feat: Implement std.parseXmlJsonml

Author: rohitjangid

BUILD.bazel

@@ -17,6 +17,7 @@ go_library(
         "error_formatter.go",
         "imports.go",
         "interpreter.go",
+        "jsonml.go",
         "runtime_error.go",
         "thunks.go",
         "util.go",

builtins.go

@@ -1512,6 +1512,52 @@ func builtinParseYAML(i *interpreter, str value) (value, error) {
 	return jsonToValue(i, elems[0])
 }
 
+func builtinParseXmlJsonml(i *interpreter, str value) (value, error) {
+	sval, err := i.getString(str)
+	if err != nil {
+		return nil, err
+	}
+	s := sval.getGoString()
+
+	json, err := BuildJsonmlFromString(s)
+	if err != nil {
+		return nil, i.Error(fmt.Sprintf("failed to parse XML: %v", err.Error()))
+	}
+
+	arr, err := arrayToValue(i, json)
+	if err != nil {
+		return nil, err
+	}
+	return arr, nil
+}
+
+func arrayToValue(i *interpreter, json []interface{}) (*valueArray, error) {
+	var elements []*cachedThunk
+	var err error
+	for _, e := range json {
+		var val value
+		switch e := e.(type) {
+		case string:
+			val = makeValueString(e)
+		case map[string]interface{}:
+			val, err = jsonToValue(i, e)
+			if err != nil {
+				return nil, err
+			}
+		case []interface{}:
+			val, err = arrayToValue(i, e)
+			if err != nil {
+				return nil, err
+			}
+		default:
+			return nil, i.Error(fmt.Sprintf("invalid type for section: %v", reflect.TypeOf(e)))
+		}
+		elements = append(elements, readyThunk(val))
+	}
+
+	return makeValueArray(elements), nil
+}
+
 func jsonEncode(v interface{}) (string, error) {
 	buf := new(bytes.Buffer)
 	enc := json.NewEncoder(buf)
@@ -2520,6 +2566,7 @@ var funcBuiltins = buildBuiltinMap([]builtin{
 	&unaryBuiltin{name: "parseInt", function: builtinParseInt, params: ast.Identifiers{"str"}},
 	&unaryBuiltin{name: "parseJson", function: builtinParseJSON, params: ast.Identifiers{"str"}},
 	&unaryBuiltin{name: "parseYaml", function: builtinParseYAML, params: ast.Identifiers{"str"}},
+	&unaryBuiltin{name: "parseXmlJsonml", function: builtinParseXmlJsonml, params: ast.Identifiers{"str"}},
 	&generalBuiltin{name: "manifestJsonEx", function: builtinManifestJSONEx, params: []generalBuiltinParameter{{name: "value"}, {name: "indent"},
 		{name: "newline", defaultValue: &valueFlatString{value: []rune("\n")}},
 		{name: "key_val_sep", defaultValue: &valueFlatString{value: []rune(": ")}}}},

jsonml.go

@@ -0,0 +1,145 @@
+/*
+Copyright 2019 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package jsonnet
+
+import (
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"io"
+	"strings"
+)
+
+type stack struct {
+	elements []interface{}
+}
+
+func (s *stack) Push(e interface{}) {
+	s.elements = append(s.elements, e)
+}
+
+func (s *stack) Pop() (interface{}, error) {
+	if len(s.elements) == 0 {
+		return nil, errors.New("cannot pop from empty stack")
+	}
+	l := len(s.elements)
+	e := s.elements[l-1]
+	s.elements = s.elements[:l-1]
+	return e, nil
+}
+
+func (s *stack) Size() int {
+	return len(s.elements)
+}
+
+type jsonMLBuilder struct {
+	stack     *stack
+	currDepth int
+}
+
+// BuildJsonmlFromString returns a jsomML form of given xml string.
+func BuildJsonmlFromString(s string) ([]interface{}, error) {
+	b := newBuilder()
+	d := xml.NewDecoder(strings.NewReader(s))
+
+	for {
+		token, err := d.Token()
+		if err == io.EOF {
+			break
+		}
+
+		if err != nil {
+			return nil, err
+		}
+
+		if err := b.addToken(token); err != nil {
+			return nil, err
+		}
+	}
+
+	if b.stack.Size() == 0 {
+		// No nodes has been identified
+		return nil, fmt.Errorf("%s is not a valid XML", s)
+	}
+
+	return b.build(), nil
+}
+
+func newBuilder() *jsonMLBuilder {
+	return &jsonMLBuilder{
+		stack: &stack{},
+	}
+}
+
+func (b *jsonMLBuilder) addToken(token xml.Token) error {
+	switch token.(type) {
+	case xml.StartElement:
+		// check for multiple roots
+		if b.currDepth == 0 && b.stack.Size() > 0 {
+			// There are multiple root elements
+			return errors.New("XML cannot have multiple root elements")
+		}
+
+		t := token.(xml.StartElement)
+		node := []interface{}{t.Name.Local}
+		// Add Attributes
+		if len(t.Attr) > 0 {
+			attr := make(map[string]interface{})
+			for _, a := range t.Attr {
+				attr[a.Name.Local] = a.Value
+			}
+			node = append(node, attr)
+		}
+		b.stack.Push(node)
+		b.currDepth++
+	case xml.CharData:
+		t := token.(xml.CharData)
+		s := strings.TrimSpace(string(t))
+		if len(s) > 0 {
+			// Skip whitespace only string
+			b.appendToLastNode(string(t))
+		}
+	case xml.EndElement:
+		b.squashLastNode()
+		b.currDepth--
+	}
+
+	return nil
+}
+
+func (b *jsonMLBuilder) build() []interface{} {
+	root, _ := b.stack.Pop()
+	return root.([]interface{})
+}
+
+func (b *jsonMLBuilder) appendToLastNode(e interface{}) {
+	if b.stack.Size() == 0 {
+		return
+	}
+	node, _ := b.stack.Pop()
+	n := node.([]interface{})
+	n = append(n, e)
+	b.stack.Push(n)
+}
+
+func (b *jsonMLBuilder) squashLastNode() {
+	if b.stack.Size() < 2 {
+		return
+	}
+	n, _ := b.stack.Pop()
+	b.appendToLastNode(n)
+}

linter/internal/types/stdlib.go

@@ -106,13 +106,14 @@ func prepareStdlib(g *typeGraph) {
 
 		// Parsing
 
-		"parseInt":   g.newSimpleFuncType(numberType, "str"),
-		"parseOctal": g.newSimpleFuncType(numberType, "str"),
-		"parseHex":   g.newSimpleFuncType(numberType, "str"),
-		"parseJson":  g.newSimpleFuncType(jsonType, "str"),
-		"parseYaml":  g.newSimpleFuncType(jsonType, "str"),
-		"encodeUTF8": g.newSimpleFuncType(numberArrayType, "str"),
-		"decodeUTF8": g.newSimpleFuncType(stringType, "arr"),
+		"parseInt":       g.newSimpleFuncType(numberType, "str"),
+		"parseOctal":     g.newSimpleFuncType(numberType, "str"),
+		"parseHex":       g.newSimpleFuncType(numberType, "str"),
+		"parseJson":      g.newSimpleFuncType(jsonType, "str"),
+		"parseYaml":      g.newSimpleFuncType(jsonType, "str"),
+		"parseXmlJsonml": g.newSimpleFuncType(jsonType, "str"),
+		"encodeUTF8":     g.newSimpleFuncType(numberArrayType, "str"),
+		"decodeUTF8":     g.newSimpleFuncType(stringType, "arr"),
 
 		// Manifestation
 
@@ -152,7 +153,7 @@ func prepareStdlib(g *typeGraph) {
 		"minArray":      g.newFuncType(anyArrayType, []ast.Parameter{required("arr"), optional("keyF")}),
 		"maxArray":      g.newFuncType(anyArrayType, []ast.Parameter{required("arr"), optional("keyF")}),
 		"contains":      g.newSimpleFuncType(boolType, "arr", "elem"),
-		"avg":		    	 g.newSimpleFuncType(numberType, "arr"),	
+		"avg":           g.newSimpleFuncType(numberType, "arr"),
 		"all":           g.newSimpleFuncType(boolArrayType, "arr"),
 		"any":           g.newSimpleFuncType(boolArrayType, "arr"),
 		"remove":        g.newSimpleFuncType(anyArrayType, "arr", "elem"),

testdata/builtinParseXmlJsonml.golden

@@ -0,0 +1,18 @@
+[
+   "svg",
+   {
+      "height": "100",
+      "width": "100"
+   },
+   [
+      "circle",
+      {
+         "cx": "50",
+         "cy": "50",
+         "fill": "red",
+         "r": "40",
+         "stroke": "black",
+         "stroke-width": "3"
+      }
+   ]
+]

testdata/builtinParseXmlJsonml.jsonnet

@@ -0,0 +1 @@
+std.parseXmlJsonml('<svg height="100" width="100"><circle cx="50" cy="50" fill="red" r="40" stroke="black" stroke-width="3"></circle></svg>')