From 1941bb66a5aa88cf245548b57b25fb84fe962898 Mon Sep 17 00:00:00 2001
From: Mike Farah <mikefarah@gmail.com>
Date: Mon, 18 Jan 2021 10:15:31 +1100
Subject: [PATCH] wip

---
 pkg/yqlib/candidate_node.go         |  3 ++
 pkg/yqlib/operator_multiply.go      | 55 +++++++++++++++++------------
 pkg/yqlib/operator_multiply_test.go |  4 ++-
 pkg/yqlib/utils.go                  |  9 ++---
 4 files changed, 44 insertions(+), 27 deletions(-)

diff --git a/pkg/yqlib/candidate_node.go b/pkg/yqlib/candidate_node.go
index 0fd2fe59..f3801f63 100644
--- a/pkg/yqlib/candidate_node.go
+++ b/pkg/yqlib/candidate_node.go
@@ -15,6 +15,9 @@ type CandidateNode struct {
 	Document  uint          // the document index of this node
 	Filename  string
 	FileIndex int
+	// when performing op against all nodes given, this will treat all the nodes as one
+	// (e.g. top level cross document merge). This property does not propegate to child nodes.
+	EvaluateTogether bool
 }
 
 func (n *CandidateNode) GetKey() string {
diff --git a/pkg/yqlib/operator_multiply.go b/pkg/yqlib/operator_multiply.go
index 4d98246c..98919632 100644
--- a/pkg/yqlib/operator_multiply.go
+++ b/pkg/yqlib/operator_multiply.go
@@ -10,38 +10,49 @@ import (
 
 type crossFunctionCalculation func(d *dataTreeNavigator, lhs *CandidateNode, rhs *CandidateNode) (*CandidateNode, error)
 
-func crossFunction(d *dataTreeNavigator, matchingNodes *list.List, expressionNode *ExpressionNode, calculation crossFunctionCalculation) (*list.List, error) {
+func doCrossFunc(d *dataTreeNavigator, contextList *list.List, expressionNode *ExpressionNode, calculation crossFunctionCalculation) (*list.List, error) {
+	var results = list.New()
+	lhs, err := d.GetMatchingNodes(contextList, expressionNode.Lhs)
+	if err != nil {
+		return nil, err
+	}
+	log.Debugf("crossFunction LHS len: %v", lhs.Len())
 
+	rhs, err := d.GetMatchingNodes(contextList, expressionNode.Rhs)
+
+	if err != nil {
+		return nil, err
+	}
+
+	for el := lhs.Front(); el != nil; el = el.Next() {
+		lhsCandidate := el.Value.(*CandidateNode)
+
+		for rightEl := rhs.Front(); rightEl != nil; rightEl = rightEl.Next() {
+			log.Debugf("Applying calc")
+			rhsCandidate := rightEl.Value.(*CandidateNode)
+			resultCandidate, err := calculation(d, lhsCandidate, rhsCandidate)
+			if err != nil {
+				return nil, err
+			}
+			results.PushBack(resultCandidate)
+		}
+
+	}
+	return results, nil
+}
+
+func crossFunction(d *dataTreeNavigator, matchingNodes *list.List, expressionNode *ExpressionNode, calculation crossFunctionCalculation) (*list.List, error) {
 	var results = list.New()
 	for matchEl := matchingNodes.Front(); matchEl != nil; matchEl = matchEl.Next() {
 		contextList := nodeToMap(matchEl.Value.(*CandidateNode))
 
-		lhs, err := d.GetMatchingNodes(contextList, expressionNode.Lhs)
-		if err != nil {
-			return nil, err
-		}
-		log.Debugf("crossFunction LHS len: %v", lhs.Len())
-
-		rhs, err := d.GetMatchingNodes(contextList, expressionNode.Rhs)
+		innerResults, err := doCrossFunc(d, contextList, expressionNode, calculation)
 
 		if err != nil {
 			return nil, err
 		}
 
-		for el := lhs.Front(); el != nil; el = el.Next() {
-			lhsCandidate := el.Value.(*CandidateNode)
-
-			for rightEl := rhs.Front(); rightEl != nil; rightEl = rightEl.Next() {
-				log.Debugf("Applying calc")
-				rhsCandidate := rightEl.Value.(*CandidateNode)
-				resultCandidate, err := calculation(d, lhsCandidate, rhsCandidate)
-				if err != nil {
-					return nil, err
-				}
-				results.PushBack(resultCandidate)
-			}
-
-		}
+		results.PushBackList(innerResults)
 
 	}
 
diff --git a/pkg/yqlib/operator_multiply_test.go b/pkg/yqlib/operator_multiply_test.go
index 8635686d..09b466d8 100644
--- a/pkg/yqlib/operator_multiply_test.go
+++ b/pkg/yqlib/operator_multiply_test.go
@@ -12,6 +12,8 @@ import (
 // d0a d1a d0b d1b
 // run it for (d0a d1a) x (d0b d1b) - noting that we dont do (d0a x d1a) nor (d0b d1b)
 // I think this will work for eval-all correctly then..
+
+//alternative, like jq, eval-all puts all docs in an single array.
 var multiplyOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
@@ -25,7 +27,7 @@ var multiplyOperatorScenarios = []expressionScenario{
 		skipDoc:    true,
 		document:   `a: {also: [1]}`,
 		document2:  `b: {also: me}`,
-		expression: `. * {"a" : .b}`,
+		expression: `.a * .b`,
 		expected: []string{
 			"D0, P[], (!!map)::{a: {also: me}, b: {also: me}}\n",
 		},
diff --git a/pkg/yqlib/utils.go b/pkg/yqlib/utils.go
index 3e8084bc..dd93d248 100644
--- a/pkg/yqlib/utils.go
+++ b/pkg/yqlib/utils.go
@@ -36,10 +36,11 @@ func readDocuments(reader io.Reader, filename string, fileIndex int) (*list.List
 			return nil, errorReading
 		}
 		candidateNode := &CandidateNode{
-			Document:  currentIndex,
-			Filename:  filename,
-			Node:      &dataBucket,
-			FileIndex: fileIndex,
+			Document:         currentIndex,
+			Filename:         filename,
+			Node:             &dataBucket,
+			FileIndex:        fileIndex,
+			EvaluateTogether: true,
 		}
 
 		inputList.PushBack(candidateNode)