exports ParseAstToJsonObject and ParseJsonObjectToAst

Author: junyulah

defBox.go

@@ -6,6 +6,7 @@ import (
 )
 
 var DefBox = &Sandbox{map[string]*BoxFunc{
+	// (if, conditionExp, successExp, failExp)
 	"if": ToLazySandboxFun(func(args []interface{}, attachment interface{}, pcpServer *PcpServer) (interface{}, error) {
 		if len(args) < 2 || len(args) > 3 {
 			return nil, errors.New("if grammer error. if must have at least 2 params, at most 3 params. eg: [\"if\", true, 1, 0], [\"if\", true, 1]")

pcpServer.go

@@ -30,8 +30,7 @@ func (pcpServer *PcpServer) Execute(source string, attachment interface{}) (inte
 
 // @param arr. Pure Json Object.
 func (pcpServer *PcpServer) ExecuteJsonObj(arr interface{}, attachment interface{}) (interface{}, error) {
-	ast := parseAst(arr)
-	return pcpServer.ExecuteAst(ast, attachment)
+	return pcpServer.ExecuteAst(ParseJsonObjectToAst(arr), attachment)
 }
 
 func (p *PcpServer) ExecuteAst(ast interface{}, attachment interface{}) (interface{}, error) {
@@ -47,6 +46,7 @@ func (p *PcpServer) ExecuteAst(ast interface{}, attachment interface{}) (interfa
 
 				var err error = nil
 
+				// resolve params in concurrent way
 				for i, param := range funNode.params {
 					wg.Add(1)
 					go func(i int, param interface{}) {
@@ -78,7 +78,8 @@ func (p *PcpServer) ExecuteAst(ast interface{}, attachment interface{}) (interfa
 	return ast, nil
 }
 
-func parseAst(source interface{}) interface{} {
+// convert source object to ast
+func ParseJsonObjectToAst(source interface{}) interface{} {
 	switch arr := source.(type) {
 	case []interface{}:
 		if len(arr) == 0 {
@@ -87,13 +88,13 @@ func parseAst(source interface{}) interface{} {
 
 		switch head := arr[0].(type) {
 		case string:
-			if head == "'" {
+			if head == "'" { // escape parsing array
 				return arr[1:]
 			} else {
 				var params []interface{}
 
 				for i := 1; i < len(arr); i++ {
-					params = append(params, parseAst(arr[i]))
+					params = append(params, ParseJsonObjectToAst(arr[i]))
 				}
 
 				return FunNode{head, params}
@@ -106,6 +107,25 @@ func parseAst(source interface{}) interface{} {
 	}
 }
 
+// convert ast to source object
+func ParseAstToJsonObject(ast interface{}) interface{} {
+	switch funNode := ast.(type) {
+
+	case FunNode:
+		list := []interface{}{funNode.funName}
+		for _, param := range funNode.params {
+			list = append(list, ParseAstToJsonObject(param))
+		}
+		return list
+
+	case []interface{}:
+		return append([]interface{}{"'"}, funNode...)
+
+	default:
+		return funNode
+	}
+}
+
 // NewPcpServer merge sandbox with default sandbox
 func NewPcpServer(sandbox *Sandbox) *PcpServer {
 	return &PcpServer{sandbox}

pcpServer_test.go

@@ -259,3 +259,32 @@ func TestNotEqualFunction(t *testing.T) {
 	runPcpCall(t, pcpServer, `["!=", "a", "A"]`, true)
 	runPcpCallExpectError(t, pcpServer, `["!=", 1]`)
 }
+
+func runParseAstJson(t *testing.T, source string) {
+	var arr interface{}
+	err := json.Unmarshal([]byte(source), &arr)
+	if err != nil {
+		t.Errorf(err.Error())
+	}
+	ast := ParseJsonObjectToAst(arr)
+
+	bs, err := json.Marshal(ParseAstToJsonObject(ast))
+	if err != nil {
+		t.Errorf(err.Error())
+	}
+
+	assertEqual(t, string(bs), source, "")
+}
+
+func TestParseAstToJsonObject(t *testing.T) {
+	runParseAstJson(t, "1")
+	runParseAstJson(t, `"hello"`)
+	runParseAstJson(t, `true`)
+	runParseAstJson(t, `null`)
+	runParseAstJson(t, `{}`)
+	runParseAstJson(t, `["'",1,2,3]`) // [1,2,3] <=> [',1,2,3]
+	runParseAstJson(t, `["if",true,["get",3]]`)
+	runParseAstJson(t, `["'",true,["'",3]]`)
+	runParseAstJson(t, `["if",true,["'","ok"]]`)
+	runParseAstJson(t, `{"a":[1,2,3]}`)
+}