Autor(es):
Oliveira, Nuno 
; Henriques, Pedro ; Cruz, Daniela ; Pereira, Maria João
Data: 2009
Identificador Persistente: http://hdl.handle.net/10198/1190
Origem: Biblioteca Digital do IPB
Assunto(s): Gramáticas de atributos; XML
Descrição
Attribute Grammars (AG) are a powerful and well-known formalism used to create language processors. The meta-language used to write an AG (to specify a language and its processor) depends on the compiler generator tool chosen. This fact can be an handicap when it is necessary to share or transfer information between language-based systems; this is, we face an interchangeability
problem, if we want to reuse the same language specification (the AG) on another
development environment.
To overcome this interoperability flaw, we present in this paper XAGra - an XML dialect to describe attribute grammars. XAGra was precisely conceived aiming at adapting the output of a visual attribute grammar editor (named VisualLISA) to any compiler generator tool.
Based on the formal definition of Attribute Grammar and on the usual requirements
for the generation of a language processor, XAGra schema is divided into five main fragments: symbol declarations, attribute declarations, semantic productions (including attribute evaluation rules, contextual conditions, and translation
rules), import, and auxiliary functions definitions. In the paper we present those components, but the focus will be on the systematic way we followed to design the XML schema based on the formal definition of AG.
To strength the usefulness of XAGra as a universal AG specification, we show at a
glance XAGraAl, a tool taking as input an AG written in XAGra, is a Grammar Analyzer and Transformation system that computes dependencies among symbols, various metrics, slices and rebuilds the grammar.
