CST 8152 - Midterm #2 Review Questions

• What is an ambiguous grammar? Show that a grammar is ambiguous. (2.2)
• Write a set of grammar productions that correctly parse a given language.
• Write a set of recursive-descent parsing functions for a given grammar.
• List and describe various types of error recovery in a Parser (4.1)
• Write a function that implements panic mode error recovery in a language that uses ';' to separate statements.
• What are Aho's three goals of an error handler in a parser? (4.1)
• Of what use are reserved words to a predictive parser?
• What are the four components of a Context Free Grammar? (2.2)
• Show how parse trees for left- and right-associative grammars differ. (2.2)
• Write a parse tree for a given sentence and grammar.
• What is a parse tree? (2.2)
• Why not use a CFG to define the lexical syntax of a language, instead of using regular expressions? (4.3)
• Describe some methods of error repair and recovery.
• Describe four error recovery strategies. (4.2)

Text Readings up to Midterm #2

• Aho sections 2.1, 2.2: parsing, syntax definition, context free grammars, parse trees, ambiguity, associativity, precedence
• 2.4: top-down parsing, predictive parsing, function of lookahead, FIRST sets, designing a predictive parser
• Recursive Descent parsing functions: Fig 2.24, 2.27, 2.28
• Matching statements by using reserved words: Fig 2.34
• 4.1: role of the parser, error recovery, nature of syntax errors
• Parts of section 4.2: Context Free Grammars, terminology and notation, ambiguity
• Parts of section 4.3: how are grammars built?
• Parts of section 4.4: recursive-descent parsing, predictive parsers, transition diagrams
• Error handling: Aho p. 11 and section 4.1

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