The input file is a text file containing the settings for the RFV, in the form of parameter declarations. To declare a parameter, the parameter name needs to be input, followed by an opening bracket. Then the required arguments must be included, followed by any optional arguments that are being used. The declaration is completed by a closing bracket. The arguments of a parameter may be labels, filenames, keywords, integers, or other parameters. Some parameters may require no arguments.
The parameter names are strings that may only contain alphabet characters and the underscore character. When specified in the input file, the alphabet characters may be in either lower or upper case. For example, to specify a line of text, the RFV does not care whether the corresponding parameter is input as TEXT_LINE or text_line. Keywords are treated in the same way. Keywords however take no arguments, and as such are not followed by a pair of parentheses.
Labels are input as strings that appear within double quotation marks ("). A label may not cross multiple lines, and must have both the opening and closing double quotation marks. Any characters may be used within a quotation, except of course the double quotation mark, since the RFV would interpret this as the end of the label. If the double quotation mark is needed as part of a string token, simply use two consecutive single quotation marks. Filenames are specified in the same way as labels, using double quotation marks. If a file is not in the directory from which the RFV will be run, the directory path to that file should also be included with the filename. Integers are simply specified as a string of digits that may or may not be preceded by a minus sign.
As has been mentioned, parentheses are used to enclose the arguments of a parameter. In this respect, the parameter declarations share some resemblance to function declarations in many programming languages. The arguments of a parameter in the input file should be separated by whitespace (that is, a single space, a tab, or a newline). The input file does not require that the arguments of a parameter be separated by a comma or a semicolon, as is used in many programming languages. However, since the input file shares similarities with programming languages, all commas and semicolons that are found in the input file will be ignored, so that the RFV can still process an input file in which these characters may have been inserted out of habit.
The RFV allows for comments to be inserted into the input file. Whenever two forward slashes (//) are found on a line of the input file, the remainder of that line is ignored, allowing comments to be included in the file. (The style of the comments are similar to those used in the C++ programming language.) Note that two forward slashes will not be interpreted as beginning a comment if they are contained within the double quotation marks of a label. Parameter names, keywords, integers, commas and semicolons, will also be interpreted part of a label string if enclosed within double quotation marks.
The first parameter that must be declared within an input file is the DEFAULTS
parameter. After this has been fully defined, the input file must contain at
least one COMPONENT parameter. These parameters of course take other
parameters as arguments. For a complete list of the parameter specifications,
and where and how each parameter can be used, see
Appendix A. Section 6
also contains a tutorial in which an example input
file is generated that utilizes all of the features of the RFV.
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