Regular Rooted Graph Grammars

نویسنده

  • Sacha Berger
چکیده

This thesis investigates a pragmatic approach to typing, static analysis and static optimization of Web query languages, in special the Web query language Xcerpt[43]. The approach is pragmatic in the sense, that no restriction on the types are made for decidability or efficiency reasons, instead precision is given up if necessary. Pragmatics on the dynamic side means to use types not only to ensure validity of objects operating on, but also influencing query selection based on types. A typing language for typing of graph structured data on the Web is introduced. The Graphs in mind are based on spanning trees with references, the typing languages is based on regular tree grammars [37, 38] with typed reference extensions. Beside ordered data in the spirit of XML, unordered data (i.e. in the spirit of the Xcerpt data model or RDF) can be modelled using regular expressions under unordered interpretation – this approach is new. An operational semantics for ordered and unordered types is given based on specialized regular tree automata[21] and counting constraints[67] (them again based on Presburger arithmetic formulae). Static type checking of Xcerpt query and construct terms is introduced, as well as optimization of Xcerpt query terms based on schema information.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Petri Net DAG Languages and Regular Tree Languages with Synchronization

A true-concurrency semantics is often given via pomsets. A pomset is an abstract directed acyclic graph that is in addition transitive: any grandson of a node is also a son of that node. We will drop this rather artificial transitive property in this paper and research abstract directed acyclic graphs (dags) as a true-concurrency semantics for Petri nets and their relation to regular languages ...

متن کامل

Two - Dimensional Regular Languages and Their Syntactic Characterization

In this paper, we deal with two-dimensional rectangular arrays for representing row and column structures such as symbol tables, spreadsheets, etc. Firstly we formalize the two-dimensional regular languages by pairs of regular expressions for rows and columns. Next we also introduce context-sensitive graph grammars called labeled grid graph grammars, which characterize the two-dimensional regul...

متن کامل

Alternating Regular Tree Grammars in the Framework of Lattice-Valued Logic

In this paper, two different ways of introducing alternation for lattice-valued (referred to as {L}valued)  regular tree grammars and {L}valued top-down tree automata are compared. One is the way which defines the alternating regular tree grammar, i.e., alternation is governed by the non-terminals of the grammar and the other is the way which combines state with alternation. The first way is ta...

متن کامل

Bisimulation of Context-free Grammars and of Pushdown Automata

We consider the bisimulation on the transition graphs of pushdown automata. First we give a characterization of bisimulation using the unfolded trees. We recall that the bisimulation is decidable for the subclass of preex transition graphs of context-free grammars. Furthermore any pushdown transition graph is a regular graph: it can be generated by iterated parallel rewritings of a deterministi...

متن کامل

PreRkTAG: Prediction of RNA Knotted Structures Using Tree Adjoining Grammars

Background: RNA molecules play many important regulatory, catalytic and structural <span style="font-variant: normal; font-style: norma...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2008