"GMACROS for
The Zork Trilogy
(c) Copyright 1983 Infocom, Inc. All Rights Reserved"
<SETG C-ENABLED? 0>
<SETG C-ENABLED 1>
<SETG C-DISABLED 0>
<DEFMAC TELL ("ARGS" A)
<FORM PROG ()
!<MAPF ,LIST
<FUNCTION ("AUX" E P O)
<COND (<EMPTY? .A> <MAPSTOP>)
(<SET E <NTH .A 1>>
<SET A <REST .A>>)>
<COND (<TYPE? .E ATOM>
<COND (<OR <=? <SET P <SPNAME .E>>
"CRLF">
<=? .P "CR">>
<MAPRET '<CRLF>>)
(<EMPTY? .A>
<ERROR INDICATOR-AT-END? .E>)
(ELSE
<SET O <NTH .A 1>>
<SET A <REST .A>>
<COND (<OR <=? <SET P <SPNAME .E>>
"DESC">
<=? .P "D">
<=? .P "OBJ">
<=? .P "O">>
<MAPRET <FORM PRINTD .O>>)
(<OR <=? .P "A">
<=? .P "AN">>
<MAPRET <FORM PRINTA .O>>)
(<OR <=? .P "NUM">
<=? .P "N">>
<MAPRET <FORM PRINTN .O>>)
(<OR <=? .P "CHAR">
<=? .P "CHR">
<=? .P "C">>
<MAPRET <FORM PRINTC .O>>)
(ELSE
<MAPRET
<FORM PRINT
<FORM GETP .O .E>>>)>)>)
(<TYPE? .E STRING ZSTRING>
<MAPRET <FORM PRINTI .E>>)
(<TYPE? .E FORM LVAL GVAL>
<MAPRET <FORM PRINT .E>>)
(ELSE <ERROR UNKNOWN-TYPE .E>)>>>>>
<ROUTINE PRINTA (O)
<TELL "a " D .O>>
<DEFMAC VERB? ("ARGS" ATMS)
<MULTIFROB PRSA .ATMS>>
<DEFMAC PRSO? ("ARGS" ATMS)
<MULTIFROB PRSO .ATMS>>
<DEFMAC PRSI? ("ARGS" ATMS)
<MULTIFROB PRSI .ATMS>>
<DEFMAC ROOM? ("ARGS" ATMS)
<MULTIFROB HERE .ATMS>>
<ZSTR-OFF>
<DEFINE MULTIFROB (X ATMS "AUX" (OO (OR)) (O .OO) (L ()) ATM)
<REPEAT ()
<COND (<EMPTY? .ATMS>
<RETURN!- <COND (<LENGTH? .OO 1> <ERROR .X>)
(<LENGTH? .OO 2> <NTH .OO 2>)
(ELSE <CHTYPE .OO FORM>)>>)>
<REPEAT ()
<COND (<EMPTY? .ATMS> <RETURN!->)>
<SET ATM <NTH .ATMS 1>>
<SET L
(<COND (<TYPE? .ATM ATOM>
<FORM GVAL
<COND (<==? .X PRSA>
<PARSE
<STRING "V?"
<SPNAME .ATM>>>)
(ELSE .ATM)>>)
(ELSE .ATM)>
!.L)>
<SET ATMS <REST .ATMS>>
<COND (<==? <LENGTH .L> 3> <RETURN!->)>>
<SET O <REST <PUTREST .O (<FORM EQUAL? <FORM GVAL .X> !.L>)>>>
<SET L ()>>>
<DEFMAC BSET ('OBJ "ARGS" BITS)
<MULTIBITS FSET .OBJ .BITS>>
<DEFMAC BCLEAR ('OBJ "ARGS" BITS)
<MULTIBITS FCLEAR .OBJ .BITS>>
<DEFMAC BSET? ('OBJ "ARGS" BITS)
<MULTIBITS FSET? .OBJ .BITS>>
<DEFINE MULTIBITS (X OBJ ATMS "AUX" (O ()) ATM)
<REPEAT ()
<COND (<EMPTY? .ATMS>
<RETURN!- <COND (<LENGTH? .O 1> <NTH .O 1>)
(<==? .X FSET?> <FORM OR !.O>)
(ELSE <FORM PROG () !.O>)>>)>
<SET ATM <NTH .ATMS 1>>
<SET ATMS <REST .ATMS>>
<SET O
(<FORM .X
.OBJ
<COND (<TYPE? .ATM FORM> .ATM)
(ELSE <FORM GVAL .ATM>)>>
!.O)>>>
<ZSTR-ON>
<DEFMAC RFATAL ()
'<PROG () <PUSH 2> <RSTACK>>>
The PROB macro can be called two ways. <PROB 50> has a straight 50% chance of success. (Or actually 49% – there’s an off-by-one bug! But let that slide.)
<PROB 50 T> invokes ZPROB, which reduces your chance of success if you are not LUCKY. See here for an example.
However, a few places in the code call PROB with two numbers. (See here, here, here.) This usage is left over from MIT Zork; the second number is supposed to be the un-LUCKY chance. But in this version, it is ignored! The code just follows the "divide by three" logic of ZPROB. This leads to some probability bugs.
(contrib: Monica Morse)
<COND (<ASSIGNED? LOSER?> <FORM ZPROB .BASE?>)
(ELSE <FORM G? .BASE? '<RANDOM 100>>)>>
This is a tweaked random die roll. Normally, it succeeds at a rate of BASE out of 100. But if you are not LUCKY, it’s BASE out of 300 – effectively dividing your chance of success by three.
(BASE)
<COND (,LUCKY <G? .BASE <RANDOM 100>>)
(ELSE <G? .BASE <RANDOM 300>>)>>
<ROUTINE RANDOM-ELEMENT (FROB)
<GET .FROB <RANDOM <GET .FROB 0>>>>
<ROUTINE PICK-ONE (FROB
"AUX" (L <GET .FROB 0>) (CNT <GET .FROB 1>) RND MSG RFROB)
<SET L <- .L 1>>
<SET FROB <REST .FROB 2>>
<SET RFROB <REST .FROB <* .CNT 2>>>
<SET RND <RANDOM <- .L .CNT>>>
<SET MSG <GET .RFROB .RND>>
<PUT .RFROB .RND <GET .RFROB 1>>
<PUT .RFROB 1 .MSG>
<SET CNT <+ .CNT 1>>
<COND (<==? .CNT .L> <SET CNT 0>)>
<PUT .FROB 0 .CNT>
.MSG>
<DEFMAC ENABLE ('INT) <FORM PUT .INT ,C-ENABLED? 1>>
<DEFMAC DISABLE ('INT) <FORM PUT .INT ,C-ENABLED? 0>>
<DEFMAC FLAMING? ('OBJ)
<FORM AND <FORM FSET? .OBJ ',FLAMEBIT>
<FORM FSET? .OBJ ',ONBIT>>>
<DEFMAC OPENABLE? ('OBJ)
<FORM OR <FORM FSET? .OBJ ',DOORBIT>
<FORM FSET? .OBJ ',CONTBIT>>>
<DEFMAC ABS ('NUM)
<FORM COND (<FORM L? .NUM 0> <FORM - 0 .NUM>)
(T .NUM)>>