peony / src / stackarray.hpp

// (c) 2020 Vlad-Stefan Harbuz <[e-mail]>

#pragma once

#include "memory.hpp"

template <typename T, u32 capacity>
class StackArray {
public:
    T items[capacity] = {{}};
    u32 length = 0;
    bool is_sparse = false;
    u32 starting_idx = 0;

    T* push() {
        assert(this->length < capacity);
        u32 new_idx = this->length;
        this->length++;
        T* new_slot = &this->items[new_idx];
        return new_slot;
    }

    T* push(T new_item) {
        T* new_slot = push();
        *new_slot = new_item;
        return new_slot;
    }

    T* get(u32 idx) {
        assert(idx >= this->starting_idx && idx < capacity);
        if (idx >= this->length) {
            assert(this->is_sparse);
            this->length = idx + 1;
        }
        return &this->items[idx];
    }

    T* operator[](u32 idx) {
        return get(idx);
    }

    template <typename F>
        T* find(F match) {
            for (auto item = begin(); item < end(); item++) {
                if (match(item)) {
                    return item;
                }
            }
            return nullptr;
        }

    T* begin() {
        return &this->items[this->starting_idx];
    }

    T* end() {
        return &this->items[this->length];
    }

    void clear() {
        memset(this->items, 0, sizeof(this->items));
        this->length = 0;
    }

    void delete_elements_after_index(u32 idx) {
        memset(&this->items[idx], 0, sizeof(T) * (this->length - idx));
        this->length = idx;
    }
};