73 lines
1.4 KiB
C
73 lines
1.4 KiB
C
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/* $Revision: 1.5 $
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*/
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/* Functions that maintain a properly GC-linked list of Scheme
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* arguments. The parser collects arguments to an event procedure
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* using args_add(); the code that eventually calls the event
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* procedure calls args_get() to obtain a list of arguments that
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* can directly be passed to Funcall().
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*
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* args_clear() -- clears the list
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* args_add(obj) -- appends an object to the list
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* args_get() -- returns the list
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* args_num() -- returns the current length of the list
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*/
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#include "unroff.h"
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static Object args, last, rest;
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static int num;
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void args_clear(void) {
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if (Nullp(last)) {
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if (!Nullp(rest))
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args = rest;
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} else
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P_Setcdr(last, rest);
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last = Null;
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num = 0;
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}
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void args_add(Object x) {
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Object tmp;
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GC_Node;
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if (Nullp(last)) {
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last = args;
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} else {
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if (Nullp(Cdr(last))) {
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GC_Link(x);
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tmp = Cons(False, Null);
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GC_Unlink;
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Cdr(last) = tmp;
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}
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last = Cdr(last);
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}
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Car(last) = x;
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rest = Cdr(last);
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num++;
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}
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Object args_get(void) {
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if (Nullp(last)) {
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rest = args;
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return Null;
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}
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rest = Cdr(last);
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P_Setcdr(last, Null);
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return args;
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}
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int args_num(void) {
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return num;
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}
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void init_args(void) {
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rest = Cons(False, Null);
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args = last = Null;
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Global_GC_Link(args);
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Global_GC_Link(last);
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Global_GC_Link(rest);
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}
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