Top PDF Implementation of an LALR(1) Parser Generator

Implementation of an LALR(1) Parser Generator

Implementation of an LALR(1) Parser Generator

up the internal for the next action grammar Appendix D The whose is stored in array ACTION the selected if it has already been filled in with a If it has been then we have an action conf[r]

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Scalabison: A Tool for Recursive Ascent Descent Parser Generator

Scalabison: A Tool for Recursive Ascent Descent Parser Generator

When adapting a reduce action from the LALR state, the corresponding announce action is used if the relevant item is in the LC state. Otherwise (as seen in the example, without an item for rule 21), we are in a similar situation as we were with a shift action that does not immediately translate. There are two possibilities: one that the action corresponds to an item (or items) of the LALR state that are irrelevant to the LC state that uses it, or that it indicates parsing action beyond the recognition point of an item in the LC state. We detect the latter case by tracing the items (in the LALR state) associated with the action back to where they are generated. If we encounter an item that in the LC state is at its recognition point, we use an announce action. In this way, the reduce action on DEF is converted into an announce of rule 12. Otherwise the action is omitted from the LC state unless an “accept” action is possible (see next paragraph), in which case we use that action (as seen in Fig 1 for ‟}‟).
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A Systematic Approach to the Implementation of Attribute Grammars with Conventional Compiler Construction Tools

A Systematic Approach to the Implementation of Attribute Grammars with Conventional Compiler Construction Tools

grammars allowed (e.g., JavaCC supports LL(k) grammars, while ANTLR supports the aforementioned LL(*) parsing method, able to deal with unbounded look-ahead; additionally tools like Elkhound [30], SDF [10] or, under certain settings, Bison, provide support to arbitrary context-free grammars via the GLR parsing method [46]), by the expressiveness of its specification language (e.g., ANTLR or Tatoo support very sophisticated features, like grammar modularization, rule inheritance, etc.), by whether they include support for lexical specification (e.g., JavaCC, ANTLR) or whether it must be made by using a separating tool (e.g., CUP), and by many other features whose detailed analysis is beyond the scope of the present work. As was indicated, the patterns presented in this paper are applicable to most of these parser generators (in particular in those tools that support deterministic grammars; in tools like SDF, whose outcome is parse forests that must be subsequently disambiguated, the applicability of these patterns vanishes). Also, it is important to notice that, while many of these parser generation tools support the concept of semantic attribute, like attribute grammars (e.g., this terminology is explicitly included in ANTLR), it does not mean that these tools give direct support for attribute grammars. Indeed, in addition to managing semantic attributes, the essential aspect of attribute grammars is the support for a dependency-driven execution style: semantic evaluation is not necessarily coupled with parsing, but emerges as a consequence of the dependencies among attributes. In this way, the patterns introduced in this work make it possible to incorporate this computation style into specifications for parser generation tools, and, in consequence, to facilitate the subsequent refinement into more efficient implementations.
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Implementation of supersymmetric processes in the HERWIG event generator

Implementation of supersymmetric processes in the HERWIG event generator

In our implementation, supersymmetric particles do not radiate gluons. This assump- tion is reasonable if the decay lifetimes of the coloured sparticles (spartons) are much shorter than the QCD confinement scale. In particular, a stable gluino Lightest Supersym- metric Particle ( LSP ) is not simulated. The simulation of a long-lived light top squark would neglect effects due to gluon emission and hadronization.

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Design, Analysis and Implementation of DLL Clock Generator

Design, Analysis and Implementation of DLL Clock Generator

In this work the designed DLL achieves operation frequency of 280MHz with a multiplied output of 3GHz consideration power improvement was achieved in the design. The design shows improvement in power consumption but for better jitter performance different delay element can be used in place of current starved inverter. Further work can be carried out on implementation of programmable FM.

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Design and Implementation of Area Efficient BIST Based Vedic and Wallace Tree Multipliers on FPGA

Design and Implementation of Area Efficient BIST Based Vedic and Wallace Tree Multipliers on FPGA

Another simple approach to test any circuit is general ATPG technique shown in figure 3 in which direct test patterns are applied through ATGP to the DUT and to reduce the complexity we use a reference multiplier is a multiplier which surely works and gives a correct output so this multiplier is taken as a reference in order to compare with the multipliers present in the DUT ( Vedic and Wallace Tree ) then comparator is used to compare the both of these outputs in order to determine the corrections of the multipliers, then comparator gives the results pass or fail. We are testing the multipliers by inserting faults in to them and whenever our assumed golden signatures value matches with ORA output then the results shows pass irrespective of fault values (0 or 1).
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VHDL Implementation of High Speed and Low Power BIST Based Vedic Multiplier

VHDL Implementation of High Speed and Low Power BIST Based Vedic Multiplier

Three flip-flops are used with linear feed-back. The yield of the last flip-flop is XOR-ed with the controlled contribution of the enable pin. The output of the block is given as input to the first flip flop. The output of the first flip flop is XOR-ed with the second flip-flop to generate the first output bit. Thus if Enable input is low then the output of the TPG will drive to logic "0000". An active high signal will enable the hardware to generate a random 4-bit signal. This circuit generates a 4-bit random values using three registers, so relative low power consumption is used by this circuit. RTL schematic of Test Pattern Generator is shown in Fig 5.
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Why Implementation Matters: Evaluation of an Open source Constraint Grammar Parser

Why Implementation Matters: Evaluation of an Open source Constraint Grammar Parser

Our goals were partially fulfilled: while the speed of our parser falls short of that of VISL CG-3 — with the exception of the execution of very small grammars — we have made advances on the state- of-the-art free/open-source FST implementations of CG. We based our system on the fomacg compiler, and extended it in several ways. Our parser uses optimised FST application methods instead of the generic foma variant used by previous implementations, thereby achieving better performance. Further optimisations, both memory and runtime, were made by exploiting the properties of FSTs generated from a CG. We report real-world performance measurements with and without these optimisations, so their efficacy can be accurately evaluated. A new method for rule testing has also been proposed, which in theory is capable of reducing the worst-case complexity bound of CG application to O(n 2 k 2 log G).
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Know When to Hold 'Em: Shuffling Deterministically in a Parser for Nonconcatenative Grammars

Know When to Hold 'Em: Shuffling Deterministically in a Parser for Nonconcatenative Grammars

The results of our implementation demonstrate that deterministic application of shuffle constraints yields a dramatic improvement in the overall performance of a head-corner parser for G[r]

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Parsing and MWE Detection: Fips at the PARSEME Shared Task

Parsing and MWE Detection: Fips at the PARSEME Shared Task

Identifying multiword expressions (MWEs) in a sentence in order to ensure their proper processing in subsequent applications, like machine translation, and performing the syntactic analysis of the sentence are interrelated processes. In our approach, priority is given to parsing alter- natives involving collocations, and hence collocational information helps the parser through the maze of alternatives, with the aim to lead to substantial improvements in the performance of both tasks (collocation identification and parsing), and in that of a subsequent task (machine translation). In this paper, we are going to present our system and the procedure that we have followed in order to participate to the open track of the PARSEME shared task on automatic identification of verbal multiword expressions (VMWEs) in running texts.
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Head driven Parsing for Lexicalist Grammars: Experimental Results

Head driven Parsing for Lexicalist Grammars: Experimental Results

A parser in which application of a rule is driven by the left-most daughter, as it is for instance in a stan- dard bottom-up active chart parser, will consider the application of rule 1 [r]

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1.
													Natural language parsing using fuzzy canonical lr (1) parser

1. Natural language parsing using fuzzy canonical lr (1) parser

1) SNP VP (1.0) 11) VPv NP (0.1) 2) S aux NP VP (1.0) 12) VP v VP (0.1) 3) NPart n (0.2) 13) VP v NP VP (0.2) 4) NPpron (0.2) 14) VP v ADJP (0.1) 5) NP n (0.1) 15) VP TO VP (0.2) 6) NP NP PP (0.2) 16) VP v NP PP (0.1) 7) NP propn (0.1) 17) VP v PP (0.1) 8) NP NOM (0.2) 18) PPprep NP (1.0) 9) NOMadj n (1.0) 19) ADJPadj (0.5) 10) VPv (0.1) 20) ADJPadj VP (0.5) 21) TO to (1.0) A. Parsing
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The annotation of the C-ORAL-BRASIL oral through the implementation of the Palavras Parser

The annotation of the C-ORAL-BRASIL oral through the implementation of the Palavras Parser

C-ORAL-BRASIL uses a number of symbols and encoding conventions to handle data flow issues like turn taking, prosodic breaks, speaker overlap, retractions and interruptions. Such encoding is either in non-alphanumeric form (<, /, +), or not part of an utterance (speaker names), so they either cannot or must not be analyzed by the parser. To both maintain this meta-information and to provide text-only input to the parser, we opted for a two-level annotation, where meta-information is “stored” in angle brackets on separate lines as corpus meta-markup. PALAVRAS' annotation is transparent to such markup and will not change, remove or try to analyze it.
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Clause Restructuring For SMT Not Absolutely Helpful

Clause Restructuring For SMT Not Absolutely Helpful

Each experiment is paired: the reordered system reuses the recasing and language models of its cor- responding baseline system, to eliminate one source of possible variation. Training the parser with less data affects only the reordered systems; for experi- ments using these models, the corresponding base- lines (and thus the shared models) are not retrained. For each system pair, we also run the HD oracle. 4.1 System Variations

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Hardware Implementation of an XML Parser

Hardware Implementation of an XML Parser

The details in implementation of this module can be understood better by analyzing the simulation output obtained for this module shown in Figure 5.11. The ‗ac‘ flag is raised by the well-formedness stage to indicate that the contents are now ready for schema validation. The extracted attribute content needs to be checked for all the constraints that are applicable for the same based on its data-type. As explained in Section 4.2, a detailed pre-defined memory structure is used by this module to identify where exactly to look for specific information required in the 512-bits wide ‗schemaAttrConts‘ value that is received. . After identifying the correct data-type for the attribute, the other constraints are now checked one by one and applied on the contents of ‗attrValue‘ input. As shown in the waveforms, the ‗totdigitsAttr‘, ‗maxLengthAttr‘, ‗minInclusiveAttr‘ and ‗fracDigitsAttr‘ are internal registers used to perform these validations. Corresponding
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An Implementation of Combined Partial Parser and Morphosyntactic Disambiguator

An Implementation of Combined Partial Parser and Morphosyntactic Disambiguator

Following the observation that both tasks, mor- phosyntactic tagging and partial constituency pars- ing, involve similar linguistic knowledge, a for- malism for simultaneous tagging and parsing was proposed in (Przepiórkowski, 2007). This paper presents a revised version of the formalism and a simple implementation of a parser understanding rules written according to it. The input to the rules is a tokenised and morphosyntactically annotated XML text. The output contains disambiguation an- notation and two new levels of constructions: syn- tactic words and syntactic groups.

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A Review on LL (1) Parser

A Review on LL (1) Parser

In traditional Top-Down parsing approach, the parser derives all possible string that can be derived from given grammar and at the end matches each string with the one that needs to be derived. LL (1) parser constructs the table and chooses the productions from the table hence the overall process of deriving the string takes lesser time as compared to naïve top down parsing approach. It is possible to detect the error at quite early stage once the entry in the table is found empty. Hence the precise point of error can be also be known in LL(1) parser.

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A Parsing Algorithm for Unification Grammar

A Parsing Algorithm for Unification Grammar

So if a is a sentence, the parser with the ideal prediction table includes Start in drO,L, and so does the parser with the weak prediction table.[].. 7 DISCUSSION AND IMPLEMENTATION NOTE[r]

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An Efficient Implementation of the Head Corner Parser

An Efficient Implementation of the Head Corner Parser

In Section 7, I compare the head-corner parser with the other parsers implemented in the Programme for the OVIS application and show that the head-corner parser op- erates much faster th[r]

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Implementation of VRML, STL File Parser with Passive Stereo Vision

Implementation of VRML, STL File Parser with Passive Stereo Vision

are the file format used to describe shape of the 3D object. The parser program reads scene description described in inputted STL or VRML file. Display module renders the 3D scene with an inclusion of properties applying various lights, material colors, options for solid, wire frame, points and lines viewing, texture mapping, transformation, different camera views etc. The primary objective of this implementation is to provide a fully functional stereo vision system that allows them to explore datasets with less expensive resources during development.

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