Departmental Papers (CIS)
Date of this Version
7-2012
Document Type
Conference Paper
Recommended Citation
Rajeev Alur and Loris D'Antoni, "Streaming Tree Transducers", Lecture Notes in Computer Science: Automata, Languages, and Programming 7392, 42-53. July 2012. http://dx.doi.org/10.1007/978-3-642-31585-5_8
Abstract
Theory of tree transducers provides a foundation for understanding expressiveness and complexity of analysis problems for specification languages for transforming hierarchically structured data such as XML documents. We introduce streaming tree transducers as an analyzable, executable, and expressive model for transforming unranked ordered trees (and hedges) in a single pass. Given a linear encoding of the input tree, the transducer makes a single left-to-right pass through the input, and computes the output in linear time using a finite-state control, a visibly pushdown stack, and a finite number of variables that store output chunks that can be combined using the operations of string-concatenation and tree-insertion. We prove that the expressiveness of the model coincides with transductions definable using monadic second-order logic (MSO). Existing models of tree transducers either cannot implement all MSO-definable transformations, or require regular look ahead that prohibits single-pass implementation. We show a variety of analysis problems such as type-checking and checking functional equivalence are decidable for our model.
Subject Area
CPS Theory
Publication Source
Lecture Notes in Computer Science: Automata, Languages, and Programming
Volume
7392
Start Page
42
Last Page
53
DOI
10.1007/978-3-642-31585-5_8
Copyright/Permission Statement
The original publication is available at www.springerlink.com
Date Posted: 18 July 2012
Comments
From the 39th International Colloquium, ICALP 2012, Warwick, UK, July 9-13, 2012.