String conversion

Two procedures are provided to simplify reading data retreved from XML documents into Fortran variables. The subroutine rts performs the data conversion step and the function countrts can be used to allocate an array of the correct size for the incomming data.

rts subroutine

The rts subroutine can be imported from FoX_common. In its simplest form, it is called in this fashion:

call rts(string, data)

string is a simple Fortran string (probably retrieved from an XML file.)

data is any native Fortran datatype: logical, character, integer, real, double precision, complex, double complex, and may be a scalar, 1D or 2D array.

rts will attempt to parse the contents of string into the appropriate datatype, and return the value in data.

Additional information or error handling is accomplished with the following optional arguments:

num

num is an integer; on returning from the function it indicates the number of data items read before either:

• an error occurred
• the string was exhausted of data items
• data was filled.

iostat

iostat is an integer, which on return from the function has the values:

• 0 for no problems
• -1 if too few elements were found in string to fill up data
• 1 if data was filled, but there were still data items left in string
• 2 if the characters found in string could not be converted to the appropriate type for data.

NB if iostat is not specified, and a non-zero value is returned, then the program will stop with an error message.

String formatting

When string is expected to be an array of strings, the following options are used to break string into its constituent elements:

• By default it is assumed that the elements are separated by whitespace, and that multiple whitespace characters are not significant. No zero-length elements are possible, nor are elements containing whitespace.

• An optional argument, separator may be specified, which is a single character. In this case, each element consists of all characters between subsequent occurences of the separator. Zero-length elements are possible, but no escaping mechanism is possible.

• Alternatively, an optional logical argument csv may be specified. In this case, the value of delimiter is ignored, and the string is parsed as a Comma-Separated-Value string, according to RFC 4180.

Numerical formatting.

Numbers are expected to be formatted according to the usual conventions for Fortran input.

Complex number formatting.

Complex numbers may be formatted according to either normal Fortran conventions (comma-separated pairs) or CMLComp conventions

Logical variable formatting.

Logical variables must be encoded according to the conventions of XML Schema Datatypes - that is, True may be written as "true" or "1", and False may be written as "false" or "0".

countrts function

The countrts function can also be imported from FoX_common. In its simplest form, it is called in this fashion:

countrts(string, datatype)

string is a simple Fortran string (probably retrived from an XML file)

datatype is a scalar argument of any native Fortran datatype (logical, character, integer, real, double precision, complex or double complex).

The function returns a default integer equal to the number of elements that rts would return if called with a sufficently large array of the same type as datatype. countrts returns 0 to indicate that characters were found in the string that could not be converted. If datatype is a character, the optional arguments seperator and csv are avalable as described in "string formatting" above. The countrts function is pure and can be used as a specification function.