#ifndef APFL_BYTECODE_H
#define APFL_BYTECODE_H

#ifdef __cplusplus
extern "C" {
#endif

#include "apfl.h"

#include "gc.h"

enum instruction {
    INSN_NIL,                 // ( -- nil)
    INSN_TRUE,                // ( -- true)
    INSN_FALSE,               // ( -- false)
    INSN_NUMBER,              // ( -- number), arg: number
    INSN_STRING,              // ( -- string), arg: string
    INSN_LIST,                // ( -- list), arg: count (preallocation hint)
    INSN_LIST_APPEND,         // ( list val -- list' )
    INSN_LIST_EXPAND_INTO,    // ( list list -- list' )
    INSN_DICT,                // ( -- dict )
    INSN_DICT_APPEND_KVPAIR,  // ( dict key value -- dict' )
    INSN_GET_MEMBER,          // ( list/dict key -- value )
    INSN_GET_BY_INDEX_KEEP,   // ( list/dict -- list/dict value ), arg: index
    INSN_VAR_GET,             // ( -- value ), arg: string
    INSN_VAR_SET,             // ( value -- value ), arg: string
    INSN_VAR_SET_LOCAL,       // ( value -- value ), arg: string
    INSN_VAR_NEW,             // ( -- ), arg: string
    INSN_VAR_NEW_LOCAL,       // ( -- ), arg: string
    INSN_MOVE_TO_LOCAL_VAR,   // ( value -- ), arg: string
    INSN_NEXT_LINE,           // ( -- )
    INSN_SET_LINE,            // ( -- ), arg: count (new line number)
    INSN_DROP,                // ( value -- )
    INSN_CALL,                // ( func list -- value )
    INSN_FUNC,                // ( -- func ), arg: body
};

union instruction_or_arg {
    enum instruction instruction;
    struct apfl_string *string;
    apfl_number number;
    size_t count;
    size_t index;
    struct instruction_list *body;
};

struct instruction_list {
    union instruction_or_arg *instructions;
    size_t len;
    size_t cap;

    int line;
};

const char *apfl_instruction_to_string(enum instruction);

struct instruction_list *apfl_instructions_new(struct gc *, int line);
void apfl_instructions_deinit(struct apfl_allocator, struct instruction_list *);

void apfl_gc_instructions_traverse(struct instruction_list *, gc_visitor, void *);

#ifdef __cplusplus
}
#endif

#endif