static naRef f_setfld(naContext c, naRef me, int argc, naRef* args) { naRef s = argc > 0 ? args[0] : naNil(); int bit = argc > 1 ? (int)naNumValue(args[1]).num : -1; int len = argc > 2 ? (int)naNumValue(args[2]).num : -1; naRef val = argc > 3 ? naNumValue(args[3]) : naNil(); if(!argc || !MUTABLE(args[0])|| bit < 0 || len < 0 || IS_NIL(val)) naRuntimeError(c, "missing/bad argument to setfld"); setfld(c, (void*)naStr_data(s), naStr_len(s), bit, len, (unsigned int)val.num); return naNil(); }
static naRef f_read(naContext c, naRef me, int argc, naRef* args) { struct naIOGhost* g = argc > 0 ? ioghost(args[0]) : 0; naRef str = argc > 1 ? args[1] : naNil(); naRef len = argc > 2 ? naNumValue(args[2]) : naNil(); if(!g || !MUTABLE(str) || !IS_NUM(len)) naRuntimeError(c, "bad argument to read()"); if(naStr_len(str) < (int)len.num) naRuntimeError(c, "string not big enough for read"); return naNum(g->type->read(c, g->handle, naStr_data(str), (int)len.num)); }
static naRef dofld(naContext c, int argc, naRef* args, int sign) { naRef s = argc > 0 ? args[0] : naNil(); int bit = argc > 1 ? (int)naNumValue(args[1]).num : -1; int len = argc > 2 ? (int)naNumValue(args[2]).num : -1; unsigned int f; if(!naIsString(s) || !MUTABLE(args[0]) || bit < 0 || len < 0) naRuntimeError(c, "missing/bad argument to fld/sfld"); f = fld(c, (void*)naStr_data(s), naStr_len(s), bit, len); if(!sign) return naNum(f); if(f & (1 << (len-1))) f |= ~((1<<len)-1); // sign extend return naNum((signed int)f); }