/**
 * lispops.h
 *
 * List processing operations.
 *
 * The general idea here is that a list processing operation is a
 * function which takes two arguments, both cons_pointers:
 *
 * 1. args, the argument list to this function;
 * 2. env, the environment in which this function should be evaluated;
 *
 * and returns a cons_pointer, the result.
 *
 * They must all have the same signature so that I can call them as
 * function pointers.
 *
 *
 * (c) 2017 Simon Brooke <simon@journeyman.cc>
 * Licensed under GPL version 2.0, or, at your option, any later version.
 */

/*
 * special forms 
 */
struct cons_pointer lisp_eval( struct stack_frame *frame,
                               struct cons_pointer env );
struct cons_pointer lisp_apply( struct stack_frame *frame,
                                struct cons_pointer env );
struct cons_pointer lisp_quote( struct stack_frame *frame,
                                struct cons_pointer env );

/*
 * functions 
 */
struct cons_pointer lisp_cons( struct stack_frame *frame,
                               struct cons_pointer env );
struct cons_pointer lisp_car( struct stack_frame *frame,
                              struct cons_pointer env );
struct cons_pointer lisp_cdr( struct stack_frame *frame,
                              struct cons_pointer env );
struct cons_pointer lisp_assoc( struct stack_frame *frame,
                                struct cons_pointer env );
struct cons_pointer lisp_eq( struct stack_frame *frame,
                             struct cons_pointer env );
struct cons_pointer lisp_equal( struct stack_frame *frame,
                                struct cons_pointer env );
struct cons_pointer lisp_read( struct stack_frame *frame,
                               struct cons_pointer env );
struct cons_pointer lisp_print( struct stack_frame *frame,
                                struct cons_pointer env );
/**
 * Get the Lisp type of the single argument.
 * @param frame My stack frame.
 * @param env My environment (ignored).
 * @return As a Lisp string, the tag of the object which is the argument.
 */
struct cons_pointer
lisp_type( struct stack_frame *frame, struct cons_pointer env );

/*
 * neither, at this stage, really 
 */
struct cons_pointer lisp_throw( struct cons_pointer message,
                                struct stack_frame *frame );