Hi.
Removes Symbol>>hash. This is done since now symbols may be equal to strings and viceversa. When they were equal, though, their hashes were not and that's not good.
Fixing this brought up some issues with the Interpreter. When the C code is generated, some methods are inlined. Such inlined methods have local variable names that mask global variable names. There is a check for this (CCodeGenerator>>prepareMethods). The methods dictionary had symbol keys, but it was queried for strings. Since the hashes for equal variable names were different, those overlapping names were never reported as errors by the CCodeGenerator. We changed the names of the local variables by prefixing them with 'local'.
Also removes String>>hash. The previous implementations could provide only 14 bits of hash, and this was just at its best. It did not spread hash values enough either, so just about 12 bits were being used by all the Strings in the system. The new implementation of hash for Strings provides an excellent hash mentioned by Mark van Gulik, and it is now used in more places through the Collection hierarchy (check ByteArray>>hash, SequenceableCollection>>hash and Collection>>hash).
Also reimplements Fraction>>hash so that it does not answer LargeIntegers. A small method called hashMultiply was added to SmallInteger to keep things clean. A convenient method was also added to Set class to rehash all sets except MethodDictionaries (takes too long and they are not affected by #hash).
Finally, do not edit or fileOut this changeset! It contains hand made postscripts and initialization code that will rehash all Sets and Dictionaries in your system.
A quick check to see if this changeset did its work properly is to do the following: * Try to get the Set class by typing 'Set' in a workspace and then doing a print-it * Open a workspace
If that works, you are in good shape.
Andres.
PS: Needless to say, this changeset has been tested :)))...