Efficient recursive backup parsing
نویسنده
چکیده
There are several ways to create an exact recognizer for the language defined by a context free grammar. The recursive backup technique, proposed by [Kos75], is capable of handling (locally) ambiguous grammars. Due to its structure, it is not limited to context free grammars, but applicable for affix grammars in general. This paper shows that ‘tactful’ recursive backup parsing can be efficient, in spite of its worst case exponential time complexity. This ‘tact’ however, should not be supplied by the grammar writer, but automatically deduced by a parser generator. In this paper we will discuss the deduction process for a simple form of two-level grammars: Affix Grammars over Finite Lattices (AGFLs), a formalism to express the syntax of natural languages.
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