Added first cut of reader and writer, but nothing working at this stage.

src/conspage.h

@@ -9,14 +9,14 @@
  * the size which, by version 1, it will default to) is the maximum value of an unsigned 32
  * bit integer, which is to say 4294967296. However, we'll start small.
  */
-#define CONSPAGESIZE 256
+#define CONSPAGESIZE 64
 
 /**
  * the number of cons pages we will initially allow for. For convenience we'll set up an array
  * of cons pages this big; however, later we will want a mechanism for this to be able to grow
  * dynamically to the maximum we can currently allow, which is 4294967296.
  */
-#define NCONSPAGES 256
+#define NCONSPAGES 64
 
 /**
  * a cons page is essentially just an array of cons space objects. It might later have a local
@@ -28,9 +28,45 @@ struct cons_page {
 };
 
 
+/**
+ * The (global) pointer to the (global) freelist. Not sure whether this ultimately 
+ * belongs in this file.
+ */
+extern struct cons_pointer freelist;
+
+/**
+ * An array of pointers to cons pages.
+ */
+extern struct cons_page* conspages[NCONSPAGES];
+
+
+/**
+ * Frees the cell at the specified pointer. Dangerous, primitive, low
+ * level.
+ *
+ * @pointer the cell to free
+ */
+void free_cell(struct cons_pointer pointer);
+
+
+/**
+ * Allocates a cell with the specified tag. Dangerous, primitive, low
+ * level.
+ *
+ * @param tag the tag of the cell to allocate - must be a valid cons space tag.
+ * @return the cons pointer which refers to the cell allocated.
+ */
+struct cons_pointer allocatecell( char* tag);
+
+
 /**
  * initialise the cons page system; to be called exactly once during startup.
  */
 void conspagesinit();
 
+/**
+ * dump the allocated pages to this output stream.
+ */
+void dumppages( FILE* output);
+
 #endif