Concepts of Programming Languages

180 Chapter 4 Lexical and Syntax Analysis 4.3.3 Bottom-Up Parsers A bottom-up parser constructs a parse tree by beginning at the ...

4.4 Recursive-Descent Parsing 181 the parsing process. Backing up the parser also requires that part of the parse tree being con ...

182 Chapter 4 Lexical and Syntax Analysis out the parse tree that can be rooted at that nonterminal and whose leaves match the i ...

4.4 Recursive-Descent Parsing 183 Notice that the expr function includes tracing output statements, which are included to produc ...

184 Chapter 4 Lexical and Syntax Analysis produced when an error is detected. Furthermore, parsers must recover from the error s ...

4.4 Recursive-Descent Parsing 185 Figure 4.2 Parse tree for (sum+ 47 ) / total ()/sum total 47 <factor> <term> <e ...

186 Chapter 4 Lexical and Syntax Analysis One more example grammar rule and parsing function should help solidify the reader’s u ...

4.4 Recursive-Descent Parsing 187 language. The characteristics of a grammar that allows a recursive-descent parser to be built ...

188 Chapter 4 Lexical and Syntax Analysis Because there is no left recursion in the F-rules, they remain the same, so the comple ...

4.4 Recursive-Descent Parsing 189 The pairwise disjointness test is as follows: For each nonterminal, A, in the grammar that has ...

190 Chapter 4 Lexical and Syntax Analysis It is not difficult to see that together, these two rules generate the same lan- guage ...

4.5 Bottom-Up Parsing 191 The underlined part of each sentential form in this derivation is the RHS that is rewritten as its cor ...

192 Chapter 4 Lexical and Syntax Analysis root nonterminal node. In terms of a parse tree, a phrase can be derived from a single ...

4.5 Bottom-Up Parsing 193 bottom-up parser is the stream of tokens of a program and the output is a sequence of grammar rules. T ...

194 Chapter 4 Lexical and Syntax Analysis This is not a serious disadvantage, however, for there are several programs available ...

4.5 Bottom-Up Parsing 195 An LR parsing table has two parts, named ACTION and GOTO. The ACTION part of the table specifies most ...

196 Chapter 4 Lexical and Syntax Analysis The parser actions are informally defined as follows: The Shift process is simple: Th ...

Summary 197 represents state 0 of the parser. The input contains the input string with an end marker, in this case a dollar sign ...

198 Chapter 4 Lexical and Syntax Analysis A lexical analyzer is a pattern matcher that isolates the small-scale parts of a progr ...

Review Questions 199 basis for recognizing a handle. A bottom-up parser is a shift-reduce algorithm, because in most cases it ei ...