I think read will now read integers and symbols, but it's untested.

Everything compiles.

src/c/payloads/character.c

@@ -0,0 +1,34 @@
+/**
+ *  payloads/character.c
+ *
+ *  A character object.
+ *
+ *  (c) 2026 Simon Brooke <simon@journeyman.cc>
+ *  Licensed under GPL version 2.0, or, at your option, any later version.
+ */
+
+/*
+ * wide characters
+ */
+#include <wchar.h>
+#include <wctype.h>
+
+#include "memory/node.h"
+#include "memory/pointer.h"
+#include "memory/pso.h"
+#include "memory/pso2.h"
+#include "memory/tags.h"
+
+#include "ops/truth.h"
+
+#include "payloads/character.h"
+
+struct pso_pointer make_character( wint_t c) {
+	struct pso_pointer result = allocate( CHARACTERTAG, 2 );
+
+	if (!nilp(result)) {
+		pointer_to_object(result)->payload.character.character = (wchar_t) c;
+	}
+
+	return result;
+}

src/c/payloads/character.h

@@ -36,4 +36,5 @@ struct character_payload {
     wchar_t character;
 };
 
-#endif
+struct pso_pointer make_character( wint_t c);
+#endif

src/c/payloads/cons.c

@@ -13,6 +13,7 @@
 #include "memory/pointer.h"
 #include "memory/pso.h"
 #include "memory/pso2.h"
+#include "memory/pso4.h"
 #include "memory/tags.h" 
 
 #include "payloads/cons.h"
@@ -89,3 +90,19 @@ struct pso_pointer cdr( struct pso_pointer p ) {
 
     return result;
 }
+
+/**
+ * @brief When a cons cell is freed, its car and cdr pointers must be
+ * decremented.
+ *
+ * Lisp calling conventions; one expected arg, the pointer to the cell to
+ * be destroyed.
+ */
+struct pso_pointer destroy_cons( struct pso_pointer fp, struct pso_pointer env) {
+	if (stackp(fp)) {
+		struct pso4 *frame = pointer_to_pso4( fp);
+		struct pso_pointer p = frame->payload.stack_frame.arg[0];
+		dec_ref( car( p));
+		dec_ref( cdr( p));
+	}
+}

src/c/payloads/cons.h

@@ -32,6 +32,6 @@ struct pso_pointer cdr( struct pso_pointer cons );
 
 struct pso_pointer cons( struct pso_pointer car, struct pso_pointer cdr );
 
-bool consp( struct pso_pointer ptr );
+struct pso_pointer destroy_cons( struct pso_pointer fp, struct pso_pointer env);
 
 #endif

src/c/payloads/exception.c

@@ -11,10 +11,31 @@
 #include "memory/node.h"
 #include "memory/pointer.h"
 #include "memory/pso.h"
+#include "memory/pso4.h"
+#include "memory/tags.h"
 
 #include "payloads/exception.h"
 
-struct pso_pointer make_exception( struct pso_pointer message, struct pso_pointer frame_pointer, struct pso_pointer cause) {
+struct pso_pointer make_exception( struct pso_pointer message,
+		struct pso_pointer frame_pointer, struct pso_pointer cause) {
     // TODO: not yet implemented
     return nil;
-}
+}
+
+/**
+ * @brief When an exception is freed, all its pointers must be decremented.
+ *
+ * Lisp calling conventions; one expected arg, the pointer to the object to
+ * be destroyed.
+ */
+struct pso_pointer destroy_exception( struct pso_pointer fp,
+		struct pso_pointer env) {
+	if (stackp(fp)) {
+		struct pso4 *frame = pointer_to_pso4( fp);
+		struct pso_pointer p = frame->payload.stack_frame.arg[0];
+
+		// TODO: decrement every pointer indicated by an exception.
+	}
+
+	return nil;
+}

src/c/payloads/exception.h

@@ -27,4 +27,7 @@ struct exception_payload {
 struct pso_pointer make_exception( struct pso_pointer message,
 		struct pso_pointer frame_pointer, struct pso_pointer cause);
 
+struct pso_pointer destroy_exception( struct pso_pointer fp,
+		struct pso_pointer env);
+
 #endif

src/c/payloads/psse_string.c

@@ -18,8 +18,28 @@
 
 #include "memory/node.h"
 #include "memory/pointer.h"
+#include "memory/pso.h"
 #include "memory/pso2.h"
+#include "memory/pso4.h"
 #include "memory/tags.h"
 
 #include "ops/string_ops.h"
 #include "ops/truth.h"
+
+/**
+ * @brief When an string is freed, its cdr pointer must be decremented.
+ *
+ * Lisp calling conventions; one expected arg, the pointer to the object to
+ * be destroyed.
+ */
+struct pso_pointer destroy_string( struct pso_pointer fp,
+		struct pso_pointer env) {
+	if (stackp(fp)) {
+		struct pso4 *frame = pointer_to_pso4( fp);
+		struct pso_pointer p = frame->payload.stack_frame.arg[0];
+
+		dec_ref( cdr(p));
+	}
+
+	return nil;
+}

src/c/payloads/psse_string.h

@@ -35,4 +35,7 @@ struct string_payload {
 
 struct pso_pointer make_string( wint_t c, struct pso_pointer tail );
 
+struct pso_pointer destroy_string( struct pso_pointer fp,
+		struct pso_pointer env);
+
 #endif

src/c/payloads/read_stream.c

@@ -13,6 +13,9 @@
 
 #include "io/fopen.h"
 #include "memory/pointer.h"
+#include "memory/pso.h"
+#include "memory/pso2.h"
+#include "memory/tags.h"
 
 
 /**
@@ -23,7 +26,7 @@
  */
 struct pso_pointer make_read_stream( URL_FILE *input,
                                       struct pso_pointer metadata ) {
-    struct pso_pointer pointer = allocate( READTV, 2);
+    struct pso_pointer pointer = allocate( READTAG, 2);
     struct pso2 *cell = pointer_to_object( pointer );
 
     cell->payload.stream.stream = input;

src/c/payloads/read_stream.h

@@ -29,4 +29,7 @@ struct stream_payload {
     struct pso_pointer meta;
 };
 
+struct pso_pointer make_read_stream( URL_FILE *input,
+                                      struct pso_pointer metadata );
+
 #endif

src/c/payloads/stack.c

@@ -44,7 +44,7 @@ struct pso_pointer make_frame( struct pso_pointer previous, ...) {
 	for ( ; cursor < count && cursor < args_in_frame; cursor++) {
 		struct pso_pointer argument = va_arg( args, struct pso_pointer);
 
-		frame->payload.stack_frame.arg[cursor] = argument;
+		frame->payload.stack_frame.arg[cursor] = inc_ref( argument);
 	}
 	if ( cursor < count) {
 		struct pso_pointer more_args = nil;
@@ -64,3 +64,31 @@ struct pso_pointer make_frame( struct pso_pointer previous, ...) {
 
 	return frame_pointer;
 }
+
+/**
+ * @brief When a stack frame is freed, all its pointers must be decremented.
+ *
+ * Lisp calling conventions; one expected arg, the pointer to the object to
+ * be destroyed.
+ */
+struct pso_pointer destroy_stack_frame( struct pso_pointer fp,
+		struct pso_pointer env) {
+	if (stackp(fp)) {
+		struct pso4 *frame = pointer_to_pso4( fp);
+		struct pso4 * casualty =
+				pointer_to_pso4( frame->payload.stack_frame.arg[0]);
+
+		dec_ref( casualty->payload.stack_frame.previous);
+		dec_ref( casualty->payload.stack_frame.function);
+		dec_ref( casualty->payload.stack_frame.more);
+
+		for (int i = 0; i < args_in_frame; i++) {
+			dec_ref( casualty->payload.stack_frame.arg[0]);
+		}
+
+		casualty->payload.stack_frame.args = 0;
+		casualty->payload.stack_frame.depth = 0;
+	}
+
+	return nil;
+}

src/c/payloads/stack.h

@@ -39,4 +39,7 @@ struct stack_frame_payload {
 
 struct pso_pointer make_frame( struct pso_pointer previous, ...);
 
+struct pso_pointer destroy_stack_frame( struct pso_pointer fp,
+		struct pso_pointer env);
+
 #endif