1 files changed, 26 insertions, 0 deletions
diff --git a/push.c b/push.c
new file mode 100644
index 0000000..d31de5e
--- /dev/null
+++ b/push.c
@@ -0,0 +1,26 @@
+#include "prv.h"
+#include <stdlib.h>
+
+int push(const struct pos *pos, struct prv *p)
+{
+    size_t n = p->n + 1;
+    struct pos *npos = realloc(p->pos, n * sizeof *npos);
+
+    if (!npos)
+    {
+        perror("realloc(3)");
+        return -1;
+    }
+    else if (p->n)
+    {
+        struct pos *prev = &npos[p->n - 1];
+
+        prev->seq = prev->stseq;
+        prev->step = prev->seq->steps;
+        p->i++;
+    }
+
+    npos[p->n++] = *pos;
+    p->pos = npos;
+    return 0;
+}