1 files changed, 96 insertions, 0 deletions
diff --git a/sam/list.c b/sam/list.c
new file mode 100644
index 0000000..d2e5d2d
--- /dev/null
+++ b/sam/list.c
@@ -0,0 +1,96 @@
+#include "sam.h"
+
+/*
+ * Check that list has room for one more element.
+ */
+static void
+growlist(List *l, int esize)
+{
+	uchar *p;
+
+	if(l->listptr == nil || l->nalloc == 0){
+		l->nalloc = INCR;
+		l->listptr = emalloc(INCR*esize);
+		l->nused = 0;
+	}
+	else if(l->nused == l->nalloc){
+		p = erealloc(l->listptr, (l->nalloc+INCR)*esize);
+		l->listptr = p;
+		memset(p+l->nalloc*esize, 0, INCR*esize);
+		l->nalloc += INCR;
+	}
+}
+
+/*
+ * Remove the ith element from the list
+ */
+void
+dellist(List *l, int i)
+{
+	Posn *pp;
+	void **vpp;
+
+	l->nused--;
+
+	switch(l->type){
+	case 'P':
+		pp = l->posnptr+i;
+		memmove(pp, pp+1, (l->nused-i)*sizeof(*pp));
+		break;
+	case 'p':
+		vpp = l->voidpptr+i;
+		memmove(vpp, vpp+1, (l->nused-i)*sizeof(*vpp));
+		break;
+	}
+}
+
+/*
+ * Add a new element, whose position is i, to the list
+ */
+void
+inslist(List *l, int i, ...)
+{
+	Posn *pp;
+	void **vpp;
+	va_list list;
+
+
+	va_start(list, i);
+	switch(l->type){
+	case 'P':
+		growlist(l, sizeof(*pp));
+		pp = l->posnptr+i;
+		memmove(pp+1, pp, (l->nused-i)*sizeof(*pp));
+		*pp = va_arg(list, Posn);
+		break;
+	case 'p':
+		growlist(l, sizeof(*vpp));
+		vpp = l->voidpptr+i;
+		memmove(vpp+1, vpp, (l->nused-i)*sizeof(*vpp));
+		*vpp = va_arg(list, void*);
+		break;
+	}
+	va_end(list);
+
+	l->nused++;
+}
+
+void
+listfree(List *l)
+{
+	free(l->listptr);
+	free(l);
+}
+
+List*
+listalloc(int type)
+{
+	List *l;
+
+	l = emalloc(sizeof(List));
+	l->type = type;
+	l->nalloc = 0;
+	l->nused = 0;
+
+	return l;
+}