Hi Kashyap, > 1. About RAM vs ROM. Call me lazy but I would really appreciate a > description of how the RAM vs ROM decision is taken here (and in general > too..I mean, it is not clear to me how gen3m.c determines how something is > never written to or not) > if (x > 0) > Rom[x] = strdup(buf); > else > Ram[-x] = strdup(buf);
The sign of 'x' is determined when reading the symbol, in the functions romSym() and ramSym(). You can see where something gets stored to by whether RomIx or RamIx is used. Cell data all go to ROM, most symbol value cells to RAM (except some constants like NIL or T). This allows also symbols in ROM to be redefined at runtime. > 2. Can I try and make the CELL have an additional byte to store the TYPE > and get rid using tagged pointers? Clearly, it would be less efficient at > runtime but perhaps it would be more easy to understand. Is there any > reason that this would not work? No, this would work. You could use the most significant byte, but have to mask it when using the pointer (and live with the decreased address space size ;) ☺/ A!ex -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
