Traverse Array Operator

pkg/yqlib/doc/Assign.md

@@ -112,7 +112,7 @@ a:
 ```
 then
 ```bash
-yq eval '(.a.[] | select(. == "apple")) = "frog"' sample.yml
+yq eval '(.a[] | select(. == "apple")) = "frog"' sample.yml
 ```
 will output
 ```yaml

pkg/yqlib/doc/Traverse.md

@@ -366,3 +366,21 @@ bar_thing
 foobarList_c
 ```
 
+## Select multiple indices
+Given a sample.yml file of:
+```yaml
+a:
+  - a
+  - b
+  - c
+```
+then
+```bash
+yq eval '.a[0, 2]' sample.yml
+```
+will output
+```yaml
+a
+c
+```
+

pkg/yqlib/lib.go

@@ -65,6 +65,7 @@ var SortKeys = &OperationType{Type: "SORT_KEYS", NumArgs: 1, Precedence: 50, Han
 
 var CollectObject = &OperationType{Type: "COLLECT_OBJECT", NumArgs: 0, Precedence: 50, Handler: CollectObjectOperator}
 var TraversePath = &OperationType{Type: "TRAVERSE_PATH", NumArgs: 0, Precedence: 50, Handler: TraversePathOperator}
+var TraverseArray = &OperationType{Type: "TRAVERSE_ARRAY", NumArgs: 1, Precedence: 50, Handler: TraverseArrayOperator}
 
 var DocumentFilter = &OperationType{Type: "DOCUMENT_FILTER", NumArgs: 0, Precedence: 50, Handler: TraversePathOperator}
 var SelfReference = &OperationType{Type: "SELF", NumArgs: 0, Precedence: 50, Handler: SelfOperator}

pkg/yqlib/operator_assign_test.go

@@ -80,6 +80,14 @@ var assignOperatorScenarios = []expressionScenario{
 	{
 		description: "Update selected results",
 		document:    `{a: {b: apple, c: cactus}}`,
+		expression:  `(.a[] | select(. == "apple")) = "frog"`,
+		expected: []string{
+			"D0, P[], (doc)::{a: {b: frog, c: cactus}}\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: {b: apple, c: cactus}}`,
 		expression: `(.a.[] | select(. == "apple")) = "frog"`,
 		expected: []string{
 			"D0, P[], (doc)::{a: {b: frog, c: cactus}}\n",

pkg/yqlib/operator_traverse_path.go

@@ -1,9 +1,9 @@
 package yqlib
 
 import (
-	"fmt"
-
 	"container/list"
+	"fmt"
+	"strconv"
 
 	"github.com/elliotchance/orderedmap"
 	yaml "gopkg.in/yaml.v3"
@@ -14,10 +14,7 @@ type TraversePreferences struct {
 }
 
 func Splat(d *dataTreeNavigator, matches *list.List) (*list.List, error) {
-	preferences := &TraversePreferences{DontFollowAlias: true}
+	return traverseNodesWithArrayIndices(matches, make([]*yaml.Node, 0), false)
-	splatOperation := &Operation{OperationType: TraversePath, Value: "[]", Preferences: preferences}
-	splatTreeNode := &PathTreeNode{Operation: splatOperation}
-	return TraversePathOperator(d, matches, splatTreeNode)
 }
 
 func TraversePathOperator(d *dataTreeNavigator, matchMap *list.List, pathNode *PathTreeNode) (*list.List, error) {
@@ -56,7 +53,12 @@ func traverse(d *dataTreeNavigator, matchingNode *CandidateNode, operation *Oper
 	switch value.Kind {
 	case yaml.MappingNode:
 		log.Debug("its a map with %v entries", len(value.Content)/2)
-		return traverseMap(matchingNode, operation)
+		followAlias := true
+
+		if operation.Preferences != nil {
+			followAlias = !operation.Preferences.(*TraversePreferences).DontFollowAlias
+		}
+		return traverseMap(matchingNode, operation.StringValue, followAlias, false)
 
 	case yaml.SequenceNode:
 		log.Debug("its a sequence of %v things!", len(value.Content))
@@ -70,19 +72,143 @@ func traverse(d *dataTreeNavigator, matchingNode *CandidateNode, operation *Oper
 		log.Debug("digging into doc node")
 		return traverse(d, &CandidateNode{
 			Node:      matchingNode.Node.Content[0],
+			Filename:  matchingNode.Filename,
+			FileIndex: matchingNode.FileIndex,
 			Document:  matchingNode.Document}, operation)
 	default:
 		return list.New(), nil
 	}
 }
 
-func keyMatches(key *yaml.Node, pathNode *Operation) bool {
+func TraverseArrayOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
-	return pathNode.Value == "[]" || Match(key.Value, pathNode.StringValue)
+	// rhs is a collect expression that will yield indexes to retreive of the arrays
+
+	rhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Rhs)
+	if err != nil {
+		return nil, err
+	}
+
+	var indicesToTraverse = rhs.Front().Value.(*CandidateNode).Node.Content
+
+	return traverseNodesWithArrayIndices(matchingNodes, indicesToTraverse, true)
 }
 
-func traverseMap(matchingNode *CandidateNode, operation *Operation) (*list.List, error) {
+func traverseNodesWithArrayIndices(matchingNodes *list.List, indicesToTraverse []*yaml.Node, followAlias bool) (*list.List, error) {
+	var matchingNodeMap = list.New()
+	for el := matchingNodes.Front(); el != nil; el = el.Next() {
+		candidate := el.Value.(*CandidateNode)
+		newNodes, err := traverseArrayIndices(candidate, indicesToTraverse, followAlias)
+		if err != nil {
+			return nil, err
+		}
+		matchingNodeMap.PushBackList(newNodes)
+	}
+
+	return matchingNodeMap, nil
+}
+
+func traverseArrayIndices(matchingNode *CandidateNode, indicesToTraverse []*yaml.Node, followAlias bool) (*list.List, error) { // call this if doc / alias like the other traverse
+	node := matchingNode.Node
+	if node.Tag == "!!null" {
+		log.Debugf("OperatorArrayTraverse got a null - turning it into an empty array")
+		// auto vivification, make it into an empty array
+		node.Tag = ""
+		node.Kind = yaml.SequenceNode
+	}
+
+	if node.Kind == yaml.AliasNode {
+		matchingNode.Node = node.Alias
+		return traverseArrayIndices(matchingNode, indicesToTraverse, followAlias)
+	} else if node.Kind == yaml.SequenceNode {
+		return traverseArrayWithIndices(matchingNode, indicesToTraverse)
+	} else if node.Kind == yaml.MappingNode {
+		return traverseMapWithIndices(matchingNode, indicesToTraverse, followAlias)
+	} else if node.Kind == yaml.DocumentNode {
+		return traverseArrayIndices(&CandidateNode{
+			Node:      matchingNode.Node.Content[0],
+			Filename:  matchingNode.Filename,
+			FileIndex: matchingNode.FileIndex,
+			Document:  matchingNode.Document}, indicesToTraverse, followAlias)
+	}
+	log.Debugf("OperatorArrayTraverse skipping %v as its a %v", matchingNode, node.Tag)
+	return list.New(), nil
+}
+
+func traverseMapWithIndices(candidate *CandidateNode, indices []*yaml.Node, followAlias bool) (*list.List, error) {
+	if len(indices) == 0 {
+		return traverseMap(candidate, "", followAlias, true)
+	}
+
+	var matchingNodeMap = list.New()
+
+	for _, indexNode := range indices {
+		log.Debug("traverseMapWithIndices: %v", indexNode.Value)
+		newNodes, err := traverseMap(candidate, indexNode.Value, followAlias, false)
+		if err != nil {
+			return nil, err
+		}
+		matchingNodeMap.PushBackList(newNodes)
+	}
+
+	return matchingNodeMap, nil
+}
+
+func traverseArrayWithIndices(candidate *CandidateNode, indices []*yaml.Node) (*list.List, error) {
+	log.Debug("traverseArrayWithIndices")
+	var newMatches = list.New()
+	node := UnwrapDoc(candidate.Node)
+	if len(indices) == 0 {
+		log.Debug("splatting")
+		var index int64
+		for index = 0; index < int64(len(node.Content)); index = index + 1 {
+
+			newMatches.PushBack(&CandidateNode{
+				Document: candidate.Document,
+				Path:     candidate.CreateChildPath(index),
+				Node:     node.Content[index],
+			})
+		}
+		return newMatches, nil
+
+	}
+
+	for _, indexNode := range indices {
+		log.Debug("traverseArrayWithIndices: '%v'", indexNode.Value)
+		index, err := strconv.ParseInt(indexNode.Value, 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("Cannot index array with '%v' (%v)", indexNode.Value, err)
+		}
+		indexToUse := index
+		contentLength := int64(len(node.Content))
+		for contentLength <= index {
+			node.Content = append(node.Content, &yaml.Node{Tag: "!!null", Kind: yaml.ScalarNode, Value: "null"})
+			contentLength = int64(len(node.Content))
+		}
+
+		if indexToUse < 0 {
+			indexToUse = contentLength + indexToUse
+		}
+
+		if indexToUse < 0 {
+			return nil, fmt.Errorf("Index [%v] out of range, array size is %v", index, contentLength)
+		}
+
+		newMatches.PushBack(&CandidateNode{
+			Node:     node.Content[indexToUse],
+			Document: candidate.Document,
+			Path:     candidate.CreateChildPath(index),
+		})
+	}
+	return newMatches, nil
+}
+
+func keyMatches(key *yaml.Node, wantedKey string) bool {
+	return Match(key.Value, wantedKey)
+}
+
+func traverseMap(matchingNode *CandidateNode, key string, followAlias bool, splat bool) (*list.List, error) {
 	var newMatches = orderedmap.NewOrderedMap()
-	err := doTraverseMap(newMatches, matchingNode, operation)
+	err := doTraverseMap(newMatches, matchingNode, key, followAlias, splat)
 
 	if err != nil {
 		return nil, err
@@ -92,10 +218,10 @@ func traverseMap(matchingNode *CandidateNode, operation *Operation) (*list.List,
 		//no matches, create one automagically
 		valueNode := &yaml.Node{Tag: "!!null", Kind: yaml.ScalarNode, Value: "null"}
 		node := matchingNode.Node
-		node.Content = append(node.Content, &yaml.Node{Kind: yaml.ScalarNode, Value: operation.StringValue}, valueNode)
+		node.Content = append(node.Content, &yaml.Node{Kind: yaml.ScalarNode, Value: key}, valueNode)
 		candidateNode := &CandidateNode{
 			Node:     valueNode,
-			Path:     append(matchingNode.Path, operation.StringValue),
+			Path:     append(matchingNode.Path, key),
 			Document: matchingNode.Document,
 		}
 		newMatches.Set(candidateNode.GetKey(), candidateNode)
@@ -111,21 +237,14 @@ func traverseMap(matchingNode *CandidateNode, operation *Operation) (*list.List,
 	return results, nil
 }
 
-func doTraverseMap(newMatches *orderedmap.OrderedMap, candidate *CandidateNode, operation *Operation) error {
+func doTraverseMap(newMatches *orderedmap.OrderedMap, candidate *CandidateNode, wantedKey string, followAlias bool, splat bool) error {
 	// value.Content is a concatenated array of key, value,
 	// so keys are in the even indexes, values in odd.
 	// merge aliases are defined first, but we only want to traverse them
 	// if we don't find a match directly on this node first.
-	//TODO ALIASES, auto creation?
 
 	node := candidate.Node
 
-	followAlias := true
-
-	if operation.Preferences != nil {
-		followAlias = !operation.Preferences.(*TraversePreferences).DontFollowAlias
-	}
-
 	var contents = node.Content
 	for index := 0; index < len(contents); index = index + 2 {
 		key := contents[index]
@@ -135,11 +254,11 @@ func doTraverseMap(newMatches *orderedmap.OrderedMap, candidate *CandidateNode,
 		//skip the 'merge' tag, find a direct match first
 		if key.Tag == "!!merge" && followAlias {
 			log.Debug("Merge anchor")
-			err := traverseMergeAnchor(newMatches, candidate, value, operation)
+			err := traverseMergeAnchor(newMatches, candidate, value, wantedKey, splat)
 			if err != nil {
 				return err
 			}
-		} else if keyMatches(key, operation) {
+		} else if splat || keyMatches(key, wantedKey) {
 			log.Debug("MATCHED")
 			candidateNode := &CandidateNode{
 				Node:     value,
@@ -153,7 +272,7 @@ func doTraverseMap(newMatches *orderedmap.OrderedMap, candidate *CandidateNode,
 	return nil
 }
 
-func traverseMergeAnchor(newMatches *orderedmap.OrderedMap, originalCandidate *CandidateNode, value *yaml.Node, operation *Operation) error {
+func traverseMergeAnchor(newMatches *orderedmap.OrderedMap, originalCandidate *CandidateNode, value *yaml.Node, wantedKey string, splat bool) error {
 	switch value.Kind {
 	case yaml.AliasNode:
 		candidateNode := &CandidateNode{
@@ -161,10 +280,10 @@ func traverseMergeAnchor(newMatches *orderedmap.OrderedMap, originalCandidate *C
 			Path:     originalCandidate.Path,
 			Document: originalCandidate.Document,
 		}
-		return doTraverseMap(newMatches, candidateNode, operation)
+		return doTraverseMap(newMatches, candidateNode, wantedKey, true, splat)
 	case yaml.SequenceNode:
 		for _, childValue := range value.Content {
-			err := traverseMergeAnchor(newMatches, originalCandidate, childValue, operation)
+			err := traverseMergeAnchor(newMatches, originalCandidate, childValue, wantedKey, splat)
 			if err != nil {
 				return err
 			}
@@ -175,49 +294,6 @@ func traverseMergeAnchor(newMatches *orderedmap.OrderedMap, originalCandidate *C
 
 func traverseArray(candidate *CandidateNode, operation *Operation) (*list.List, error) {
 	log.Debug("operation Value %v", operation.Value)
-	if operation.Value == "[]" {
+	indices := []*yaml.Node{&yaml.Node{Value: operation.StringValue}}
-
+	return traverseArrayWithIndices(candidate, indices)
-		var contents = candidate.Node.Content
-		var newMatches = list.New()
-		var index int64
-		for index = 0; index < int64(len(contents)); index = index + 1 {
-
-			newMatches.PushBack(&CandidateNode{
-				Document: candidate.Document,
-				Path:     candidate.CreateChildPath(index),
-				Node:     contents[index],
-			})
-		}
-		return newMatches, nil
-
-	}
-
-	switch operation.Value.(type) {
-	case int64:
-		index := operation.Value.(int64)
-		indexToUse := index
-		contentLength := int64(len(candidate.Node.Content))
-		for contentLength <= index {
-			candidate.Node.Content = append(candidate.Node.Content, &yaml.Node{Tag: "!!null", Kind: yaml.ScalarNode, Value: "null"})
-			contentLength = int64(len(candidate.Node.Content))
-		}
-
-		if indexToUse < 0 {
-			indexToUse = contentLength + indexToUse
-		}
-
-		if indexToUse < 0 {
-			return nil, fmt.Errorf("Index [%v] out of range, array size is %v", index, contentLength)
-		}
-
-		return nodeToMap(&CandidateNode{
-			Node:     candidate.Node.Content[indexToUse],
-			Document: candidate.Document,
-			Path:     candidate.CreateChildPath(index),
-		}), nil
-	default:
-		log.Debug("argument not an int (%v), no array matches", operation.Value)
-		return list.New(), nil
-	}
-
 }

pkg/yqlib/operator_traverse_path_test.go

@@ -65,7 +65,7 @@ var traversePathOperatorScenarios = []expressionScenario{
 	},
 	{
 		skipDoc:    true,
-		document:   `{}`,
+		document:   ``,
 		expression: `.[1].a`,
 		expected: []string{
 			"D0, P[1 a], (!!null)::null\n",
@@ -150,12 +150,6 @@ var traversePathOperatorScenarios = []expressionScenario{
 			"D0, P[b c], (!!str)::frog\n",
 		},
 	},
-	{
-		skipDoc:    true,
-		document:   `[1,2,3]`,
-		expression: `.b`,
-		expected:   []string{},
-	},
 	{
 		description: "Traversing arrays by index",
 		document:    `[1,2,3]`,
@@ -274,6 +268,120 @@ var traversePathOperatorScenarios = []expressionScenario{
 			"D0, P[foobarList c], (!!str)::foobarList_c\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   `[a,b,c]`,
+		expression: `.[]`,
+		expected: []string{
+			"D0, P[0], (!!str)::a\n",
+			"D0, P[1], (!!str)::b\n",
+			"D0, P[2], (!!str)::c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `[a,b,c]`,
+		expression: `[]`,
+		expected: []string{
+			"D0, P[], (!!seq)::[]\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a[0]`,
+		expected: []string{
+			"D0, P[a 0], (!!str)::a\n",
+		},
+	},
+	{
+		description: "Select multiple indices",
+		document:    `{a: [a,b,c]}`,
+		expression:  `.a[0, 2]`,
+		expected: []string{
+			"D0, P[a 0], (!!str)::a\n",
+			"D0, P[a 2], (!!str)::c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a.[0, 2]`,
+		expected: []string{
+			"D0, P[a 0], (!!str)::a\n",
+			"D0, P[a 2], (!!str)::c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a.[0]`,
+		expected: []string{
+			"D0, P[a 0], (!!str)::a\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a[-1]`,
+		expected: []string{
+			"D0, P[a -1], (!!str)::c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a.[-1]`,
+		expected: []string{
+			"D0, P[a -1], (!!str)::c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a[-2]`,
+		expected: []string{
+			"D0, P[a -2], (!!str)::b\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a.[-2]`,
+		expected: []string{
+			"D0, P[a -2], (!!str)::b\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a[]`,
+		expected: []string{
+			"D0, P[a 0], (!!str)::a\n",
+			"D0, P[a 1], (!!str)::b\n",
+			"D0, P[a 2], (!!str)::c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a.[]`,
+		expected: []string{
+			"D0, P[a 0], (!!str)::a\n",
+			"D0, P[a 1], (!!str)::b\n",
+			"D0, P[a 2], (!!str)::c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a | .[]`,
+		expected: []string{
+			"D0, P[a 0], (!!str)::a\n",
+			"D0, P[a 1], (!!str)::b\n",
+			"D0, P[a 2], (!!str)::c\n",
+		},
+	},
 }
 
 func TestTraversePathOperatorScenarios(t *testing.T) {

pkg/yqlib/operators_test.go

@@ -38,7 +38,7 @@ func testScenario(t *testing.T, s *expressionScenario) {
 	if s.document != "" {
 		inputs, err = readDocuments(strings.NewReader(s.document), "sample.yml", 0)
 		if err != nil {
-			t.Error(err, s.document)
+			t.Error(err, s.document, s.expression)
 			return
 		}
 	} else {
@@ -55,7 +55,7 @@ func testScenario(t *testing.T, s *expressionScenario) {
 	results, err = treeNavigator.GetMatchingNodes(inputs, node)
 
 	if err != nil {
-		t.Error(err)
+		t.Error(fmt.Errorf("%v: %v", err, s.expression))
 		return
 	}
 	test.AssertResultComplexWithContext(t, s.expected, resultsToString(results), fmt.Sprintf("exp: %v\ndoc: %v", s.expression, s.document))
@@ -167,17 +167,17 @@ func documentScenarios(t *testing.T, title string, scenarios []expressionScenari
 			if s.document != "" {
 				node, err := treeCreator.ParsePath(s.expression)
 				if err != nil {
-					t.Error(err)
+					t.Error(err, s.expression)
 				}
 				err = streamEvaluator.Evaluate("sample.yaml", strings.NewReader(formattedDoc), node, printer)
 
 				if err != nil {
-					t.Error(err)
+					t.Error(err, s.expression)
 				}
 			} else {
 				err = streamEvaluator.EvaluateNew(s.expression, printer)
 				if err != nil {
-					t.Error(err)
+					t.Error(err, s.expression)
 				}
 			}
 

pkg/yqlib/path_parse_test.go

@@ -17,20 +17,35 @@ var pathTests = []struct {
 		append(make([]interface{}, 0), "[", "]"),
 		append(make([]interface{}, 0), "EMPTY", "COLLECT", "SHORT_PIPE"),
 	},
+	{
+		`.[]`,
+		append(make([]interface{}, 0), "TRAVERSE_ARRAY", "[", "]"),
+		append(make([]interface{}, 0), "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY"),
+	},
 	{
 		`.a[]`,
-		append(make([]interface{}, 0), "a", "SHORT_PIPE", "[]"),
+		append(make([]interface{}, 0), "a", "SHORT_PIPE", "TRAVERSE_ARRAY", "[", "]"),
-		append(make([]interface{}, 0), "a", "[]", "SHORT_PIPE"),
+		append(make([]interface{}, 0), "a", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE"),
 	},
 	{
 		`.a.[]`,
-		append(make([]interface{}, 0), "a", "SHORT_PIPE", "[]"),
+		append(make([]interface{}, 0), "a", "SHORT_PIPE", "TRAVERSE_ARRAY", "[", "]"),
-		append(make([]interface{}, 0), "a", "[]", "SHORT_PIPE"),
+		append(make([]interface{}, 0), "a", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE"),
+	},
+	{
+		`.a[0]`,
+		append(make([]interface{}, 0), "a", "SHORT_PIPE", "TRAVERSE_ARRAY", "[", "0 (int64)", "]"),
+		append(make([]interface{}, 0), "a", "0 (int64)", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE"),
+	},
+	{
+		`.a.[0]`,
+		append(make([]interface{}, 0), "a", "SHORT_PIPE", "TRAVERSE_ARRAY", "[", "0 (int64)", "]"),
+		append(make([]interface{}, 0), "a", "0 (int64)", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE"),
 	},
 	{
 		`.a[].c`,
-		append(make([]interface{}, 0), "a", "SHORT_PIPE", "[]", "SHORT_PIPE", "c"),
+		append(make([]interface{}, 0), "a", "SHORT_PIPE", "TRAVERSE_ARRAY", "[", "]", "SHORT_PIPE", "c"),
-		append(make([]interface{}, 0), "a", "[]", "SHORT_PIPE", "c", "SHORT_PIPE"),
+		append(make([]interface{}, 0), "a", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE", "c", "SHORT_PIPE"),
 	},
 	{
 		`[3]`,
@@ -44,18 +59,18 @@ var pathTests = []struct {
 	},
 	{
 		`.a | .[].b == "apple"`,
-		append(make([]interface{}, 0), "a", "PIPE", "[]", "SHORT_PIPE", "b", "EQUALS", "apple (string)"),
+		append(make([]interface{}, 0), "a", "PIPE", "TRAVERSE_ARRAY", "[", "]", "SHORT_PIPE", "b", "EQUALS", "apple (string)"),
-		append(make([]interface{}, 0), "a", "[]", "b", "SHORT_PIPE", "apple (string)", "EQUALS", "PIPE"),
+		append(make([]interface{}, 0), "a", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "b", "SHORT_PIPE", "apple (string)", "EQUALS", "PIPE"),
 	},
 	{
 		`(.a | .[].b) == "apple"`,
-		append(make([]interface{}, 0), "(", "a", "PIPE", "[]", "SHORT_PIPE", "b", ")", "EQUALS", "apple (string)"),
+		append(make([]interface{}, 0), "(", "a", "PIPE", "TRAVERSE_ARRAY", "[", "]", "SHORT_PIPE", "b", ")", "EQUALS", "apple (string)"),
-		append(make([]interface{}, 0), "a", "[]", "b", "SHORT_PIPE", "PIPE", "apple (string)", "EQUALS"),
+		append(make([]interface{}, 0), "a", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "b", "SHORT_PIPE", "PIPE", "apple (string)", "EQUALS"),
 	},
 	{
 		`.[] | select(. == "*at")`,
-		append(make([]interface{}, 0), "[]", "PIPE", "SELECT", "(", "SELF", "EQUALS", "*at (string)", ")"),
+		append(make([]interface{}, 0), "TRAVERSE_ARRAY", "[", "]", "PIPE", "SELECT", "(", "SELF", "EQUALS", "*at (string)", ")"),
-		append(make([]interface{}, 0), "[]", "SELF", "*at (string)", "EQUALS", "SELECT", "PIPE"),
+		append(make([]interface{}, 0), "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SELF", "*at (string)", "EQUALS", "SELECT", "PIPE"),
 	},
 	{
 		`[true]`,
@@ -89,8 +104,8 @@ var pathTests = []struct {
 	},
 	{
 		`{.a: .c, .b.[]: .f.g.[]}`,
-		append(make([]interface{}, 0), "{", "a", "CREATE_MAP", "c", "UNION", "b", "SHORT_PIPE", "[]", "CREATE_MAP", "f", "SHORT_PIPE", "g", "SHORT_PIPE", "[]", "}"),
+		append(make([]interface{}, 0), "{", "a", "CREATE_MAP", "c", "UNION", "b", "SHORT_PIPE", "TRAVERSE_ARRAY", "[", "]", "CREATE_MAP", "f", "SHORT_PIPE", "g", "SHORT_PIPE", "TRAVERSE_ARRAY", "[", "]", "}"),
-		append(make([]interface{}, 0), "a", "c", "CREATE_MAP", "b", "[]", "SHORT_PIPE", "f", "g", "SHORT_PIPE", "[]", "SHORT_PIPE", "CREATE_MAP", "UNION", "COLLECT_OBJECT", "SHORT_PIPE"),
+		append(make([]interface{}, 0), "a", "c", "CREATE_MAP", "b", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE", "f", "g", "SHORT_PIPE", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE", "CREATE_MAP", "UNION", "COLLECT_OBJECT", "SHORT_PIPE"),
 	},
 	{
 		`explode(.a.b)`,
@@ -122,7 +137,6 @@ var pathTests = []struct {
 		append(make([]interface{}, 0), "SELF", "ASSIGN_COMMENT", "str (string)"),
 		append(make([]interface{}, 0), "SELF", "str (string)", "ASSIGN_COMMENT"),
 	},
-
 	{
 		`.a.b tag="!!str"`,
 		append(make([]interface{}, 0), "a", "SHORT_PIPE", "b", "ASSIGN_TAG", "!!str (string)"),

pkg/yqlib/path_tokeniser.go

@@ -22,7 +22,7 @@ const (
 	CloseCollect
 	OpenCollectObject
 	CloseCollectObject
-	SplatOrEmptyCollect
+	TraverseArrayCollect
 )
 
 type Token struct {
@@ -49,8 +49,9 @@ func (t *Token) toString() string {
 		return "{"
 	} else if t.TokenType == CloseCollectObject {
 		return "}"
-	} else if t.TokenType == SplatOrEmptyCollect {
+	} else if t.TokenType == TraverseArrayCollect {
-		return "[]?"
+		return ".["
+
 	} else {
 		return "NFI"
 	}
@@ -114,23 +115,6 @@ func unwrap(value string) string {
 	return value[1 : len(value)-1]
 }
 
-func arrayIndextoken(precedingDot bool) lex.Action {
-	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
-		var numberString = string(m.Bytes)
-		startIndex := 1
-		if precedingDot {
-			startIndex = 2
-		}
-		numberString = numberString[startIndex : len(numberString)-1]
-		var number, errParsingInt = strconv.ParseInt(numberString, 10, 64) // nolint
-		if errParsingInt != nil {
-			return nil, errParsingInt
-		}
-		op := &Operation{OperationType: TraversePath, Value: number, StringValue: numberString}
-		return &Token{TokenType: OperationToken, Operation: op, CheckForPostTraverse: true}, nil
-	}
-}
-
 func numberValue() lex.Action {
 	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
 		var numberString = string(m.Bytes)
@@ -188,7 +172,8 @@ func initLexer() (*lex.Lexer, error) {
 	lexer.Add([]byte(`\(`), literalToken(OpenBracket, false))
 	lexer.Add([]byte(`\)`), literalToken(CloseBracket, true))
 
-	lexer.Add([]byte(`\.\[\]`), pathToken(false))
+	// lexer.Add([]byte(`\.\[\]`), pathToken(false)) // traverseCollect(false)
+	lexer.Add([]byte(`\.\[`), literalToken(TraverseArrayCollect, false))
 	lexer.Add([]byte(`\.\.`), opToken(RecursiveDescent))
 
 	lexer.Add([]byte(`,`), opToken(Union))
@@ -231,7 +216,7 @@ func initLexer() (*lex.Lexer, error) {
 
 	lexer.Add([]byte(`\s*\|=\s*`), opTokenWithPrefs(Assign, nil, &AssignOpPreferences{true}))
 
-	lexer.Add([]byte(`\.\[-?[0-9]+\]`), arrayIndextoken(true))
+	// lexer.Add([]byte(`\.\[-?[0-9]+\]`), arrayIndextoken(true)) // traverseCollect(true)
 
 	lexer.Add([]byte("( |\t|\n|\r)+"), skip)
 
@@ -254,8 +239,6 @@ func initLexer() (*lex.Lexer, error) {
 
 	lexer.Add([]byte(`"[^"]*"`), stringValue(true))
 
-	lexer.Add([]byte(`\[\]`), literalToken(SplatOrEmptyCollect, true))
-
 	lexer.Add([]byte(`\[`), literalToken(OpenCollect, false))
 	lexer.Add([]byte(`\]`), literalToken(CloseCollect, true))
 	lexer.Add([]byte(`\{`), literalToken(OpenCollectObject, false))
@@ -324,24 +307,16 @@ func (p *pathTokeniser) Tokenise(path string) ([]*Token, error) {
 func (p *pathTokeniser) handleToken(tokens []*Token, index int, postProcessedTokens []*Token) (tokensAccum []*Token, skipNextToken bool) {
 	skipNextToken = false
 	token := tokens[index]
-	if token.TokenType == SplatOrEmptyCollect {
-		if index > 0 && tokens[index-1].TokenType == OperationToken &&
-			tokens[index-1].Operation.OperationType == TraversePath {
-			// must be a splat without a preceding dot , e.g. .a[]
-			// lets put a pipe in front of it, and convert it to a traverse "[]" token
-			pipeOp := &Operation{OperationType: ShortPipe, Value: "PIPE"}
 
-			postProcessedTokens = append(postProcessedTokens, &Token{TokenType: OperationToken, Operation: pipeOp})
+	if token.TokenType == TraverseArrayCollect {
+		//need to put a traverse array then a collect token
+		// do this by adding traverse then converting token to collect
 
-			traverseOp := &Operation{OperationType: TraversePath, Value: "[]", StringValue: "[]"}
+		op := &Operation{OperationType: TraverseArray, StringValue: "TRAVERSE_ARRAY"}
-			token = &Token{TokenType: OperationToken, Operation: traverseOp, CheckForPostTraverse: true}
+		postProcessedTokens = append(postProcessedTokens, &Token{TokenType: OperationToken, Operation: op})
+
+		token = &Token{TokenType: OpenCollect}
 
-		} else {
-			// gotta be a collect empty array, we need to split this into two tokens
-			// one OpenCollect, the other CloseCollect
-			postProcessedTokens = append(postProcessedTokens, &Token{TokenType: OpenCollect})
-			token = &Token{TokenType: CloseCollect, CheckForPostTraverse: true}
-		}
 	}
 
 	if index != len(tokens)-1 && token.AssignOperation != nil &&
@@ -359,5 +334,21 @@ func (p *pathTokeniser) handleToken(tokens []*Token, index int, postProcessedTok
 		op := &Operation{OperationType: ShortPipe, Value: "PIPE"}
 		postProcessedTokens = append(postProcessedTokens, &Token{TokenType: OperationToken, Operation: op})
 	}
+	if index != len(tokens)-1 && token.CheckForPostTraverse &&
+		tokens[index+1].TokenType == OpenCollect {
+
+		op := &Operation{OperationType: ShortPipe, Value: "PIPE"}
+		postProcessedTokens = append(postProcessedTokens, &Token{TokenType: OperationToken, Operation: op})
+
+		op = &Operation{OperationType: TraverseArray}
+		postProcessedTokens = append(postProcessedTokens, &Token{TokenType: OperationToken, Operation: op})
+	}
+	if index != len(tokens)-1 && token.CheckForPostTraverse &&
+		tokens[index+1].TokenType == TraverseArrayCollect {
+
+		op := &Operation{OperationType: ShortPipe, Value: "PIPE"}
+		postProcessedTokens = append(postProcessedTokens, &Token{TokenType: OperationToken, Operation: op})
+
+	}
 	return postProcessedTokens, skipNextToken
 }

yq_test.go

@@ -1,60 +0,0 @@
-package main
-
-// import (
-// 	"fmt"
-// 	"runtime"
-// 	"testing"
-
-// 	"github.com/mikefarah/yq/v2/pkg/marshal"
-// 	"github.com/mikefarah/yq/v2/test"
-// )
-
-// func TestMultilineString(t *testing.T) {
-// 	testString := `
-// 	abcd
-// 	efg`
-// 	formattedResult, _ := marshal.NewYamlConverter().YamlToString(testString, false)
-// 	test.AssertResult(t, testString, formattedResult)
-// }
-
-// func TestNewYaml(t *testing.T) {
-// 	result, _ := newYaml([]string{"b.c", "3"})
-// 	formattedResult := fmt.Sprintf("%v", result)
-// 	test.AssertResult(t,
-// 		"[{b [{c 3}]}]",
-// 		formattedResult)
-// }
-
-// func TestNewYamlArray(t *testing.T) {
-// 	result, _ := newYaml([]string{"[0].cat", "meow"})
-// 	formattedResult := fmt.Sprintf("%v", result)
-// 	test.AssertResult(t,
-// 		"[[{cat meow}]]",
-// 		formattedResult)
-// }
-
-// func TestNewYaml_WithScript(t *testing.T) {
-// 	writeScript = "examples/instruction_sample.yaml"
-// 	expectedResult := `b:
-//   c: cat
-//   e:
-//   - name: Mike Farah`
-// 	result, _ := newYaml([]string{""})
-// 	actualResult, _ := marshal.NewYamlConverter().YamlToString(result, true)
-// 	test.AssertResult(t, expectedResult, actualResult)
-// }
-
-// func TestNewYaml_WithUnknownScript(t *testing.T) {
-// 	writeScript = "fake-unknown"
-// 	_, err := newYaml([]string{""})
-// 	if err == nil {
-// 		t.Error("Expected error due to unknown file")
-// 	}
-// 	var expectedOutput string
-// 	if runtime.GOOS == "windows" {
-// 		expectedOutput = `open fake-unknown: The system cannot find the file specified.`
-// 	} else {
-// 		expectedOutput = `open fake-unknown: no such file or directory`
-// 	}
-// 	test.AssertResult(t, expectedOutput, err.Error())
-// }