/**
 *  ops/mapcar.c
 *
 *  Post Scarcity Software Environment: mapcar.
 *
 *  map a function across a sequence of forms.
 *
 *  (c) 2026 Simon Brooke <simon@journeyman.cc>
 *  Licensed under GPL version 2.0, or, at your option, any later version.
 */

#include "debug.h"

#include "memory/node.h"
#include "memory/pointer.h"
#include "memory/pso.h"
#include "memory/pso4.h"
#include "memory/tags.h"

#include "ops/eval_apply.h"
#include "ops/reverse.h"
#include "payloads/stack.h"
#include "ops/truth.h"

#include "payloads/cons.h"

struct pso_pointer lisp_mapcar( struct pso_pointer frame_pointer ) {
	struct pso_pointer result = nil;
	struct pso4* frame = pointer_to_pso4(frame_pointer);
    debug_print( U"Mapcar: ", DEBUG_EVAL, 0 );
    debug_dump_object( frame_pointer, DEBUG_EVAL, 0 );
    int i = 0;

    for ( struct pso_pointer c = frame->payload.stack_frame.arg[1]; c_truep( c );
          c = c_cdr( c ) ) {
        struct pso_pointer expr =
            push_local( frame_pointer,
                make_cons( frame_pointer, frame->payload.stack_frame.arg[0],
                    make_cons( frame_pointer, c_car( c ), nil ) ) );

        debug_printf( DEBUG_EVAL, 0, U"Mapcar %d, evaluating ", i );
        debug_print_object( expr, DEBUG_EVAL, 0 );
        debug_println( DEBUG_EVAL);

        struct pso_pointer r = lisp_eval( push_local( frame_pointer, make_frame(1, frame_pointer, expr)));

        if ( exceptionp( r ) ) {
            result = r;
            break;
        } else {
            result = push_local( frame_pointer, make_cons( frame_pointer, r, result ));
        }
        debug_printf( DEBUG_EVAL, 0, U"Mapcar %d, result is ", i++ );
        debug_print_object( result, DEBUG_EVAL, 0 );
        debug_println( DEBUG_EVAL);
    }

    result = consp( result ) ? c_reverse( frame_pointer, result ) : result;

    debug_print( U"Mapcar returning: ", DEBUG_EVAL, 0 );
    debug_print_object( result, DEBUG_EVAL, 0 );
    debug_println( DEBUG_EVAL );

    return result;
}