'Ll 1 grammars' diaporamas de présentation

CS412/413

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Parse Trees

Parse Trees. Definitions Relationship to Left- and Rightmost Derivations Ambiguity in Grammars. Parse Trees. Parse trees are trees labeled by symbols of a particular CFG. Leaves : labeled by a terminal or ? . Interior nodes : labeled by a variable.

346 views • 32 slides

Parse Trees

Parse Trees. Definitions Relationship to Left- and Rightmost Derivations Ambiguity in Grammars. Parse Trees. Parse trees are trees labeled by symbols of a particular CFG. Leaves : labeled by a terminal or ? . Interior nodes : labeled by a variable.

329 views • 32 slides

Lecture 7 Predictive Parsing

Lecture 7 Predictive Parsing. CSCE 531 Compiler Construction. Topics Review Top Down Parsing First Follow LL (1) Table construction Readings: 4.4 Homework: Program 2. February 1, 2006. Overview. Last Time Ambiguity in classic programming language grammars Expressions

523 views • 27 slides

Ambiguity, LL1 Grammars and Table-driven Parsing

Ambiguity, LL1 Grammars and Table-driven Parsing. Problems with Grammars. Not all grammars are usable! Ambiguous Unproductive non-terminals Unreachable rules. E. E. E. E. E. *. E. +. D. E. *. E. E. +. E. D. 3. 1. D. D. D. D. 2. 3. 1. 2. Ambiguous Grammar.

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LL(1) grammars

164 views • 9 slides

Useful modifications to grammars

223 views • 8 slides

CS310

291 views • 5 slides