Thomas Zastrow, MPCDF Seminar 01-08-20

import nimx/window

import nimx/text_field

import nimx/button

proc startApp() =

var wnd = newWindow(newRect(40, 40, 800, 600))

let label = newLabel(newRect(20, 20, 300, 20))

label.text = "I'm a label with some umlauts: öüäß"

wnd.addSubview(label)

let tf = newTextField(newRect(20, 80, 180,30))

wnd.addSubview(tf)

let b = newButton(newRect(20,50,180,30))

b.title="Click me"

b.onAction do():

tf.text = "Awesome!!!"

wnd.addSubview(b)

let cb = newCheckbox(newRect(20, 110, 50, 16))

cb.title = "It is a checkbox"

wnd.addSubview(cb)

let rb = newRadiobox(newRect(20, 140, 50, 16))

rb.title = "And a radio button"

wnd.addSubview(rb)

runApplication:

startApp()

The NIMProgrammingLanguage

Thomas Zastrow, MPCDF Seminar 01-08-20

https://www.heise.de/developer/mel-

dung/Programmiersprachen-Nim-

liegt-als-stabile-Version-1-0-vor-4537

790.html

Thomas Zastrow, MPCDF Seminar 01-08-20

What is Nim?

„Nim is a statically typed compiled systems programminglanguage. It combines successful concepts from maturelanguages like Python, Ada and Modula“

nim-lang.org

„Today, Nim compiles to C, C++, JavaScript, and Objective-C. Thegoal for Nim is to be as fast as C, as expressive as Python, andas extensible as Lisp.“

https://en.wikipedia.org/wiki/Nim_(programming_language)

Thomas Zastrow, MPCDF Seminar 01-08-20

How it works

Nim Code Nim Compiler

C Compiler

C++ Compiler

Objective C

Compiler

JavaScript

Executable

Thomas Zastrow, MPCDF Seminar 01-08-20

First example

var x : intvar s = „Hello World!“

x = 2if x mod 2 == 0: echo "x is even!"else: echo "x is odd!"

nim compile demo01.nim

Creates executable demo01

C code is stored in ~/.cache/nim

Statically typed

Python like

syntax

Thomas Zastrow, MPCDF Seminar 01-08-20

Common Constructs

var ar : array[6, int]

for i in countup(0,5):

ar[i] = i

var se1 : seq[string] = @["a", "b", "c"]

type

Person = object

name : string

age : intproc add * (a,b:int) : int =

return a + b

import tables

import strtabs

var t = initTable[string, int]()

t["c"] = 10

t["b"] = 20

t["a"] = 30

import json

var jsonNode = parseJson("""{"value": 3,

"somestuff" : {"sport" : ["Soccer",

"Billard", "Running"], "nothing" : null}}""")

echo jsonNode["value"]

Thomas Zastrow, MPCDF Seminar 01-08-20

Further Stuff

• Macros: functions which are transforming aNim syntax tree into something else atcompile time

• Optional: Object Oriented Programming• Generics• Templates• ...

Thomas Zastrow, MPCDF Seminar 01-08-20

The Nimble Package Directory

• Central place for Nim packages• Access via „nimble“ command

https://nimble.directory/

nimble list

nimble search <keyword>

nimble install <package>

...

Thomas Zastrow, MPCDF Seminar 01-08-20

Some Packages

Jester: Web serverimport htmlgen

import jester

routes:

get "/":

resp h1("Hello world")

Nimx: GraphicalUser Interfaces

db: Unified db accessmoduleSupports MySQL,

Postgres and SQlite

... and many more!

Thomas Zastrow, MPCDF Seminar 01-08-20

IDE: Nim Plugin for MS Visual Code

Thomas Zastrow, MPCDF Seminar 01-08-20

Nim on a Raspberry Pi

• In Raspian, only an old Nim version (0.19.4-1)is available via the package management

• Let’s compile Nim itself:wget https://nim-lang.org/download/nim-1.0.4.tar.xz

unxz nim-1.0.4.tar.xz

cd nim-1.0.4/

sh build.sh

bin/nim c koch

./koch tools

export PATH="/home/pi/nimsource/nim-1.0.4/bin:$PATH"

export PATH="/home/pi/.nimble/bin:$PATH"

„The koch program is Nim's maintenance script. It is a replacement for

make and shell scripting with the advantage that it is much more

portable.“ (https://nim-lang.org/docs/koch.html)

Thomas Zastrow, MPCDF Seminar 01-08-20

Nim on a Raspberry Pi

Compiling Nim apps on a Raspberry Pi 4:

nim compile demo1.nim

file demo1demo1: ELF 32-bit LSB executable, ARM, EABI5

version 1 (SYSV), dynamically linked, interpreter

/lib/ld-linux-armhf.so.3, for GNU/Linux 3.2.0, ...

(Executable runs also on Raspberry Pi Zero)

Thomas Zastrow, MPCDF Seminar 01-08-20

Conclusion

Nim feels like ... ... but runs like

*very comfortable* *very fast*

Thomas Zastrow, MPCDF Seminar 01-08-20

Conclusion

• If you are an experiencedC developer: No.

• In any other cases: Yes.

To Nim or not to Nim?

https://nim-lang.org/

Thomas Zastrow, MPCDF Seminar 01-08-20

import nimx/window

import nimx/text_field

import nimx/button

proc startApp() =

var wnd = newWindow(newRect(40, 40, 800, 600))

let label = newLabel(newRect(20, 20, 300, 20))

label.text = "I'm a label with some umlauts: öüäß"

wnd.addSubview(label)

let tf = newTextField(newRect(20, 80, 180,30))

wnd.addSubview(tf)

let b = newButton(newRect(20,50,180,30))

b.title="Click me"

b.onAction do():

tf.text = "Awesome!!!"

wnd.addSubview(b)

let cb = newCheckbox(newRect(20, 110, 50, 16))

cb.title = "It is a checkbox"

wnd.addSubview(cb)

let rb = newRadiobox(newRect(20, 140, 50, 16))

rb.title = "And a radio button"

wnd.addSubview(rb)

runApplication:

startApp()

Thank you ;-)