Internals: Class Hierarchy in the Engine

Work in progress. Contributors: Michael Burr, Anton Leykin, (your-name-here)

Rings

In order to see some of the inheritance of types, run showStructure in M2. There may be further inheritance that is not shown. In addition, running this within debug Core will give additional structure information. To find out information about a specific ring, run <Ring name>.RawRing within debug Core.

Within the d-language, RawRing is a pointer to the struct of a ring. Within the code, sometimes RawRingOrNull is used, often for debugging purposes. RawRingOrNull allows for a null pointer for a nonexistent ring. Since exceptions can't be used between C and C++, this gives a way for error handling. For example, the function toExper(x:RawRing):Expr produces a ring while toExper(x:RawRingOrNull):Expr produces a ring or an error message. To find the toExpr options, see util.d.

For the C/C++ code, the file e/x-relem.cpp contains Ring Elements and Rings. The file e/ring.hpp has the class for Ring. Here, Rings are mutable engine objects. The way this has been coded, when converting between ring types, a cast must be used, so if a new ring type is added, the conversion has to be added to the Ring class directly.