Pratt, T.W.: Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences 5 (1971) 560--595  Home/Search   Document Not in Database   Summary   Related Articles   Check

....to this, boundary crossing edges are indispensable in many modelling situations and are thus of widespread use in nested visual languages like Uml [41] Therefore, it is usually unavoidable to sacrifice compositionality when hierarchical graphs shall be applied for modelling purposes. Pratt [37, 38] was probably the first to consider such a kind of hierarchical graphs. The packages in his H graphs may depend on each other in an arbitrary way, also recursively. A particular kind of node replacement is used to define Hgraph languages that represent the semantics of programs, e.g. of Lisp ....

T. W. Pratt, Pair grammars, graph languages and string-to-graph translations, J. Comput. System Sci. 5 (1971), 560--595.

....with each other. Incremental integration tools assist in propagating changes and performing consistency analysis. The integration tools are driven by triple rules which define relationships between design documents. 1 Introduction Triple graph grammars, an extension of pair graph grammars [1], were introduced at the WG 94 workshop [2] Originally, they were motivated by integration problems in software engineering; later, they were applied to other domains as well. In general, triple graph grammars may be used for the specification of graph translations, coupling of graph structures, ....

....issues. Section 8 discusses the way we applied triple graph grammars and the experiences we made. Section 9 compares related work. Section 10 presents a short conclusion. 2 Triple Graph Grammars Pair graph grammars were introduced as early as 1971 by Pratt to specify graph tograph translations [1]. A pair grammar defines a set of pair productions which modify the participating graphs and update correspondences between nodes. Triple graph grammars [2] are an extension of pair graph grammars. They were motivated by the study of integration problems in software engineering environments [6] ....

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Pratt, T.W.: Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences 5 (1971) 560--595

....how ASGs and SRGs are related to each other, i.e. how an update of one graph is translated into an update of the related 120 CHAPTER 3. APPLICATION TO VISUAL LANGUAGES graph. In the most general case the relationships between ASGs and SRGs are modeled as coupled graph grammars as introduced in [80,93]. Assuming that any ASG graph grammar production is related to a single SRG graph grammar production and vice versa, it is a straightforward task to keep the ASG and SRG derivation histories and thereby the underlying graphs in a consistent state. In the absence of explicitly represented ....

T. W. Pratt. Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences, 5:560--595, 1971.

....we distinguish list and item frames by different shades of grey, and omit their labels. The graphs in Figure 1 contain two item frames, and a list frame that contains one or two item frames. 2 This representation forbids edges across frame boundaries (which other notions of hierarchical graphs [21, 8] allow) Only then graphs can be transformed in a modular way. However, the correspondence between the links of a frame and the points of its contents may induce an indirect relation between the contents and the context of that frame. The links of the list frames in Figure 1 are related to the ....

....allows to represent graphs by specific notations of the application domain in the user interface. This feature makes the language and its specified environment well suited for simulations and animations. Structured graphs have already been proposed in the context of graph transformation [21, 8], in graphical data base languages [20] and in system modelling languages [27] Graph shapes exist in Structured Gamma [10] for unstructured graphs) However, we are not aware of any other language or language proposal that features structured graphs, transformations, and classes together with ....

T. W. Pratt. Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences, 5:560--595, 1971.

....in a single transformation step. This turns our to be valuable for programming with hierarchical graph transformation. Hierarchical graphs are useful wherever large data structures are modelled by graphs, as in CASE tools [Got88, Tap99] or data base languages like Hyperlog [PH00] Pratt [Pra71] was probably the rst to consider a concept of hierarchical graph transformation wherein nodes could contain graphs. He used some kind of node replacement to de ne the semantics of programming languages. Pratt s graph concept was extended in [ES95] by allowing edges between the graphs contained ....

Terrence W. Pratt. Pair grammars, graph languages and stringto -graph translations. Journal of Computer and System Sciences, 5:560-595, 1971.

....in a single transformation step. This turns our to be valuable for programming with hierarchical graph transformation. Hierarchical graphs are useful wherever large data structures are modelled by graphs, as in CASE tools [Got88, Tap99] or data base languages like Hyperlog [PH00] Pratt [Pra71] was probably the first to consider a concept of hierarchical graph transformation wherein nodes could contain graphs. He used some kind of node replacement to define the semantics of programming languages. Pratt s graph concept was extended in [ES95] by allowing edges between the graphs ....

Terrence W. Pratt. Pair grammars, graph languages and stringto -graph translations. Journal of Computer and System Sciences, 5:560--595, 1971.

....and higher order predicates) These ideas could become the kernel of a complete graph transformation language that overcomes major deficiencies of today s graph transformation languages. Related Work Structured graphs have already been proposed by several authors: The hierarchical graphs of [24, 13] have compound nodes. Pratt [24] considers only language generation similar to Example 7, and Engels and Schurr [13] do not consider transformation at all. Schneider [27] considers graphs that have (simple) graphs as node and edge labels. The graphs of the old Agg system [20] support a rigid ....

....ideas could become the kernel of a complete graph transformation language that overcomes major deficiencies of today s graph transformation languages. Related Work Structured graphs have already been proposed by several authors: The hierarchical graphs of [24, 13] have compound nodes. Pratt [24] considers only language generation similar to Example 7, and Engels and Schurr [13] do not consider transformation at all. Schneider [27] considers graphs that have (simple) graphs as node and edge labels. The graphs of the old Agg system [20] support a rigid layering: Graphs, and the mappings ....

Terrence W. Pratt. Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences, 5:560--595, 1971.

....ut It should be noticed that the flattening process implies a loss of crucial structural information so that there is no chance to prove the converse of the theorem. 6 Conclusion We conclude this paper by briefly mentioning some related work and possible directions for future research. Pratt [15] was probably the first to consider a concept of hierarchical graph transformation, where he used a certain kind of node replacement to define the semantics of programming languages. His graph concept was extended in [6] by allowing edges between subgraphs contained in different nodes, but without ....

T. W. Pratt. Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences, 5:560--595, 1971.

....flavour (backtracking, and higher order procedures) These ideas could become the kernel of a complete graph transformation language that overcomes major deficiencies of today s languages. Related Work Structured graphs have already been proposed several authors: Hierarchical graphs of [15, 8] have compound nodes. Pratt [15] considers only language generation similar to example 2, and Engels and Schurr [8] do not (yet) consider transformation at all. The graphs of the old Agg system [13] support a rigid layering: Graphs and the mappings between them are abstracted to the nodes and ....

....higher order procedures) These ideas could become the kernel of a complete graph transformation language that overcomes major deficiencies of today s languages. Related Work Structured graphs have already been proposed several authors: Hierarchical graphs of [15, 8] have compound nodes. Pratt [15] considers only language generation similar to example 2, and Engels and Schurr [8] do not (yet) consider transformation at all. The graphs of the old Agg system [13] support a rigid layering: Graphs and the mappings between them are abstracted to the nodes and edges of the next layer. This ....

Terrence W. Pratt. Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences, 5:560--595, 1971.

....embedded in at(G) Therefore, the given diagram can be extended to a larger pushout diagram in the required way, retaining the injectivity of the occurrence morphism. ut 6 Conclusion We conclude this paper by brie y mentioning some related work and possible directions for future research. Pratt [14] was probably the rst to consider a concept of hierarchical graph transformation, where he used a certain kind of node replacement to de ne the semantics of programming languages. His graph concept was extended in [6] by allowing edges between subgraphs contained in di erent nodes, but without de ....

T. W. Pratt. Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences, 5:560-595, 1971.

....approach. Until now, we did not explain how ASGs and SRGs are related to each other, i.e. how an update of one graph is translated into an update of the related graph. In the most general case the relationships between ASGs and SRGs are modeled as coupled graph grammars as introduced in [58,59]. Assuming that any ASG graph grammar production is related to a single SRG graph grammar production and vice versa, it is a straightforward task to keep the ASG and SRG derivation histories and thereby the underlying graphs in a consistent state. In the absence of explicitly represented ....

T. W. Pratt. Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences, 5:560--595, 1971.

....and a sequence of target nodes. Finally, hierarchical graphs are graphs where a subgraph can be abstracted to one node and a bunch of edges between two abstracted subgraphs to one edge. 1 Another concept of hierarchical graphs was introduced by Pratt where nodes are labelled with graphs [Pra69, Pra71] Typing is an important concept for specification and programming. Transferred to graphs, this means that labels in typed graphs are divided into classes, called types, and that edges of a certain type are restricted to be incident only to certain types of source and target nodes. In a language ....

Terrence W. Pratt. Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences, 5:560--595, 1971.

....definition capabilities have been proposed [25, 26, 36] In fact, some of these models are hybrid models: text structure is defined by a grammar but the text operations may also be applied to text having no explicit grammar. Grammar based approaches are also common for text transformation systems [5, 16, 21, 27, 32, 37, 42]. The purpose of our model is to extend the capabilities offered by context free grammars as schemas. Compared to other approaches, the important and novel feature in our model is that it offers a uniform way for specifying all tasks (a) through (f) listed above. Our model is intended to support ....

....of subtrees in the argument tree with roots labelled by Front and matching the annotation SelfRef in the filter. 6.2 Transformations Many text operations can be described as parse tree transformations. Specifying parse tree transformations based on grammar transformations was introduced by Pratt [42] and by Aho and Ullman [4] with additional operators defined by others, including Furuta and Stotts [21] Kilpel inen et al. 30] Kuikka and Penttonen [32] Mamrak et al. 37] and in DSSSL [27] In this approach, a text transformation is described by a pair of grammars, input grammar and output ....

T.W. Pratt. Pair grammars, graph languages and string-to-graph translations. J. Computer and System Sciences 5, 560-595 (1971).

....having vertex and edge labels as well as vertex attributes in an extended version. There is a significant gap between definitions 3.1 and 3. 2 of this paper on one side and the graph model and rewriting approach supported by the application oriented graph grammar language PROGRES on the other side [19]. It is the purpose of this section to improve expressiveness of the graph model and the rewriting approach presented here as far as possible without destroying the proof of proposition 3.9. We will achieve this goal in the following steps: 1) First of all we have to introduce vertex and edge ....

Pratt T.W.: Pair Grammars, Graph Languages and String-to-Graph Translations, in: Journal of Computer and System Sciences, vol 5, San Diego: Academic Press (1971), 560-595

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Pratt, T.W.: Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences 5 (1971) 560--595

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Terrence W. Pratt. Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences (JCSS), 5(6):560--595, 1971.

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T. W. Pratt. Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences, 5:560-595, 1971.

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T. W. Pratt. Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences, 5:560-595, 1971.

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Terrence W. Pratt. Pair grammars, graph languages and string-to-graph translations. Journal of Computer and System Sciences 5, 560--595, 1971.

No context found.

Pratt T.W.: Pair Grammars, Graph Languages and String-to-Graph Translations, in: Journal of Computer and System Sciences, vol. 5, Academic Press (1971),560-595

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