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49
A Formal Model for an Expressive Fragment of XSLT
, 2000
"... The extension of the XSL (eXtensible Style sheet Language) by variables and passing of data values between template rules has generated a powerful XML query language: XSLT (eXtensible Style sheet Language Transformations). An informal introduction to XSTL is given, on the bases of which a formal ..."
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Cited by 65 (17 self)
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The extension of the XSL (eXtensible Style sheet Language) by variables and passing of data values between template rules has generated a powerful XML query language: XSLT (eXtensible Style sheet Language Transformations). An informal introduction to XSTL is given, on the bases of which a formal model of a fragment of XSLT is defined. This formal model is in the spirit of tree transducers, and its semantics is defined by rewrite relations. It is shown that the expressive power of the fragment is already beyond that of most other XML query languages. Finally, important properties such as termination and closure under composition are considered.
Structured document transformations based on XSL
 In DBPL
, 1999
"... Abstract. Based on the recursion mechanism of the XML transformation language XSL, the document transformation language DTL is defined. First the instantiation DTL reg is considered that uses regular expressions as pattern language. This instantiation closely resembles the navigation mechanism of XS ..."
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Cited by 38 (12 self)
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Abstract. Based on the recursion mechanism of the XML transformation language XSL, the document transformation language DTL is defined. First the instantiation DTL reg is considered that uses regular expressions as pattern language. This instantiation closely resembles the navigation mechanism of XSL. For DTL reg the complexity of relevant decision problems such as termination of programs, usefulness of rules and equivalence of selection patterns, is addressed. Next, a much more powerful abstraction of XSL is considered that uses monadic secondorder logic formulas as pattern language (DTL mso). If DTL mso is restricted to topdown transformations (DTL mso d), then a computational model can be defined which is a natural generalization to unranked trees of topdown tree transducers with lookahead. The lookahead can be realized by a straightforward bottomup preprocessing pass through the document. The size of the output of an XSL program is at most exponential in the size of the input. By restricting copying in XSL a decidable fragment of DTL mso d programs is obtained which induces transformations of linear size increase (safe DTL mso d). It is shown that the emptiness and finiteness problems are decidable for ranges of DTL mso d programs and that the ranges are closed under intersection with generalized Document Type Definitions (DTDs). 1
Bottomup and Topdown Tree Series Transformations
 J. Autom. Lang. Combin
, 2000
"... We generalize bottomup tree transducers and topdown tree transducers to the concept of bottomup tree series transducer and topdown tree series transducer, respectively, by allowing formal tree series as output rather than trees, where a formal tree series is a mapping from output trees to some s ..."
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Cited by 37 (6 self)
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We generalize bottomup tree transducers and topdown tree transducers to the concept of bottomup tree series transducer and topdown tree series transducer, respectively, by allowing formal tree series as output rather than trees, where a formal tree series is a mapping from output trees to some semiring. We associate two semantics with a tree series transducer: a mapping which transforms trees into tree series (for short: tree to tree series transformation or tts transformation), and a mapping which transforms tree series into tree series (for short: tree series transformation or tsts transformation). We show that the standard case of tree transducers is reobtained by choosing the boolean semiring under the tts semantics. Also, for each of the two types of tree series transducers and for both types of semantics, we prove a characterization which generalizes in a straightforward way the corresponding characterization result for the underlying tree transducer class. Mo...
A comparison of pebble tree transducers with macro tree transducers
 Acta Informatica
, 2003
"... Abstract. The npebble tree transducer was recently proposed as a model for XML query languages. The four main results on deterministic transducers are: First, (1) the translation τ of an npebble tree transducer can be realized by a composition of n + 1 0pebble tree transducers. Next, the pebble t ..."
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Cited by 37 (10 self)
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Abstract. The npebble tree transducer was recently proposed as a model for XML query languages. The four main results on deterministic transducers are: First, (1) the translation τ of an npebble tree transducer can be realized by a composition of n + 1 0pebble tree transducers. Next, the pebble tree transducer is compared with the macro tree transducer, a wellknown model for syntaxdirected semantics, with decidable type checking. The 0pebble tree transducer can be simulated by the macro tree transducer, which, by the first result, implies that (2) τ can be realized by an (n+1)fold composition of macro tree transducers. Conversely, every macro tree transducer can be simulated by a composition of 0pebble tree transducers. Together these simulations prove that (3) the composition closure of npebble tree transducers equals that of macro tree transducers (and that of 0pebble tree transducers). Similar results hold in the nondeterministic case. Finally, (4) the output languages of deterministic npebble tree transducers form a hierarchy with respect to the number n of pebbles. 1
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
A Comparison of Tree Transductions defined by Monadic Second Order Logic and by Attribute Grammars
, 1998
"... . Two wellknown formalisms for the specication and computation of tree transductions are compared: the mso graph transducer and the attributed tree transducer with lookahead, respectively. The mso graph transducer, restricted to trees, uses monadic second order logic to dene the output tree in ..."
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Cited by 30 (8 self)
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. Two wellknown formalisms for the specication and computation of tree transductions are compared: the mso graph transducer and the attributed tree transducer with lookahead, respectively. The mso graph transducer, restricted to trees, uses monadic second order logic to dene the output tree in terms of the input tree. The attributed tree transducer is an attribute grammar in which all attributes are trees; it is preceded by a lookahead phase in which all attributes have nitely many values. The main result is that these formalisms are equivalent, i.e., that the attributed tree transducer with lookahead is an appropriate implementation model for the tree transductions that are speciable in mso logic. This result holds for mso graph transducers that produce trees with shared subtrees. If no sharing is allowed, the attributed tree transducer satises the single use restriction. 1 Introduction Formulas of monadic second order (mso) logic can be used to express properti...
Composition of functions with accumulating parameters
 Journal of Functional Programming
, 2004
"... Many functional programs with accumulating parameters are contained in the class of macro tree transducers. We present a program transformation technique that can be used to solve the efficiency problems due to creation and consumption of intermediate data structures in compositions of such function ..."
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Cited by 21 (9 self)
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Many functional programs with accumulating parameters are contained in the class of macro tree transducers. We present a program transformation technique that can be used to solve the efficiency problems due to creation and consumption of intermediate data structures in compositions of such functions, where classical deforestation techniques fail. In order to do so, given two macro tree transducers under appropriate restrictions, we construct a single macro tree transducer that implements the composition of the two original ones. The imposed restrictions are more liberal than those in the literature on macro tree transducer composition, thus generalising previous results.
MSO definable string transductions and twoway finitestate transducers
 ACM Trans. Comput. Logic
, 2001
"... String transductions that are definable in monadic secondorder (mso) logic (without the use of parameters) are exactly those realized by deterministic twoway finite state transducers. Nondeterministic mso definable string transductions (i.e., those definable with the use of parameters) correspond ..."
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Cited by 20 (3 self)
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String transductions that are definable in monadic secondorder (mso) logic (without the use of parameters) are exactly those realized by deterministic twoway finite state transducers. Nondeterministic mso definable string transductions (i.e., those definable with the use of parameters) correspond to compositions of two nondeterministic twoway finite state transducers that have the finite visit property. Both families of mso definable string transductions are characterized in terms of Hennie machines, i.e., twoway finite state transducers with the finite visit property that are allowed to rewrite their input tape.
Macro Tree Translations of Linear Size Increase are MSO Definable
 SIAM J. Comput
, 2001
"... Abstract. The first main result is that if a macro tree translation is of linear size increase, i.e., if the size of every output tree is linearly bounded by the size of the corresponding input tree, then the translation is MSO definable (i.e., definable in monadic secondorder logic). This gives a ..."
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Cited by 16 (6 self)
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Abstract. The first main result is that if a macro tree translation is of linear size increase, i.e., if the size of every output tree is linearly bounded by the size of the corresponding input tree, then the translation is MSO definable (i.e., definable in monadic secondorder logic). This gives a new characterization of the MSO definable tree translations in terms of macro tree transducers: they are exactly the macro tree translations of linear size increase. The second main result is that given a macro tree transducer, it can be decided whether or not its translation is MSO definable, and if it is then an equivalent MSO transducer can be constructed. Similar results hold for attribute grammars, which define a subclass of the macro tree translations.
On Minimalist Attribute Grammars and Macro Tree Transducers
 Linguistic Form and its Computation
"... In this paper we extend the work by Michaelis (1999) which shows how to encode an arbitrary Minimalist Grammar in the sense of Stabler (1997) into a weakly equivalent multiple contextfree grammar (MCFG). By viewing MCFGrules as terms in a free Lawvere theory we can translate a given MCFG into a ..."
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Cited by 12 (4 self)
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In this paper we extend the work by Michaelis (1999) which shows how to encode an arbitrary Minimalist Grammar in the sense of Stabler (1997) into a weakly equivalent multiple contextfree grammar (MCFG). By viewing MCFGrules as terms in a free Lawvere theory we can translate a given MCFG into a regular tree grammar. The latter is characterizable by both a tree automaton and a corresponding formula in monadic secondorder (MSO) logic. The trees of the resulting regular tree language are then unpacked into the intended \linguistic" trees both through an MSO transduction based upon treewalking automata and through a macro tree transduction. This twostep approach gives an operational as well as a logical description of the tree sets involved. As an interlude we show that MCFGs can be regarded as a particularly simple attribute grammar. 1 Introduction Algebraic, logical and regular characterizations of (tree) languages provide a natural framework for the denotational and opera...