System Functions

(load <fname> &key :verbose :print)  LOAD A SOURCE FILE
    <fname>     the filename string or symbol
    :verbose    the verbose flag (default is t)
    :print      the print flag (default is nil)
    returns     the filename

(save <fname>) SAVE WORKSPACE TO A FILE
    <fname>     the filename string or symbol
    returns     t if workspace was written, nil otherwise

(restore <fname>) RESTORE WORKSPACE FROM A FILE
    <fname>     the filename string or symbol
    returns     nil on failure, otherwise never returns

(dribble [<fname>])  CREATE A FILE WITH A TRANSCRIPT OF A SESSION
    <fname>     file name string or symbol
                (if missing, close current transcript)
    returns     t if the transcript is opened, nil if it is closed

(gc)  FORCE GARBAGE COLLECTION
    returns     nil

(expand <num>)  EXPAND MEMORY BY ADDING SEGMENTS
    <num>       the number of segments to add
    returns     the number of segments added

(alloc <num>)  CHANGE NUMBER OF NODES TO ALLOCATE IN EACH SEGMENT
    <num>       the number of nodes to allocate
    returns     the old number of nodes to allocate

(room)  SHOW MEMORY ALLOCATION STATISTICS
    returns     nil

(type-of <expr>)  RETURNS THE TYPE OF THE EXPRESSION
    <expr>      the expression to return the type of
    returns     nil if the value is nil otherwise one of the symbols:
                  SYMBOL          for symbols
                  OBJECT          for objects
                  CONS            for conses
                  SUBR            for built-in functions
                  FSUBR           for special forms
                  CLOSURE         for defined functions
                  STRING          for strings
                  FIXNUM          for integers
                  FLONUM          for floating point numbers
                  CHARACTER       for characters
                  FILE-STREAM     for file pointers
                  UNNAMED-STREAM  for unnamed streams
                  ARRAY           for arrays

(peek <addrs>)  PEEK AT A LOCATION IN MEMORY
    <addrs>     the address to peek at (integer)
    returns     the value at the specified address (integer)

(poke <addrs> <value>)  POKE A VALUE INTO MEMORY
    <addrs>     the address to poke (integer)
    <value>     the value to poke into the address (integer)
    returns     the value

(address-of <expr>)  GET THE ADDRESS OF AN XLISP NODE
    <expr>      the node
    returns     the address of the node (integer)

(exit)  EXIT XLISP
    returns     never returns