Fixed variable operator to work like jq

pkg/yqlib/doc/operators/multiply-merge.md

@@ -329,7 +329,16 @@ idPath=".a"  originalPath=".myArray"  otherPath=".newArray" yq eval-all '
 ```
 will output
 ```yaml
-myArray: []
+myArray:
+  - a: apple
+    b: appleB2
+  - a: kiwi
+    b: kiwiB
+  - a: banana
+    b: bananaB
+    c: bananaC
+  - a: dingo
+    c: dingoC
 something: else
 ```
 

pkg/yqlib/operator_alternative_test.go

@@ -16,7 +16,7 @@ var alternativeOperatorScenarios = []expressionScenario{
 	},
 	{
 		skipDoc:    true,
-		expression: `(.b // "hello") as $x`,
+		expression: `(.b // "hello") as $x | .`,
 		document:   `a: bridge`,
 		expected: []string{
 			"D0, P[], (doc)::a: bridge\n",

pkg/yqlib/operator_booleans_test.go

@@ -102,7 +102,7 @@ var booleanOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
 		document:   `[{pet: cat}]`,
-		expression: `any_c(.name == "harry") as $c`,
+		expression: `any_c(.name == "harry") as $c | .`,
 		expected: []string{
 			"D0, P[], (doc)::[{pet: cat}]\n",
 		},
@@ -110,9 +110,17 @@ var booleanOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
 		document:   `[{pet: cat}]`,
-		expression: `all_c(.name == "harry") as $c`,
+		expression: `any_c(.name == "harry") as $c | $c`,
 		expected: []string{
-			"D0, P[], (doc)::[{pet: cat}]\n",
+			"D0, P[], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `[{pet: cat}]`,
+		expression: `all_c(.name == "harry") as $c | $c`,
+		expected: []string{
+			"D0, P[], (!!bool)::false\n",
 		},
 	},
 	{
@@ -185,7 +193,7 @@ var booleanOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
 		document:   `{}`,
-		expression: `(.a.b or .c) as $x`,
+		expression: `(.a.b or .c) as $x | .`,
 		expected: []string{
 			"D0, P[], (doc)::{}\n",
 		},
@@ -193,7 +201,7 @@ var booleanOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
 		document:   `{}`,
-		expression: `(.a.b and .c) as $x`,
+		expression: `(.a.b and .c) as $x | .`,
 		expected: []string{
 			"D0, P[], (doc)::{}\n",
 		},

pkg/yqlib/operator_equals_test.go

@@ -47,7 +47,7 @@ var equalsOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
 		document:   "{}",
-		expression: "(.a == .b) as $x",
+		expression: "(.a == .b) as $x | .",
 		expected: []string{
 			"D0, P[], (doc)::{}\n",
 		},
@@ -63,7 +63,7 @@ var equalsOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
 		document:   "{}",
-		expression: "(.a != .b) as $x",
+		expression: "(.a != .b) as $x | .",
 		expected: []string{
 			"D0, P[], (doc)::{}\n",
 		},

pkg/yqlib/operator_has_test.go

@@ -16,7 +16,7 @@ var hasOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
 		document:   `a: hello`,
-		expression: `has(.b) as $c`,
+		expression: `has(.b) as $c | .`,
 		expected: []string{
 			"D0, P[], (doc)::a: hello\n",
 		},

pkg/yqlib/operator_subtract_test.go

@@ -8,7 +8,7 @@ var subtractOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
 		document:   `{}`,
-		expression: "(.a - .b) as $x",
+		expression: "(.a - .b) as $x | .",
 		expected: []string{
 			"D0, P[], (doc)::{}\n",
 		},

pkg/yqlib/operator_traverse_path_test.go

@@ -151,7 +151,7 @@ var traversePathOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
 		document:   `c: dog`,
-		expression: `.[.a.b] as $x`,
+		expression: `.[.a.b] as $x | .`,
 		expected: []string{
 			"D0, P[], (doc)::c: dog\n",
 		},

pkg/yqlib/operator_union_test.go

@@ -8,7 +8,7 @@ var unionOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
 		document:   "{}",
-		expression: `(.a, .b.c) as $x`,
+		expression: `(.a, .b.c) as $x | .`,
 		expected: []string{
 			"D0, P[], (doc)::{}\n",
 		},

pkg/yqlib/operator_variables.go

@@ -28,6 +28,17 @@ func useWithPipe(d *dataTreeNavigator, context Context, originalExp *ExpressionN
 func variableLoop(d *dataTreeNavigator, context Context, originalExp *ExpressionNode) (Context, error) {
 	log.Debug("variable loop!")
 	results := list.New()
+	var evaluateAllTogether = true
+	for matchEl := context.MatchingNodes.Front(); matchEl != nil; matchEl = matchEl.Next() {
+		evaluateAllTogether = evaluateAllTogether && matchEl.Value.(*CandidateNode).EvaluateTogether
+		if !evaluateAllTogether {
+			break
+		}
+	}
+	if evaluateAllTogether {
+		return variableLoopSingleChild(d, context, originalExp)
+	}
+
 	for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
 		result, err := variableLoopSingleChild(d, context.SingleChildContext(el.Value.(*CandidateNode)), originalExp)
 		if err != nil {
@@ -56,17 +67,17 @@ func variableLoopSingleChild(d *dataTreeNavigator, context Context, originalExp
 
 	// now we loop over lhs, set variable to each result and calculate originalExp.Rhs
 	for el := lhs.MatchingNodes.Front(); el != nil; el = el.Next() {
+		log.Debug("PROCESSING VARIABLE: ", NodeToString(el.Value.(*CandidateNode)))
 		var variableValue = list.New()
 		if prefs.IsReference {
 			variableValue.PushBack(el.Value)
 		} else {
-			copy, err := el.Value.(*CandidateNode).Copy()
+			candidateCopy, err := el.Value.(*CandidateNode).Copy()
 			if err != nil {
 				return Context{}, err
 			}
-			variableValue.PushBack(copy)
+			variableValue.PushBack(candidateCopy)
 		}
-		log.Debug("PROCESSING VARIABLE: ", NodeToString(el.Value.(*CandidateNode)))
 		newContext := context.ChildContext(context.MatchingNodes)
 		newContext.SetVariable(variableName, variableValue)