The decomposition of attribute grammars into modules is investigated. In our approach the alternative rules of a nonterminal may be separated into different modules. The aim of our concept is the generation of special grammars in respect to the design decisions of a compiler writer. Therefore, a module represents a concrete syntactic or semantic design decision~ The import-and export-interface of a module contains not only attributes of its nonterminals, but also semantic functions and

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... ions of the syntax tree. In the module body the syntactic as well as the semantic rules are arranged. The set of already implemented modules can be reused for new applications. A short explanation of these ideas within the system FLR is given.