexts.PushBack(inner.Value.(*types.RecordAndContext))
+				outputRecordsAndContexts = append(outputRecordsAndContexts, record)
 			}
 		}
 		outputRecordsAndContexts = append(outputRecordsAndContexts, inrecAndContext) // end-of-stream marker

pkg/transformers/group_like.go

@@ -115,9 +115,9 @@ func (tr *TransformerGroupLike) Transform(
 
 	} else {
 		for outer := tr.recordListsByGroup.Head; outer != nil; outer = outer.Next {
-			recordListForGroup := outer.Value.(*list.List)
+			recordListForGroup := outer.Value.([]*types.RecordAndContext)
-			for inner := recordListForGroup.Front(); inner != nil; inner = inner.Next() {
+			for _, record := range recordListForGroup {
-				outputRecordsAndContexts.PushBack(inner.Value.(*types.RecordAndContext))
+				outputRecordsAndContexts = append(outputRecordsAndContexts, record)
 			}
 		}
 		outputRecordsAndContexts = append(outputRecordsAndContexts, inrecAndContext) // end-of-stream marker

pkg/transformers/histogram.go

@@ -275,7 +275,10 @@ func (tr *TransformerHistogram) emitNonAuto(
 			)
 		}
 
-		outputRecordsAndContexts.PushBack(types.NewRecordAndContext(outrec, endOfStreamContext))
+		outputRecordsAndContexts = append(
+			outputRecordsAndContexts,
+			types.NewRecordAndContext(outrec, endOfStreamContext),
+		)
 	}
 }
 
@@ -381,6 +384,9 @@ func (tr *TransformerHistogram) emitAuto(
 			)
 		}
 
-		outputRecordsAndContexts.PushBack(types.NewRecordAndContext(outrec, endOfStreamContext))
+		outputRecordsAndContexts = append(
+			outputRecordsAndContexts,
+			types.NewRecordAndContext(outrec, endOfStreamContext),
+		)
 	}
 }

pkg/transformers/utils/join_bucket.go

@@ -5,15 +5,14 @@
 package utils
 
 import (
-	"container/list"
-
 	"github.com/johnkerl/miller/v6/pkg/mlrval"
+	"github.com/johnkerl/miller/v6/pkg/types"
 )
 
 // ----------------------------------------------------------------
 type JoinBucket struct {
 	leftFieldValues    []*mlrval.Mlrval
-	RecordsAndContexts *list.List
+	RecordsAndContexts []*types.RecordAndContext
 	WasPaired          bool
 }
 
@@ -22,7 +21,7 @@ func NewJoinBucket(
 ) *JoinBucket {
 	return &JoinBucket{
 		leftFieldValues:    leftFieldValues,
-		RecordsAndContexts: list.New(),
+		RecordsAndContexts: make([]*types.RecordAndContext, 0),
 		WasPaired:          false,
 	}
 }

pkg/transformers/utils/join_bucket_keeper.go

@@ -289,7 +289,7 @@ func (keeper *JoinBucketKeeper) FindJoinBucket(
 				}
 
 				// TODO: privatize more
-				if keeper.JoinBucket.RecordsAndContexts.Len() > 0 {
+				if len(keeper.JoinBucket.RecordsAndContexts) > 0 {
 					cmp := compareLexically(
 						keeper.JoinBucket.leftFieldValues,
 						rightFieldValues,