Show (as “circles-and-arrows” diagrams) the finite automata for Exercise 2.1.

Data from Exercise 2.1:

Write regular expressions to capture the following.

(a) Strings in C. These are delimited by double quotes ("), and may not contain newline characters. They may contain double-quote or backslash characters if and only if those characters are “escaped” by a preceding backslash. You may find it helpful to introduce shorthand notation to represent any character that is not a member of a small specified set.

(b) Comments in Pascal. These are delimited by (* and *) or by { and }. They are not permitted to nest.

(c) Numeric constants in C. These are octal, decimal, or hexadecimal integers, or decimal or hexadecimal floating-point values. An octal integer begins with 0, and may contain only the digits 0–7. A hexadecimal integer begins with 0x or 0X, and may contain the digits 0–9 and a/A–f/F. A decimal floating-point value has a fractional portion (beginning with a dot) or an exponent (beginning with E or e). Unlike a decimal integer, it is allowed to start with 0. A hexadecimal floating point value has an optional fractional portion and a mandatory exponent (beginning with P or p). In either decimal or hexadecimal, there may be digits to the left of the dot, the right of the dot, or both, and the exponent itself is given in decimal, with an optional leading + or - sign. An integer may end with an optional U or u (indicating “unsigned”), and/or L or l (indicating “long”) or LL or ll (indicating “long long”). A floating-point value may end with an optional F or f (indicating “float”—single precision) or L or l (indicating “long”—double precision).

(d) Floating-point constants in Ada. These match the definition of real in Example 2.3, except that (1) a digit is required on both sides of the decimal point, (2) an underscore is permitted between digits, and (3) an alternative numeric base may be specified by surrounding the non exponent part of the number with pound signs, preceded by a base in decimal (e.g., 16#6.a7#e+2). In this latter case, the letters a . . f (both upper- and lowercase) are permitted as digits. Use of these letters in an inappropriate (e.g., decimal) number is an error, but need not be caught by the scanner.