The INPUT class library[ Home Page ] [ Eiffel Archive ] [ Eiffel Classes and Clusters ]
The INPUT class libraryWritten by Kane Marshall (kanemars@yahoo.co.uk).
kane.zip (7639 bytes)
This class library provides safe command line input routines. It has been implemented in TowerEiffel 2.0, and can easily be implemented in other versions of Eiffel. This class library is released to the public domain.
The routines of class INPUT that get information from the command line ensure that the text entered is in the correct format, otherwise a `follow_up_prompt' will repeatedly be displayed until an acceptable string is entered. The `follow_up_prompt' can be set with the procedure `set_follow_up_prompt'. A default `follow_up_prompt' setting will always be used.
Procedure `get_non_empty_string' ensures a string of at least one non whitespace character is entered. An example of its use is:
local
in: INPUT
do
!! in
in.put_string ("Enter your name: ")
in.get_non_empty_string
Procedure `get_formatted_string' ensures a string satisfies the rules provided by a FORMAT_TEST object (described next).
FORMAT_TEST is a supporting class of INPUT of which the deferred feature `is_correct_format' ensures that an entered string is of the correct format. Each descendant of FORMAT_TEST has to define a `default_follow_up_prompt'.
One such descendant of FORMAT_TEST is OPTIONS, which ensures the string entered is a printable representation (`out') of one of a selection of specified objects. An example of its use is:
local
in: INPUT
rules: FORMAT_TEST
do
!! in
!OPTIONS! rules.make (<<0, 1, "more", 'm'>>)
in.put_string ("How many siblings do you have (0, 1 or more)?")
in.get_formatted_string (rules)
The example class DDMMYYY_TEST ensures that a string entered is in dd/mm/yyyy format.
The deferred generic class RANGE ensures that the string entered is of a correct format and also within a specified range of two values `lower' and `upper'. Example descendants of this class are INTEGER_RANGE and DATE_RANGE, whose names are self explanatory.
IO_TESTER is a root class which tests the features of the INPUT class library. Example output from this running system is stored in file `out.exp'.
[ Home Page ] [ Eiffel Archive ] [ Eiffel Classes and Clusters ]