Tree-adjoining grammar

About: Tree-adjoining grammar is a research topic. Over the lifetime, 2491 publications have been published within this topic receiving 57813 citations.

Disambiguating grammars by exclusion of sub-parse trees

Abstract: A method is presented for disambiguation of grammars, based on the idea of excluding certain forbidden sub-parse trees. Combined with recent developments in the theory of parser generation for ambiguous grammars, the method disambiguates large classes of grammars guaranteeing that the generated language is unchanged.

A new set of constraint-free character recognition grammars

Abstract: A general pattern-recognition procedure for application to unconstrained alphanumeric characters is presented. The procedure is designed to allow hierarchical redescription of the input images in terms of significant elements only, and formal developments are given within the framework of elementary phrase-structure grammars. The extraction of the primitives associated with the terminal vocabularies of the grammars is always deterministic, and the productions of the parsers are characterized by a significant degree of topological fidelity. Preliminary experimental results indicate recognition rates comparable to the state of the art, but with a considerable reduction in computing time. >

Parsing String Generating Hypergraph Grammars

Abstract: A string generating hypergraph grammar is a hyperedge replacement grammar where the resulting language consists of string graphs i.e. hypergraphs modeling strings. With the help of these grammars, string languages like a n b n c n can be modeled that can not be generated by context-free grammars for strings. They are well suited to model discontinuous constituents in natural languages, i.e. constituents that are interrupted by other constituents. For parsing context-free Chomsky grammars, the Earley parser is well known. In this paper, an Earley parser for string generating hypergraph grammars is presented, leading to a parser for natural languages that is able to handle discontinuities.

From object algebras to attribute grammars

Abstract: Oliveira and Cook (2012) and Oliveira et al. (2013) have recently introduced object algebras as a program structuring technique to improve the modularity and extensibility of programs. We analyze the relationship between object algebras and attribute grammars (AGs), a formalism to augment context-free grammars with attributes. We present an extension of the object algebra technique with which the full class of L-attributed grammars - an important class of AGs that corresponds to one-pass compilers - can be encoded in Scala. The encoding is modular (attributes can be defined and type-checked separately), scalable (the size of the encoding is linear in the size of the AG specification) and compositional (each AG artifact is represented as a semantic object of the host language). To evaluate these claims, we have formalized the encoding and re-implemented a one-pass compiler for a subset of C with our technique. We also discuss how advanced features of modern AG systems, such as higher-order and parameterized attributes, reference attributes, and forwarding can be supported.