🧩 Singly Linked List in C — intlist

A C library for manipulating singly linked lists of integers, focused on simplicity, modularity, and functional-style operations (inspired by JavaScript and Python).

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🚀 Features

🔹 Basic operations

• Create from array (array_to_list)
• Insert (list_append, list_prepend, list_insert)
• Remove (list_pop, list_shift, list_remove_at)
• Length (list_length)

🔹 Access and search

• Access by index (list_at)
• Find index (list_index_of)
• Find by condition (list_find)
• Count occurrences (list_count)

🔹 Statistics

• Minimum (list_min)
• Maximum (list_max)
• Average (list_average)

🔹 Functional operations

• map → transform elements (list_map)
• filter → filter elements (list_filter)
• reduce → accumulate values (list_reduce)
• for_each → iterate with function (list_for_each)

🔹 Utilities

• Sort (list_sort)
• Reverse (list_reverse)
• Swap elements (list_swap)
• Concatenate lists (list_concat)
• Convert to string (list_join)

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📁 Project Structure

├── include/
│ └── intlist.h
├── src/
│ └── intlist.c
├── lib/
│ └── libintlist.a
└── main.c

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⚙️ Build Instructions

1️⃣ Compile source file

gcc -c src/intlist.c -Iinclude -o src/intlist.o

2️⃣ Create static library

ar rcs lib/libintlist.a src/intlist.o

3️⃣ Compile main program

gcc main.c -Iinclude -Llib -lintlist -o program

4️⃣ Run

./program

💡 Example Usage

#include <stdio.h>
#include "intlist.h"

int main()
{
    int arr[] = {1, 2, 3, 4};

    node *list = array_to_list(arr, 4);

    printf("Length: %zu\n", list_length(list));

    unload_list(list);
    return 0;
}

🧠 Concepts Covered

This project demonstrates:

• Data structures (linked lists)
• Dynamic memory management (malloc / free)
• Modular C design (.h + .c)
• Separate compilation (.o)
• Static libraries (.a)
• Function pointers (callbacks / higher-order functions)

⚠️ Memory Management

Every list must be freed with:

unload_list(list);

Strings returned by list_join must be freed:

free(string);

📌 Notes

• The library operates on integers (int) only
• Functions handle null pointers safely when applicable
• Allocation failures return NULL or false