Generating Software from Specifications WS 2013/14 - Solution 3

Solution for Exercise 6

The specification file TryScanSol.fw contains the commented solution of this exercise. Here are a few remarks on it:

The number of given test cases is to be considered as an absolute minimum! Some students are observed to check an unacceptable small number of test cases.

Be aware that canned token descriptions include the association of a useful coding function, which is implemented in a library of Eli.

Be aware that comments are not considered to be tokens. They may occur before or after any token in the program. Hence, they do not occur in the concrete syntax, and they are not named in the token specification.

The description of line comments of Java is eaysily obtained by copying that of Ada line comments, and replacing the -- by //, where the / characters have to be escaped.

Solution for Exercise 7

The directory blatt3/solution contains the commented solution of this exercise in the file CalendarSol7.fw.

Solution for Exercise 8

The solution in File CalendarSol8.fw continues that of the previous exercise.

Define DayNames using an EBNF construct.
The production

  DayNames:       DayName / DayNames ',' DayName.

is substituted by

  DayNames:       DayName // ','.

Modify the structure of Entry such that the time or the time span is not combined with the Description, but with the Date.
The productions

  Entry:          Date Event.
  Event:          When Description / Description.

are substituted by

  Entry:          DateAndTime Description.
  DateAndTime:	  Date When.

Modify the structure of Entry such that Date, time or time span, and Description are direct components of Entry.
The production for Entry is changed into
```
  Entry:	Date When Description.
  When:         Time / Time '-' Time / .
```
The productions for Event and DateAndTime are eliminated.
Simplify the productions for patterns of dates: Specify Modifier to be optional; then remove unnecessary productions.
The productions for patterns are substituted by
```
  GeneralPattern:	SimplePattern Modifier.
  SimplePattern:	'Weekday' / 'Weekend'.
  Modifier:             '+' DayNames / '-' DayNames / .
```
Finally extend the language such that also spans of dates can be described, like "20.8. - 5.9." or "Tue-Thu" but not "Tue-4.5.".
Two more alternatives are inserted for Date:
```
  Date:	DayNum '.' MonNum '.' '-' DayNum '.' MonNum '.' /
	DayName '-' DayName.
```

Generiert mit Camelot | Probleme mit Camelot? | Geändert am: 13.11.2013

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