XPathlike

XPathlike is a theoretical query language intended to navigate and extract data from hierarchical structures such as XML and JSON. It is inspired by XPath but extends the model to unify querying across XML-like trees and JSON-like objects, enabling more seamless data integration. The language aims to provide a concise syntax for selecting nodes, values, and embedded structures while remaining familiar to users of traditional XPath.

Syntax in XPathlike centers on path expressions composed of slash separated steps, with optional axis specifiers and node tests. Predicates in brackets filter results, and a function library enables comparisons, type conversion, string operations, and boolean logic. The language supports common axes such as child and descendant, and adds practical variants for JSON objects and arrays, including tests for key presence and array length.

XPathlike operates on a data model that accommodates both XML-like trees and JSON-like trees, with a runtime capable of streaming evaluation to handle large documents. Result values can be node sequences or scalars, and predicates are evaluated in document order to preserve determinism. There is also an optional type system and namespace-like qualifiers to disambiguate names in mixed data collections.

Compared with XPath, XPathlike trades some traditional XML-specific features for broader data compatibility and incremental processing. It is often discussed in the context of data transformation pipelines, API responses, and web scraping tasks that involve mixed formats. Use in practice remains speculative, with implementations typically targeting research projects or language tooling rather than production standards.

XPathlike has no official standard status. It appears in theoretical discussions and academic proposals as a way to bridge XML and JSON querying. Related concepts include XPath, XQuery, and JSONPath.