From dbfb2ab0e4e15d7503464aabb3971a38d8bde0e1 Mon Sep 17 00:00:00 2001
From: John Kerl <kerl.john.r@gmail.com>
Date: Tue, 22 Sep 2020 17:24:48 -0400
Subject: [PATCH] bulk label

---
 go/src/miller/mappers/label.go          | 10 +--------
 go/src/miller/types/mlrmap_accessors.go | 30 +++++++++++++++++++++++++
 go/todo.txt                             |  3 +--
 go/u/try-verbs.out                      | 20 ++++++++---------
 4 files changed, 42 insertions(+), 21 deletions(-)

diff --git a/go/src/miller/mappers/label.go b/go/src/miller/mappers/label.go
index 813ff9515..56701a4f1 100644
--- a/go/src/miller/mappers/label.go
+++ b/go/src/miller/mappers/label.go
@@ -109,15 +109,7 @@ func (this *MapperLabel) Map(
 ) {
 	inrec := inrecAndContext.Record
 	if inrec != nil { // not end of record stream
-
-		oldNames := inrec.GetKeys()
-		numOld := len(oldNames)
-		numNew := len(this.newNames)
-		numToRename := lib.IntMin2(numOld, numNew)
-
-		for i := 0; i < numToRename; i++ {
-			inrec.Rename(&oldNames[i], &this.newNames[i])
-		}
+		inrec.Label(this.newNames)
 	}
 	outputChannel <- inrecAndContext // end-of-stream marker
 }
diff --git a/go/src/miller/types/mlrmap_accessors.go b/go/src/miller/types/mlrmap_accessors.go
index 4af5b47f6..4cfb4dcd2 100644
--- a/go/src/miller/types/mlrmap_accessors.go
+++ b/go/src/miller/types/mlrmap_accessors.go
@@ -317,6 +317,36 @@ func (this *Mlrmap) Rename(oldKey *string, newKey *string) bool {
 	return true
 }
 
+// ----------------------------------------------------------------
+func (this *Mlrmap) Label(newNames []string) {
+	that := NewMlrmapAsRecord()
+
+	i := 0
+	numNewNames := len(newNames)
+	for {
+		if i >= numNewNames {
+			break
+		}
+		pe := this.pop()
+		if pe == nil {
+			break
+		}
+		// Old record will be GC'ed: just move pointers
+		that.PutReference(&newNames[i], pe.Value)
+		i++
+	}
+
+	for {
+		pe := this.pop()
+		if pe == nil {
+			break
+		}
+		that.PutReference(pe.Key, pe.Value)
+	}
+
+	*this = *that
+}
+
 // ================================================================
 // PRIVATE METHODS
 
diff --git a/go/todo.txt b/go/todo.txt
index e54acc0cd..4669f9e3c 100644
--- a/go/todo.txt
+++ b/go/todo.txt
@@ -17,8 +17,6 @@ TOP OF LIST:
     - default to absent (no hoisting)
     - no scope-walks needed for for-loops
 
-* rename: bulk-edit for b,i,x vs x,i,b cases
-
 ! filter
   > bare-boolean LR-1 conflicts wut
     ? erase BNF distinction between BaseLvalue and MlrvalOrFunction
@@ -164,3 +162,4 @@ NITS/NON-IMMEDIATE:
 * mlrdoc: there should have always been a >>> and >>>=, and now there are
 ! systime printing out in scientific notation :(
 ! head early-out -- cite the relevant issue & fix the right way ...
+* relnotes: label b,i,x vs x,i,b change
diff --git a/go/u/try-verbs.out b/go/u/try-verbs.out
index 196fc347b..8e4858c0e 100644
--- a/go/u/try-verbs.out
+++ b/go/u/try-verbs.out
@@ -259,19 +259,19 @@ eks wye 4 0.38139939387114097 0.13418874328430463
 
 ----------------------------------------------------------------
 mlr --opprint label b,i,x u/s.dkvp
-x   y
-pan 0.7268028627434533
-eks 0.5221511083334797
-wye 0.33831852551664776
-eks 0.13418874328430463
+b   i   x                   y
+pan pan 0.3467901443380824  0.7268028627434533
+eks pan 0.7586799647899636  0.5221511083334797
+wye wye 0.20460330576630303 0.33831852551664776
+eks wye 0.38139939387114097 0.13418874328430463
 
 ----------------------------------------------------------------
 mlr --opprint label x,i,b u/s.dkvp
-b   x   y
-pan pan 0.7268028627434533
-pan eks 0.5221511083334797
-wye wye 0.33831852551664776
-wye eks 0.13418874328430463
+x                   i   b y
+0.3467901443380824  pan 1 0.7268028627434533
+0.7586799647899636  pan 2 0.5221511083334797
+0.20460330576630303 wye 3 0.33831852551664776
+0.38139939387114097 wye 4 0.13418874328430463
 
 ----------------------------------------------------------------
 mlr --opprint --from u/s.dkvp sort -f nonesuch