1,354,679 research outputs found
Is there a fourth Futamura projection?
No full textThe three classic Futamura projections stand as a cornerstone in the development of partial evaluation. The observation by Futamura [1983], that compiler generators produced by his third projection are self-generating, and the insight by Klimov and Romanenko [1987], that Futamura's abstraction scheme can be continued beyond the three projections, are systematically investigated, and several new applications for compiler generators are proposed. Possible applications include the generation of quasi-online compiler generators and of compiler generators for domain-specific languages, and the bootstrapping of compiler generators from program specializers. From a theoretical viewpoint, there is equality between the class of self-generating compiler generators and the class of compiler generators produced by the third Futamura projection. This exposition may lead to new practical applications of compiler generators, as well as deepen our theoretical understanding of program specialization
Revisiting the Futamura Projections: A Diagrammatic Approach
No full textThe advent of language implementation tools such as PyPy and Truffle/Graal have reinvigorated and broadened interest in topics related to automatic compiler generation and optimization. Given this broader interest, we revisit the Futamura Projections using a novel diagram scheme. Through these diagrams we emphasize the recurring patterns in the Futamura Projections while addressing their complexity and abstract nature. We anticipate that this approach will improve the accessibility of the Futamura Projections and help foster analysis of those new tools through the lens of partial evaluation
The Second Futamura Projection for Type-Directed Partial Evaluation
No full textA generating extension of a program specializes the program with respect to part of the input. Applying a partial evaluator to the program trivially yields a generating extension, but specializing the partial evaluator with respect to the program often yields a more efficient one. This specialization can be carried out by the partial evaluator itself; in this case, the process is known as the second Futamura projection. We derive an ML implementation of the second Futamura projection for Type-Directed Partial Evaluation (TDPE). Due to the differences between `traditional', syntax-directed partial evaluation and TDPE, this derivation involves several conceptual and technical steps. These include a suitable formulation of the second Futamura projection and techniques for making TDPE amenable to self-application. In the context of the second Futamura projection, we also compare and relate TDPE with conventional offline partial evaluation.We demonstrate our technique with several examples, includingcompiler generation for Tiny, a prototypical imperative language
The Second Futamura Projection for Type-Directed Partial Evaluation
No full textA generating extension of a program specializes it with respect tosome specified part of the input. A generating extension of a programcan be formed trivially by applying a partial evaluator to the program;the second Futamura projection describes the automatic generationof non-trivial generating extensions by applying a partial evaluator toitself with respect to the programs.We derive an ML implementation of the second Futamura projection for Type-Directed Partial Evaluation (TDPE). Due to the differences between `traditional', syntax-directed partial evaluation andTDPE, this derivation involves several conceptual and technical steps.These include a suitable formulation of the second Futamura projection and techniques for making TDPE amenable to self-application. Inthe context of the second Futamura projection, we also compare andrelate TDPE with conventional offline partial evaluation.We demonstrate our technique with several examples, includingcompiler generation for Tiny, a prototypical imperative language
Lazy evaluation using first futamura projection framework truffle.
No full textThe paper defines a functional language with lazy evaluation. An interpreter using Futamura projection based interpreter framework Truffle is implemented. The interpreter is more performant than GHCi interpreter, but less performant than GHC compiler
An experiment with the fourth Futamura projection
No full textWe have experimentally validated the theoretical insight, that a compiler generator is an Ershov generating extension of a program specializer, by showing that an existing offline partial evaluator can perform the fourth Futamura projection. Specifically, an online and an offline partial evaluator for an imperative flowchart language were transformed into two new compiler generators by Romanenko’s classical partial evaluator Unmix. The two partial evaluators are described, as is a novel recursive method for polyvariant specialization. The new compiler generators are demonstrated by converting a universal parser into a parser generator. These results strongly indicate that existing partial evaluation techniques can be put to work on several new applications. To date, all previous compiler generators based on partial evaluation were either generated by self-application or handwritten. None of these works considered the generation of one compiler generator by another. <br/
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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