Compiler design problem, This is done by changing the CFG

Compiler design problem

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Reference no: EM13336574

Compiler Design

Q1. Sometimes it is necessary to modify the syntax of a programming language. This is done by changing the CFG that the language uses. What changes would have to be made to ac's CFG (Figure) to implement the following changes?

29_Compiler Design.png

(a) All ac programs must contain at least one statement.
(b) All integer declarations must precede all float declarations.
(c) The first statement in any ac program must be an assignment statement.

Q2. Extend the ac scanner (Figure) in the following ways:

801_Compiler Design1.png

(a) A floatdcl can be represented as either f or float, allowing a more Java-like syntax for declarations.
(b) A intdcl can be represented as eitheri or int.
(c) A num may be entered in exponential (scientific) form. That is, an ac num may be suffixed with an optionally signed exponent (1.0e10, 123e-22 or 0.31415926535e1).

Q3. Figure scans an input stream for an inum or fnum based on the regular expressions for those patterns shown in Figure. The code in Figure does not check for errors.

465_Compiler Design2.png

(a) Where could errors occur in Figure?
(b) For each error, what action would you take should the error occur?

Reference no: EM13336574

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