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53
The Design Space of Type Checkers for XML Transformation Languages
, 2004
"... We survey work on statically type checking XML transformations, covering a wide range of notations and ambitions. The concept of type may vary from idealizations of DTD to fullblown XML Schema or even more expressive formalisms. The notion of transformation may vary from clean and simple transd ..."
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Cited by 37 (6 self)
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We survey work on statically type checking XML transformations, covering a wide range of notations and ambitions. The concept of type may vary from idealizations of DTD to fullblown XML Schema or even more expressive formalisms. The notion of transformation may vary from clean and simple transductions to domainspecific languages or integration of XML in generalpurpose programming languages. Type annotations can be either explicit or implicit, and type checking ranges from exact decidability to pragmatic approximations. We characterize
Exact XML type checking in polynomial time
 In ICDT
, 2007
"... f on valid inputs conform to theoutput type? Since XML types are intrinsically more complex than the types found in ..."
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Cited by 32 (3 self)
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f on valid inputs conform to theoutput type? Since XML types are intrinsically more complex than the types found in
N– ary Queries by Tree Automata
 In 10th International Symposium on Database Programming Languages
, 2005
"... www.grappa.univlille3.fr/mostrare We investigate nary node selection queries in trees by successful runs of tree automata. We show that runbased nary queries capture MSO, contribute algorithms for enumerating answers of nary queries, and study the complexity of the problem. We investigate the ..."
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Cited by 22 (5 self)
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www.grappa.univlille3.fr/mostrare We investigate nary node selection queries in trees by successful runs of tree automata. We show that runbased nary queries capture MSO, contribute algorithms for enumerating answers of nary queries, and study the complexity of the problem. We investigate the subclass of runbased nary queries by unambiguous tree automata.
Towards practical typechecking for macro tree transducers
, 2007
"... Abstract. Macro tree transducers (mtt) are an important model that both covers many useful XML transformations and allows decidable exact typechecking. This paper reports our first step toward an implementation of mtt typechecker that has a practical efficiency. Our approach is to represent an input ..."
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Cited by 12 (1 self)
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Abstract. Macro tree transducers (mtt) are an important model that both covers many useful XML transformations and allows decidable exact typechecking. This paper reports our first step toward an implementation of mtt typechecker that has a practical efficiency. Our approach is to represent an input type obtained from a backward inference as an alternating tree automaton, in a style similar to Tozawa’s XSLT0 typechecking. In this approach, typechecking reduces to checking emptiness of an alternating tree automaton. We propose several optimizations (Cartesian factorization, state partitioning) on the backward inference process in order to produce much smaller alternating tree automata than the naive algorithm, and we present our efficient algorithm for checking emptiness of alternating tree automata, where we exploit the explicit representation of alternation for local optimizations. Our preliminary experiments confirm that our algorithm has a practical performance that can typecheck simple transformations with respect to the full XHTML in a reasonable time. 1
Efficient inclusion checking for deterministic tree automata and xml schemas
, 2007
"... Abstract. We present a new algorithm for testing language inclusion L(A) ⊆ L(B) between tree automata in time O(A  ∗ B) where B is deterministic. We extend this algorithm for testing inclusion between automata for unranked trees A and deterministic DTDs D in time O(A∗ Σ  ∗ D). No previo ..."
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Cited by 11 (4 self)
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Abstract. We present a new algorithm for testing language inclusion L(A) ⊆ L(B) between tree automata in time O(A  ∗ B) where B is deterministic. We extend this algorithm for testing inclusion between automata for unranked trees A and deterministic DTDs D in time O(A∗ Σ  ∗ D). No previous algorithms with these complexities exist. inria00192329, version 6 5 Mar 2009 1
XML transformation by treewalking transducers with invisible pebbles
 In PODS
, 2007
"... The pebble tree automaton and the pebble tree transducer are enhanced by additionally allowing an unbounded number of ‘invisible ’ pebbles (as opposed to the usual ‘visible’ ones). The resulting pebble tree automata recognize the regular tree languages (i.e., can validate all generalized DTD’s) and ..."
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Cited by 11 (1 self)
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The pebble tree automaton and the pebble tree transducer are enhanced by additionally allowing an unbounded number of ‘invisible ’ pebbles (as opposed to the usual ‘visible’ ones). The resulting pebble tree automata recognize the regular tree languages (i.e., can validate all generalized DTD’s) and hence can find all matches of MSO definable nary patterns. Moreover, when viewed as a navigational device, they lead to an XPathlike formalism that has a path expression for every MSO definable binary pattern. The resulting pebble tree transducers can apply arbitrary MSO definable tests to (the observable part of) their configurations, they (still) have a decidable typechecking problem, and they can model the recursion mechanism of XSLT. The time complexity of the typechecking problem for conjunctive queries that use MSO definable binary patterns can often be reduced through the use of invisible pebbles.
HigherOrder MultiParameter Tree Transducers . . .
, 2010
"... We introduce higherorder, multiparameter, tree transducers (HMTTs, for short), which are kinds of higherorder tree transducers that take input trees and output a (possibly infinite) tree. We study the problem of checking whether the tree generated by a given HMTT conforms to a given output specif ..."
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Cited by 11 (2 self)
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We introduce higherorder, multiparameter, tree transducers (HMTTs, for short), which are kinds of higherorder tree transducers that take input trees and output a (possibly infinite) tree. We study the problem of checking whether the tree generated by a given HMTT conforms to a given output specification, provided that the input trees conform to input specifications (where both input/output specifications are regular tree languages). HMTTs subsume higherorder recursion schemes and ordinary tree transducers, so that their verification has a number of potential applications to verification of functional programs using recursive data structures, including resource usage verification, string analysis, and exact typechecking of XMLprocessing programs. We propose a sound but incomplete verification algorithm for the HMTT verification problem: the algorithm reduces the verification problem to a modelchecking problem for higherorder recursion schemes extended with finite data domains, and then uses (an extension of) Kobayashi’s algorithm for modelchecking recursion schemes. While the algorithm is incomplete (indeed, as we show in the paper, the verification problem is undecidable in general), it is sound and complete for a subclass of HMTTs called linear HMTTs. We have applied our HMTT verification algorithm to various program verification problems and obtained promising results.
Typed Iterators for XML
"... XML transformations are very sensitive to types: XML types describe the tags and attributes of XML elements as well as the number, kind, and order of their subelements. Therefore, operations, even simple ones, that modify these features may affect the types of documents. Operations on XML document ..."
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Cited by 8 (1 self)
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XML transformations are very sensitive to types: XML types describe the tags and attributes of XML elements as well as the number, kind, and order of their subelements. Therefore, operations, even simple ones, that modify these features may affect the types of documents. Operations on XML documents are performed by iterators that, to be useful, need to be typed by a kind of polymorphism that goes beyond what currently exists. For this reason these iterators are not programmed but, rather, hardcoded in the language. However, this approach soon reaches its limits, as the hardcoded iterators cannot cover fairly standard usage scenarios. As a solution to this problem we propose a generic language to define iterators for XML data to be grafted on some host programming language. We show that our language mostly offers the required degree of polymorphism, study its formal properties, and show its expressiveness and practical impact by providing several usage examples and encodings.
A learning algorithm for topdown xml transformations
, 2009
"... A generalization from string to trees and from languages to translations is given of the classical result that any regular language can be learned from examples: it is shown that for any deterministic topdown tree transformation there exists a sample set of polynomial size (with respect to the mini ..."
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Cited by 7 (2 self)
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A generalization from string to trees and from languages to translations is given of the classical result that any regular language can be learned from examples: it is shown that for any deterministic topdown tree transformation there exists a sample set of polynomial size (with respect to the minimal transducer) which allows to infer the translation. Until now, only for string transducers and for simple relabeling tree transducers, similar results had been known. Learning of deterministic topdown tree transducers (dtops) is far more involved because a dtop can copy, delete, and permute its input subtrees. Thus, complex dependencies of labeled input to output paths need to be maintained by the algorithm. First, a MyhillNerode theorem is presented for dtops, which is interesting on its own. This theorem is then used to construct a learning algorithm for dtops. Finally, it is shown how our result can be applied to xml transformations (e.g. xslt programs). For this, a new dtdbased encoding of unranked trees by ranked ones is presented. Over such encodings, dtops can realize many practically interesting xml transformations which cannot be realized on firstchild/nextsibling encodings.