Split doc operator

pkg/yqlib/doc/Split into Documents.md

@@ -0,0 +1,31 @@
+# Split into Documents
+
+This operator splits all matches into separate documents
+
+## Split empty
+Running
+```bash
+yq eval --null-input 'splitDoc'
+```
+will output
+```yaml
+
+```
+
+## Split array
+Given a sample.yml file of:
+```yaml
+- a: cat
+- b: dog
+```
+then
+```bash
+yq eval '.[] | splitDoc' sample.yml
+```
+will output
+```yaml
+a: cat
+---
+b: dog
+```
+

pkg/yqlib/doc/headers/Split into Documents.md

@@ -0,0 +1,3 @@
+# Split into Documents
+
+This operator splits all matches into separate documents

pkg/yqlib/expression_tokeniser.go

@@ -241,6 +241,7 @@ func initLexer() (*lex.Lexer, error) {
 
 	lexer.Add([]byte(`documentIndex`), opToken(getDocumentIndexOpType))
 	lexer.Add([]byte(`di`), opToken(getDocumentIndexOpType))
+	lexer.Add([]byte(`splitDoc`), opToken(splitDocumentOpType))
 
 	lexer.Add([]byte(`style`), opAssignableToken(getStyleOpType, assignStyleOpType))
 

pkg/yqlib/lib.go

@@ -51,6 +51,7 @@ var shortPipeOpType = &operationType{Type: "SHORT_PIPE", NumArgs: 2, Precedence:
 
 var lengthOpType = &operationType{Type: "LENGTH", NumArgs: 0, Precedence: 50, Handler: lengthOperator}
 var collectOpType = &operationType{Type: "COLLECT", NumArgs: 0, Precedence: 50, Handler: collectOperator}
+var splitDocumentOpType = &operationType{Type: "SPLIT_DOC", NumArgs: 0, Precedence: 50, Handler: splitDocumentOperator}
 var getStyleOpType = &operationType{Type: "GET_STYLE", NumArgs: 0, Precedence: 50, Handler: getStyleOperator}
 var getTagOpType = &operationType{Type: "GET_TAG", NumArgs: 0, Precedence: 50, Handler: getTagOperator}
 var getCommentOpType = &operationType{Type: "GET_COMMENT", NumArgs: 0, Precedence: 50, Handler: getCommentsOperator}

pkg/yqlib/operator_split_document.go

@@ -0,0 +1,18 @@
+package yqlib
+
+import (
+	"container/list"
+)
+
+func splitDocumentOperator(d *dataTreeNavigator, matchMap *list.List, expressionNode *ExpressionNode) (*list.List, error) {
+	log.Debugf("-- splitDocumentOperator")
+
+	var index uint = 0
+	for el := matchMap.Front(); el != nil; el = el.Next() {
+		candidate := el.Value.(*CandidateNode)
+		candidate.Document = index
+		index = index + 1
+	}
+
+	return matchMap, nil
+}

pkg/yqlib/operator_split_document_test.go

@@ -0,0 +1,32 @@
+package yqlib
+
+import (
+	"testing"
+)
+
+var splitDocOperatorScenarios = []expressionScenario{
+	{
+		description: "Split empty",
+		document:    ``,
+		expression:  `splitDoc`,
+		expected: []string{
+			"D0, P[], (!!null)::\n",
+		},
+	},
+	{
+		description: "Split array",
+		document:    `[{a: cat}, {b: dog}]`,
+		expression:  `.[] | splitDoc`,
+		expected: []string{
+			"D0, P[0], (!!map)::{a: cat}\n",
+			"D1, P[1], (!!map)::{b: dog}\n",
+		},
+	},
+}
+
+func TestSplitDocOperatorScenarios(t *testing.T) {
+	for _, tt := range splitDocOperatorScenarios {
+		testScenario(t, &tt)
+	}
+	documentScenarios(t, "Split into Documents", splitDocOperatorScenarios)
+}

pkg/yqlib/operators_test.go

@@ -55,7 +55,7 @@ func testScenario(t *testing.T, s *expressionScenario) {
 		candidateNode := &CandidateNode{
 			Document:  0,
 			Filename:  "",
-			Node:      &yaml.Node{Tag: "!!null"},
+			Node:      &yaml.Node{Tag: "!!null", Kind: yaml.ScalarNode},
 			FileIndex: 0,
 		}
 		inputs.PushBack(candidateNode)
@@ -245,7 +245,7 @@ func documentOutput(t *testing.T, w *bufio.Writer, s expressionScenario, formatt
 		candidateNode := &CandidateNode{
 			Document:  0,
 			Filename:  "",
-			Node:      &yaml.Node{Tag: "!!null"},
+			Node:      &yaml.Node{Tag: "!!null", Kind: yaml.ScalarNode},
 			FileIndex: 0,
 		}
 		inputs.PushBack(candidateNode)

pkg/yqlib/stream_evaluator.go

@@ -35,7 +35,7 @@ func (s *streamEvaluator) EvaluateNew(expression string, printer Printer) error
 	candidateNode := &CandidateNode{
 		Document:  0,
 		Filename:  "",
-		Node:      &yaml.Node{Tag: "!!null"},
+		Node:      &yaml.Node{Tag: "!!null", Kind: yaml.ScalarNode},
 		FileIndex: 0,
 	}
 	inputList := list.New()