PPT-Attribute Grammars

Prabhaker Mateti ACK Assembled from many sources About Attribute Grammars Attribute grammars AGs add semantic info on parse tree nodes Used for semantic checking and other compiletime analyses eg type checking in a compiler. Krishnaprasad Thirunarayan Metadata and Languages Laboratory Department of Computer Science and Engineering BACKGROUND Let G = (N, T, P, S) be a context-free grammar for a language L (Aho et t of Ehsan. . Khoddammohammadi. Recent Advances in Parsing Technology. WS 2012/13. Saarland University. 1. Outline. Definition and motivation behind . u. nsupervised . g. rammar learning. Non-parametric Bayesian statistics. The Chomsky hierarchy of grammars . Context-free grammars describe languages that regular grammars can’t . Unrestricted. Context-sensitive. Context-free. Regular. Slide after Durbin, . et al. ., 1998. A . shorted version from. :. Anastasia . Berdnikova. &. Denis . Miretskiy. ‘Colourless green ideas sleep furiously’.. Chomsky constructed finite formal machines – ‘. grammars. ’.. ‘Does the language contain this sentence?’ (intractable) . David Kauchak. CS30 – Spring 2016. Grammars. What is a grammar?. Grammars. Language view: . A grammar is a set of structural rules that govern the composition of sentences, phrases and words.. Computational view:. Attributes store extra . information. in . AST nodes.. type: . int. val. : . 3. code: . iconst_3. .... type: . int. val. : 4. code: . iconst_4. .... type: . int. val. : 4. env. : •. offs: 1. code: . Ravichandhran. . Madhavan. , . EPFL. Joint work with. Mikael . Mayër. , EPFL. Sumit. . Gulwani. , MSR. Viktor . Kuncak. , EPFL. Overview. u. nit -> . pkg. ? . i. mp* type*. field -> method | . Cradle. -to-Cradle . Design. . Douglas H. Fisher . Vanderbilt University. douglas.h.fisher@. vanderbilt.edu. Mary Lou Maher . University of Maryland, College Park. marylou.maher@. gmail.com. Presentation to the . David Kauchak. CS30 – Spring 2016. Grammars. What is a grammar?. Grammars. Language view: . A grammar is a set of structural rules that govern the composition of sentences, phrases and words.. Computational view:. Attributes can have any type, but often they are trees. Example:. context-free grammar rule: . A ::= B C. attribute grammar rules:. A ::= B C . { . Plus($1. , $. 2. ) . }. or, . e.g.. A ::= B. Learning . Objectives. At the conclusion of the chapter, the student will be able to:. Define the three basic concepts in the theory of computation: automaton, formal language, and grammar.. Solve exercises using mathematical techniques and notation learned in previous courses.. Review. So far, we’ve covered the following: . . Compilation methods: compilation vs. interpretation.. . The overall . c. ompilation process.. Front-end analysis . Lexical Analysis. Syntax Analysis. Chapter 3 Topics. Introduction. The General Problem of Describing Syntax. Formal Methods of Describing Syntax. Attribute Grammars. Describing . the Meanings of Programs: Dynamic Semantics. 1-. 2. Introduction. Eran. . Yahav. 1. 2. You are here. Executable . code. exe. Source. text . txt. Compiler. Lexical. Analysis. Syntax Analysis. Parsing. Semantic. Analysis. Inter.. Rep.. (IR). Code. Gen.. Last Week: Types.