55 lines
1.4 KiB
C
55 lines
1.4 KiB
C
/**
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* payloads/cons.h
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*
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* A cons cell.
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*
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* (c) 2026 Simon Brooke <simon@journeyman.cc>
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* Licensed under GPL version 2.0, or, at your option, any later version.
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*/
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#ifndef __psse_payloads_cons_h
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#define __psse_payloads_cons_h
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#include <stdbool.h>
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#include "memory/pointer.h"
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#include "memory/pso4.h"
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#define CONS_SIZE_CLASS 2
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/**
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* @brief A cons cell.
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*
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*/
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struct cons_payload {
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/** Contents of the Address Register, naturally. */
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struct pso_pointer car;
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/** Contents of the Decrement Register, naturally. */
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struct pso_pointer cdr;
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};
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struct pso_pointer car( struct pso_pointer frame_pointer );
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struct pso_pointer cdr( struct pso_pointer frame_pointer );
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struct pso_pointer cons( struct pso_pointer frame_pointer );
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struct pso_pointer destroy_cons( struct pso_pointer frame_pointer );
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struct pso_pointer make_cons( struct pso_pointer frame_pointer,
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struct pso_pointer car, struct pso_pointer cdr );
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/**
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* macro short-cuts for make_cons.
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*/
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// #define make_cons(frame_pointer,car,cdr) (cons(make_frame(2, frame_pointer, car, cdr)))
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/**
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* Variant which assumes a convention that the frame pointer will always be
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* called `frame_pointer`
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*/
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#define make_cons2(car,cdr) (cons(make_frame(2, frame_pointer, car, cdr)))
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#define c_car(p)(sequencep(p) ? pointer_to_object(p)->payload.cons.car : nil)
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#define c_cdr(p)(sequencep(p) ? pointer_to_object(p)->payload.cons.cdr : nil)
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#endif
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