Added support for `*=`

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

@@ -23,13 +23,19 @@ yq eval-all 'select(fileIndex == 0) * select(fileIndex == 1)' file1.yaml file2.y
 ```
 
 ## Multiply integers
-Running
+Given a sample.yml file of:
+```yaml
+a: 3
+b: 4
+```
+then
 ```bash
-yq eval --null-input '3 * 4'
+yq eval '.a *= .b' sample.yml
 ```
 will output
 ```yaml
-12
+a: 12
+b: 4
 ```
 
 ## Merge objects together, returning merged result only

pkg/yqlib/expression_tokeniser.go

@@ -100,7 +100,7 @@ func assignOpToken(updateAssign bool) lex.Action {
 	}
 }
 
-func multiplyWithPrefs() lex.Action {
+func multiplyWithPrefs(op *operationType) lex.Action {
 	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
 		prefs := multiplyPreferences{}
 		options := string(m.Bytes)
@@ -117,7 +117,7 @@ func multiplyWithPrefs() lex.Action {
 			prefs.DeepMergeArrays = true
 		}
 		prefs.TraversePrefs.DontFollowAlias = true
-		op := &Operation{OperationType: multiplyOpType, Value: multiplyOpType.Type, StringValue: options, Preferences: prefs}
+		op := &Operation{OperationType: op, Value: multiplyOpType.Type, StringValue: options, Preferences: prefs}
 		return &token{TokenType: operationToken, Operation: op}, nil
 	}
 }
@@ -476,9 +476,12 @@ func initLexer() (*lex.Lexer, error) {
 	lexer.Add([]byte(`\]\??`), literalToken(closeCollect, true))
 	lexer.Add([]byte(`\{`), literalToken(openCollectObject, false))
 	lexer.Add([]byte(`\}`), literalToken(closeCollectObject, true))
-	lexer.Add([]byte(`\*[\+|\?dn]*`), multiplyWithPrefs())
+	lexer.Add([]byte(`\*=[\+|\?dn]*`), multiplyWithPrefs(multiplyAssignOpType))
+	lexer.Add([]byte(`\*[\+|\?dn]*`), multiplyWithPrefs(multiplyOpType))
+
 	lexer.Add([]byte(`\+`), opToken(addOpType))
 	lexer.Add([]byte(`\+=`), opToken(addAssignOpType))
+
 	lexer.Add([]byte(`\-`), opToken(subtractOpType))
 	lexer.Add([]byte(`\-=`), opToken(subtractAssignOpType))
 	lexer.Add([]byte(`\$[a-zA-Z_-0-9]+`), getVariableOpToken())

pkg/yqlib/lib.go

@@ -57,6 +57,8 @@ var assignAnchorOpType = &operationType{Type: "ASSIGN_ANCHOR", NumArgs: 2, Prece
 var assignAliasOpType = &operationType{Type: "ASSIGN_ALIAS", NumArgs: 2, Precedence: 40, Handler: assignAliasOperator}
 
 var multiplyOpType = &operationType{Type: "MULTIPLY", NumArgs: 2, Precedence: 42, Handler: multiplyOperator}
+var multiplyAssignOpType = &operationType{Type: "MULTIPLY_ASSIGN", NumArgs: 2, Precedence: 42, Handler: multiplyAssignOperator}
+
 var addOpType = &operationType{Type: "ADD", NumArgs: 2, Precedence: 42, Handler: addOperator}
 var subtractOpType = &operationType{Type: "SUBTRACT", NumArgs: 2, Precedence: 42, Handler: subtractOperator}
 var alternativeOpType = &operationType{Type: "ALTERNATIVE", NumArgs: 2, Precedence: 42, Handler: alternativeOperator}

pkg/yqlib/operator_multiply.go

@@ -17,6 +17,21 @@ type multiplyPreferences struct {
 	AssignPrefs     assignPreferences
 }
 
+func createMultiplyOp(prefs interface{}) func(lhs *ExpressionNode, rhs *ExpressionNode) *ExpressionNode {
+	return func(lhs *ExpressionNode, rhs *ExpressionNode) *ExpressionNode {
+		return &ExpressionNode{Operation: &Operation{OperationType: multiplyOpType, Preferences: prefs},
+			Lhs: lhs,
+			Rhs: rhs}
+	}
+}
+
+func multiplyAssignOperator(d *dataTreeNavigator, context Context, expressionNode *ExpressionNode) (Context, error) {
+	var multiplyPrefs = expressionNode.Operation.Preferences
+	expressionNode.Operation.Preferences = nil
+
+	return compoundAssignFunction(d, context, expressionNode, createMultiplyOp(multiplyPrefs))
+}
+
 func multiplyOperator(d *dataTreeNavigator, context Context, expressionNode *ExpressionNode) (Context, error) {
 	log.Debugf("-- MultiplyOperator")
 	return crossFunction(d, context, expressionNode, multiply(expressionNode.Operation.Preferences.(multiplyPreferences)), false)

pkg/yqlib/operator_multiply_test.go

@@ -153,9 +153,10 @@ var multiplyOperatorScenarios = []expressionScenario{
 	},
 	{
 		description: "Multiply integers",
-		expression:  `3 * 4`,
+		document:    "a: 3\nb: 4",
+		expression:  `.a *= .b`,
 		expected: []string{
-			"D0, P[], (!!int)::12\n",
+			"D0, P[], (doc)::a: 12\nb: 4\n",
 		},
 	},
 	{