Map -> XML 変換

keyValueXml4.groovy

def kvmap = [
  key1: "value1",
  key2: "value2",
  key3: [
    "key3-1" : "value3-1",
    "key3-2" : "value3-2",
  ],
]

sw = new StringWriter()
xml = new groovy.xml.MarkupBuilder(sw);
xml.doubleQuotes = true
xml.langs(type: 'current') { visit kvmap }

def visit(Map m)    { m.each { k, v -> xml."$k" { visit v } } }
def visit(String s) { xml.mkp.yield s }

def expect = '''\
<langs type="current">
  <key1>value1</key1>
  <key2>value2</key2>
  <key3>
    <key3-1>value3-1</key3-1>
    <key3-2>value3-2</key3-2>
  </key3>
</langs>'''

assert sw.toString() == expect