Showing papers on "L-attributed grammar published in 1993"
TL;DR: The handle-rewriting hypergraph grammars (HH Grammars) are introduced, based on the replacement of handles, i.e., of subhypergraphs consisting of one hyperedge together with its incident vertices, which can be characterized as the least solutions of certain systems of equations.
360 citations
19 Jun 1993
TL;DR: The Chomsky conjecture, that all languages recognized by the Lambek calculus are context-free, is proved and thus every basic categorial grammar is equivalent to a Lambek grammar.
Abstract: Basic categorial grammars are the context-free ones. Another kind of categorial grammars was introduced by J. Lambek (1958). These grammars are based on a syntactic calculus, known as the Lambek calculus. Chomsky (1963) conjectured that these grammars are also equivalent to context-free ones. Every basic categorial grammar (and thus every context-free grammar) is equivalent to a Lambek grammar. Conversely, some special kinds of Lambek grammars are context-free. These grammars use weakly unidirectional types, or types of order at most two. The main result of this paper says that Lambek grammars generate only context-free languages. Thus they are equivalent to context-free grammars and also to basic categorial grammars. The Chomsky conjecture, that all languages recognized by the Lambek calculus are context-free, is thus proved. >
203 citations
Journal Article•
TL;DR: A scheme to extend a recognition algorithm for Context-Free Grammars that can be used to derive polynomial-time recognition algorithms for a set of for-malisms that generate a superset of languages generated by CFG is presented.
Abstract: In this paper we present a scheme to extend a recognition algorithm for Context-Free Grammars (CFG) that can be used to derive polynomial-time recognition algorithms for a set of for-malisms that generate a superset of languages generated by CFG. We describe the scheme by developing a Cocke-Kasami-Younger (CKY)-like pure bottom-up recognition algorithm for Linear Indexed Grammars and show how it can be adapted to give algorithms for Tree Adjoining Grammars and Combinatory Categorial Grammars. This is the only polynomial-time recognition algorithm for Combinatory Categorial Grammars that we are aware of.The main contribution of this paper is the general scheme we propose for parsing a variety of formalisms whose derivation process is controlled by an explicit or implicit stack. The ideas presented here can be suitably modified for other parsing styles or used in the generalized framework set out by Lang (1990).
106 citations
22 Apr 1993
TL;DR: A genetic algorithm was developed for the purpose of inferring context free grammars and various forms of the grammar to generate the language of correctly balanced and nested brackets were successfully inferred.
Abstract: A genetic algorithm was developed for the purpose of inferring context free grammars. Results are reported on the inference of two grammars in this class. Various forms of the grammar to generate the language of correctly balanced and nested brackets were successfully inferred, but more complex grammars were not learnt with the resources available. The author also discusses various issues such as the representation of the grammars, the method of evaluation of the chromosomes and means of maintaining diversity in the population which will be important in future efforts to extend this work.
65 citations
Dissertation•
01 Jan 1993
55 citations
24 Aug 1993
TL;DR: An approach to interactive design tasks based on relational grammars, a general algorithm for the integration of grammar-based parsing in an interactive design environment, and an example scenario of the use of this formalism are presented.
Abstract: This paper describes an approach to interactive design tasks based on relational grammars. Relational grammars extend traditional one-dimensional string languages to higher dimensions through user-supplied domain relations. Design support takes the form of graphic inferences on partial input during design interaction with the user. Because of the nature of the rule definitions, design elements can be roughly 'sketched' without concern for their specific details. During the interaction process, the system installs constraints, adds default attributes, and/or builds higher-level composite structures out of the original input. An example scenario of the use of this formalism is presented supporting the task of document design. A general algorithm for the integration of grammar-based parsing in an interactive design environment is presented. >
48 citations
Proceedings Article•
01 Jun 1993
TL;DR: A variety of spatial grammar formalisms from an implementation standpoint are surveyed and two aspects of shape grammars are considered in detail: the conditions for reversibility of shape rules, and the recognition of planar shapes.
Abstract: The paper starts by giving a motivation for studying grammars in design and is based on considerations of style, discovery, and constructive techniques. This paper goes on to survey a variety of spatial grammar formalisms from an implementation standpoint. For each formalism, the salient computational issues pertaining to rule application are discussed. Two aspects of shape grammars are considered in detail: (a) the conditions for reversibility of shape rules, and (b) the recognition of planar shapes. An outline of subshape detection in U 23 is given.
45 citations
Book•
31 Jul 1993
TL;DR: The aim of this monograph is to clarify the role of notation in the development of grammar and to provide a framework for the subsequent development of formal grammar-based criticism.
Abstract: Foreword by Fernando Pereira. Preface. 1. Context-Free Grammars. 2. Bunch Notation. 3. Grammar Interpretations. 4. Recursive Descent. 5. Grammar Transformations. 6. Recursive Ascent. 7. Parse Forest. 8. Attribute Grammars. 9. LR Parsers. 10. Some Notes. References. Index.
38 citations
21 Apr 1993
TL;DR: The work presented in this paper is intended to give a general framework for studying tag parsing and it is shown that there are two distinct ways of representing the parse forest one of which involves the use of linear indexed grammars and the other the Use of context-free Grammars.
Abstract: We study parsing of tree adjoining grammars with particular emphasis on the use of shared forests to represent all the parse trees deriving a well-formed string. We show that there are two distinct ways of representing the parse forest one of which involves the use of linear indexed grammars and the other the use of context-free grammars. The work presented in this paper is intended to give a general framework for studying tag parsing. The schemes using lig and cfg to represent parses can be seen to underly most of the existing tag parsing algorithms.
34 citations
21 Apr 1993
TL;DR: Evidence that head-driven parsing strategies lead to efficiency gains over standard parsing strategies, for lexicalist, concatenative and unification-based grammars, is presented.
Abstract: We present evidence that head-driven parsing strategies lead to efficiency gains over standard parsing strategies, for lexicalist, concatenative and unification-based grammars. A head-driven parser applies a rule only after a phrase matching the head has been derived. By instantiating the head of the rule important information is obtained about the left-hand-side and the other elements of the ritht-hand-side. We have used two different head-driven parsers and a number of standard parsers to parse with lexicalist grammars for English and for Dutch. The results indicate that for important classes of lexicalist grammars it is fruitful to apply parsing strategies which are sensitive to the linguistic notion 'head'.
31 citations
Journal Article•
TL;DR: An extension to the shape-grammar formalism has been developed that allows qualities such as color, texture, material, function, and so on to be incorporated into the rules of a shape grammar, which can be used to represent simultaneously the composition of spatial and qualitative aspects of designs.
Abstract: Recent developments in the use of formal grammars in design are summarized here. A particular kind of formal grammar, called a shape grammar, has been used widely over the past decade
TL;DR: The generative capacity of these grammars is investigated (compared mainly with L-language families), as well as closure, decision and descriptional complexity questions.
Abstract: Some new generative devices are defined, called pattern grammars, starting from the way of identifying a language by a pattern in [2,5] (they can be viewed also as a generalization of Marcus contextual grammars [6]). The generative capacity of these grammars is investigated (compared mainly with L-language families), as well as closure, decision and descriptional complexity questions.
01 Jan 1993
TL;DR: The transformation engine of SIMON is an amalgamation of syntax-directed computation and content-oriented computation: the former is through higherorder extensions of attribute grammars whereas the latter is done by externally defined programs and it is for computation not naturally amenable to the syntax- directed paradigm.
Abstract: SUMMARY SIMON is a grammar-based transformation system for restructuring documents Its target applications include meta-level specification of document assembly, view definition and retrieval for multiview documents, and document type evolution The internal document model is based on attribute grammars, and it interfaces with external document models such as SGML through input and output conversion The transformation engine of SIMON is an amalgamation of syntax-directed computation and content-oriented computation: the former is through higherorder (and related) extensions of attribute grammars whereas the latter is done by externally defined programs and it is for computation not naturally amenable to the syntax-directed paradigm The current implementation of SIMON employs the higher-order extension proposed in [1] for the syntax-directed computation, and C++ for the content-oriented computation
TL;DR: The parsing problem for permutations phrase grammars is considered, and it is shown how efficient linear-time parsing can be achieved for permutation phrase Grammars satisfying an extended notion of the LL(1) property.
Abstract: A permutation phrase is a grammatical phrase that specifies a syntactic construct as any permutation of a set of constituent elements. Permutation phrases allow for the concise and natural expression of free-order constructs as found in programming languages and notations such as C, Cobol, BibTEX, and Unix command lines.The conciseness and clarity of expression that permutation phrase grammars offer over context-free grammars are illustrated through a case study of the declarations in C. The parsing problem for permutation phrase grammars is considered, and it is shown how efficient linear-time parsing can be achieved for permutation phrase grammars satisfying an extended notion of the LL(1) property.
22 Jun 1993
TL;DR: It is shown that the generative capacity of fts' is equal to that of nc-lfg's, and at least one NP-complete language is generated by fts'.
Abstract: A number of grammatical formalisms were introduced to define the syntax of natural languages. Among them are parallel multiple context-free grammars (pmcfg's) and lexical-functional grammars (lfg's). Pmcfg's and their subclass called multiple context-free grammars (mcfg's) are natural extensions of cfg's, and pmcfg's are known to be recognizable in polynomial time. Some subclasses of lfg's have been proposed, but they were shown to generate an NP-complete language. Finite state translation systems (fts') were introduced as a computational model of transformational grammars. In this paper, three subclasses of lfg's called nc-lfg's, dc-lfg's and fc-lfg's are introduced and the generative capacities of the above mentioned grammatical formalisms are investigated. First, we show that the generative capacity of fts' is equal to that of nc-lfg's. As relations among subclasses of those formalisms, it is shown that the generative capacities of deterministic fts', dc-lfg's, and pmcfg's are equal to each other, and the generative capacity of fc-lfg's is equal to that of mcfg's. It is also shown that at least one NP-complete language is generated by fts'. Consequently, deterministic fts', dc-lfg's and fc-lfg's can be recognized in polynomial time. However, fts' (and nc-lfg's) cannot, if P ≠ NP.
01 Jan 1993
TL;DR: It is shown how Attribute Grammars techniques can be adequate for evaluation of a quite large subclass of Natural Semantics specifications, including specifications of an arithmetic calculator, a tree transformation, a type-checker for an Algol-like language, and more.
Abstract: This paper describes the principles and the functionalities of the Minotaur system. Minotaur is a generic interactive environment based on the integration of the Centaur system and the FNC-2 system, two systems widely used to specify syntax and semantics of programming languages and generate efficient semantic tools from these specifications. We show how Attribute Grammars techniques can be adequate for evaluation of a quite large subclass of Natural Semantics specifications, including specifications of an arithmetic calculator, a tree transformation, a type-checker for an Algol-like language, ... For this subclass of Natural Semantics specifications, the Minotaur system automatically generates an incremental and efficient (in time and memory) evaluator which gives to Natural Semantics an industrial strength implementation.
25 Aug 1993
TL;DR: An algorithm is presented for automatically producing, from associations between their non-terminals and terminals, an attribute grammar which specifies the translation from one grammar to the other.
Abstract: This paper introduces the notion of a coupling of two grammars, defined by associations between their non-terminals and terminals. We present an algorithm for automatically producing, from these associations, an attribute grammar which specifies the translation from one grammar to the other.
24 Aug 1993
TL;DR: A new class of positional grammars is characterized, the extended pLALR Grammars, which can be translated into traditional LALR context free grammar with positional actions, and properly contains the class of pSLR grammARS for which a Yacc implementation has already been given.
Abstract: While in a string grammar the only possible spatial relation is the string concatenation, in a positional grammar other spatial relations can be defined and then used for describing high dimensional languages. We characterize a new class of positional grammars, the extended pLALR grammars, which can be translated into traditional LALR context free grammars with positional actions. A positional action is a procedure implementing a spatial relation. In this way, the parser for an extended pLALR language can be generated automatically by the tool Yacc with no more effort. Moreover, we show that the class of extended pLALR grammars properly contains the class of pSLR grammars for which a Yacc implementation has already been given. >
TL;DR: It is demonstrated by proving that actor grammars where, in each configuration, each message has a destination, are equivalent (in a well-defined sense) to arbitrary actor Grammars.
22 Jun 1993
TL;DR: It will be shown that using variables in lexical categories can increase the weak generative capacity of CCGs beyond the class of grammars listed above.
Abstract: Combinatory Categorial Grammars, CCGs, (Steedman 1985) have been shown by Weir and Joshi (1988) to generate the same class of languages as Tree-Adjoining Grammars (TAG), Head Grammars (HG), and Linear Indexed Grammars (LIG). In this paper, I will discuss the effect of using variables in lexical category assignments in CCGs. It will be shown that using variables in lexical categories can increase the weak generative capacity of CCGs beyond the class of grammars listed above.
TL;DR: A novel technique has been discovered by which the non‐termination that would otherwise occur is avoided by ‘guarding’ top‐down left‐recurrent language processors by non‐left‐recursive recognizers.
Abstract: Contrary to a widely-held belief, it is possible to construct executable specifications of language processors that use a top-down parsing strategy and which have structures that directly reflect the structure of grammars containing left-recursive productions. A novel technique has been discovered by which the non-termination that would otherwise occur is avoided by ‘guarding’ top-down left-recursive language processors by non-left-recursive recognizers. The use of a top-down parsing strategy increases modularity and the use of left-recursive productions facilitates specification of semantic equations. A combination of the two is of significant practical value because it results in modular and expressively clear executable specifications of language processors. The new approach has been tested in an attribute grammar programming environment that has been used in a number of projects including the development of natural language interfaces, SQL processors and circuit design transformers within a VLSI design package.
01 Aug 1993
TL;DR: This paper addresses the problem of how to exploit parallelism during the evaluation of the attributes of a derivation tree of a non-circular attribute grammar by defining a new variant of attribute grammars that incorporates a data-parallel attribution construct.
Abstract: This paper concerns the problem of how to exploit parallelism during the phases of compilation involving syntaxdirected analysis and translation. In particular, we address the problem of how to exploit parallelism during the evaluation of the attributes of a derivation tree of a non-circular attribute grammar. What distinguishes the ideas presented in this paper from earlier work on parallel attribute evaluation is the use of a data-parallel model: We define a new variant of attribute grammars, called scan grammars, that incorporates a data-parallel attribution construct.
TL;DR: The main idea behind this approach is to represent graphics (attributed graphs) by trees whose nodes are enriched with attributes by using algorithms that generalize Knuth's algorithm to attributed tree grammars.
26 Apr 1993
TL;DR: This paper proposes a technique and a language for specifying the performance attributes and attribute evaluators in PDL (Performance Description Language), and demonstrates its use for performance description and measurement.
Abstract: There are currently quite a few hardware description languages that support functional and structural description. However very few of them have features for rigorously describing the nonfunctional aspects of a system. Among such data are the performance attributes. We propose a technique and a language for specifying the performance attributes and attribute evaluators. Using this language, designated PDL (Performance Description Language), the design is viewed as a hierarchical composition of building blocks and the performance attributes of the design are described in terms of the building block performance. PDL and its execution environment are based on attributed grammars. Attribute grammars have been investigated well. In this paper, we introduce various constructs in PDL and demonstrate its use for performance description and measurement. The syntax of PDL continues to evolve at this time; the syntax used in this paper is only incidental.
TL;DR: Under some simple conditions, two-level Grammars can generate languages with unbounded numbers of terminal symbols; Type 0 grammars cannot.
Abstract: Under some simple conditions, two-level grammars can generate languages with unbounded numbers of terminal symbols; Type 0 grammars cannot.
TL;DR: This work defines and illustrates edge grammars and analyzes them in the context of formal language theory and results include hierarchy and decidability properties.