{
    "universalInfo":
    [
        {
            "category":"What is XPath?",
            "description":"XPath is a query language used for selecting nodes from XML and processing them. It may perform operations on strings, numbers and boolean values."
        },
        {
            "category":"What's new in XPath"
        }
    ],
    "VersionDiffs":
    [
        {
            "version":"2.0",
            "diffs":
            [
                "Added support for all XML simple types",
                "Many new functions (tripled instruction count)",
                "All expressions evaluate to sequence",
                "Introduces conditional expressions and for-loops"
            ]
        },
        {
            "version":"3.0",
            "diffs":
            [
                "Dynamic function calls (function may be called without being referenced by name (find function in collection and call)",
                "Inline functions",
                "Namespace literals - Namespace may be embedded into function name",
                "Support for union types - collections containing elements of different types",
                "Mapping operator - '!' performs evaluation for each element in sequence and concatenates results",
                "Introduced maps"
            ]
        },
        {
            "version":"3.1",
            "diffs":
            [
                "New operator for function chaining '=>'",
                "Introduced maps that store data in pair 'key:value' - 'map{ key : value, key : value }'",
                "Introduced arrays - they differ from sequences in that they can be nested 'array{1, 5, 7, (10 to 20)}'"
            ]
        }
    ]


}