Generics in Assembly Language

Assembly Language doesn’t have direct support for generics or high-level data structures like linked lists. However, we can demonstrate some of the concepts using macros and basic memory operations. This example will be significantly simplified and won’t directly correspond to the original Go code.

; Example of a "generic" macro for finding an element in an array
%macro FIND_INDEX 3
    mov eax, -1              ; Initialize return value to -1
    mov ecx, %2              ; Load array length
    mov esi, 0               ; Initialize index
.loop:
    cmp [%1 + esi * 4], %3   ; Compare current element with search value
    je .found
    inc esi
    loop .loop
    jmp .end
.found:
    mov eax, esi             ; Set return value to current index
.end:
%endmacro

section .data
    array dd 10, 20, 30, 40, 50
    array_len equ ($ - array) / 4
    search_val dd 30

section .text
global _start

_start:
    ; Use the FIND_INDEX macro
    FIND_INDEX array, array_len, dword [search_val]

    ; Convert result to string and print
    add eax, '0'              ; Convert to ASCII
    mov [result], al

    mov eax, 4                ; sys_write
    mov ebx, 1                ; stdout
    mov ecx, result           ; message to write
    mov edx, 1                ; message length
    int 0x80

    ; Exit program
    mov eax, 1                ; sys_exit
    xor ebx, ebx              ; exit code 0
    int 0x80

section .bss
    result resb 1

This Assembly code demonstrates a simplified version of the concept of generics using a macro. The FIND_INDEX macro acts as a “generic” function that can work with arrays of different types (although in this example, we’re only using 32-bit integers).

1. The FIND_INDEX macro takes three parameters: the array, its length, and the value to search for.

2. It iterates through the array, comparing each element with the search value.

3. If a match is found, it returns the index. Otherwise, it returns -1.

4. In the _start section, we use the macro to search for a value in an array.

5. The result is then converted to ASCII and printed to stdout.

This example doesn’t include a linked list implementation, as that would be quite complex in Assembly and wouldn’t directly relate to the generics concept. Instead, we focused on showing how a macro can be used to create a reusable piece of code that works with different data, which is one of the core ideas behind generics.

To assemble and run this program (assuming you’re using NASM and Linux):

$ nasm -f elf64 generics_example.asm
$ ld -o generics_example generics_example.o
$ ./generics_example
2

The output 2 indicates that the value 30 was found at index 2 in the array.

This Assembly example provides a basic illustration of the concept of generics, albeit in a much more low-level and limited way compared to high-level languages like Go or Java.