https://github.com/kaushalmodi/ptr_math

Pointer arithmetic in Nim
https://github.com/kaushalmodi/ptr_math

arithmetic c ffi nim pointer

Last synced: 4 months ago
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Pointer arithmetic in Nim

• Host: GitHub
• URL: https://github.com/kaushalmodi/ptr_math
• Owner: kaushalmodi
• License: mit
• Created: 2021-05-21T02:01:30.000Z (over 3 years ago)
• Default Branch: main
• Last Pushed: 2021-11-01T13:43:21.000Z (about 3 years ago)
• Last Synced: 2023-08-13T01:23:07.957Z (over 1 year ago)
• Topics: arithmetic, c, ffi, nim, pointer
• Language: Nim
• Homepage: https://kaushalmodi.github.io/ptr_math/
• Size: 234 KB
• Stars: 11
• Watchers: 3
• Forks: 1
• Open Issues: 1
• Metadata Files:
  • Readme: README.org
  • License: LICENSE

Awesome Lists containing this project

README

        
#+title: Pointer Arithmetic in Nim

#+author: Kaushal Modi

[[https://github.com/kaushalmodi/ptr_math/actions/workflows/test.yml][https://github.com/kaushalmodi/ptr_math/actions/workflows/test.yml/badge.svg]]

[[https://github.com/kaushalmodi/ptr_math/actions/workflows/docs.yml][https://github.com/kaushalmodi/ptr_math/actions/workflows/docs.yml/badge.svg]]

This module implements basic pointer arithmetic functionality.

* Documentation

[[https://kaushalmodi.github.io/ptr_math/][https://kaushalmodi.github.io/ptr_math/]]

* Installation

#+begin_example

nimble install ptr_math

#+end_example

* Quick Start

#+begin_src nim

import std/[strformat]

import ptr_math

var

  a: array[0 .. 3, int]

  p = addr(a[0])          # p is pointing to a[0]

for i, _ in a:

  a[i] += i

echo &"before                    : a = {a}"

p += 1                  # p is now pointing to a[1]

p[] = 100               # p[] is accessing the contents of a[1]

echo &"after p += 1; p[] = 100   : a = {a}"

p[0] = 200              # .. so does p[0]

echo &"after p[0] = 200          : a = {a}"

p[1] -= 2               # p[1] is accessing the contents of a[2]

echo &"after p[1] -= 2           : a = {a}"

p[2] += 50              # p[2] is accessing the contents of a[3]

echo &"after p[2] += 50          : a = {a}"

p += 2                  # p is now pointing to a[3]

p[-1] += 77             # p[-1] is accessing the contents of a[2]

echo &"after p += 2; p[-1] += 77 : a = {a}"

echo &"a[0] = p[-3] = {p[-3]}"

echo &"a[1] = p[-2] = {p[-2]}"

echo &"a[2] = p[-1] = {p[-1]}"

echo &"a[3] = p[0] = {p[0]}"

#+end_src

* Development

** Requirement

This library is tested using Nim /devel/ version. The version was

1.5.1 as of writing this on <2021-06-03 Thu>.

** Prep

Once you clone this repo, cd to the cloned directory and run the below

command *first* (before you execute any of the below "nim" commands):

#+begin_example

nim pullConfig

#+end_example

This will clone my global ~config.nims~ file into a

~/nim_config/~ directory. That will enable running the ~nim

test~ and ~nim docs~ commands.

** Testing

#+begin_example

nim test

#+end_example

** Generate doc

Create the HTML page and associated search index in ~/public/~.

#+begin_example

nim docs

#+end_example

* Credit

Most of the code in this library is from [[https://forum.nim-lang.org/t/1188#7366][this code snippet]] authored by

Nim Forum user /Jehan/.