Extended Input and Output Stream Classes

The pt_ofstream class is used in the SDF primitive Printer. Include the header file pt_fstream.h. The pt_ofstream constructor is invoked in the setup method with the call to new. It would not work to invoke it in the constructor for the primitive, since the fileName parameter would not have been initialized. Notice that the setup method reclaims the memory allocated in previous runs (or previous invocations of the setup method) before creating a new pt_ofstream object. Notice that we are not using a wrapup method to reclaim the memory, since this method is not invoked if an error occurs during a run.

The classes pt_ifstream and pt_ofstream are only a slight extension of the C++ standard classes ifstream and ofstream. They add the following features:

• First, certain special filenames are recognized as arguments to the constructor or to the open method. These filenames are <cin>, <cout>, <cerr> or <clog> (the angle brackets must be part of the string), then the corresponding standard stream of the same name is used for input (pt_ifstream) or output (pt_ofstream). Users accustomed to C standard I/O can alternatively use <stdin>, <stdout> or <stderr>.
• Second, the MLDesigner expandPathName is applied to the filename before it is opened, permitting it to start with ~user or $VAR
• Finally, if a failure occurs when the file is opened, Error::abortRun is called with an appropriate error message.

These classes can be used for binary character data as well as ASCII.