In many instances it is desirable to be able to read and write information in CIF format without the overhead of dictionary based integrity processing. The CIFPARSE function library was developed to provide convenient tools to access CIF data without any semantic checking (Figure 8). CIFPARSE uses a simple lex/yacc parser to read and check the syntax of mmCIF data files. CIF data is stored as strings in a simple data structure and a collection of access functions are provided to retrieve individual items of data.
This library is particularly useful for applications that exchange CIF data between program applications or for repetitive access to static CIF data that has been previously semantically validated. A reference manual which describes each function in detail is available [15].
Figure 8:
Functional diagram of the CIFPARSE function library illustrating the intended
use of the library for processing mmCIF data files.