mchakravarty

// Put this into an Xcode 12.0 multiplatform app

import SwiftUI

struct ContentView: View {
    @State var text = "Hello!"

    var body: some View {
        VStack {
            TextEditor(text: $text)

mchakravarty

infix operator ?! { }

func ?!<A>(v: A?, msg: String) -> A {
  if let v = v {
    return v
  } else {
    println(msg)
    exit(1)
  }
}

mchakravarty

Keybase proof

I hereby claim:

• I am mchakravarty on github.
• I am tacticalgrace (https://keybase.io/tacticalgrace) on keybase.
• I have a public key whose fingerprint is 234C FFAE 8B87 C024 2C6B 8DD4 888F 3E64 4E8B F866

To claim this, I am signing this object:

mchakravarty

Installation instructions

Prerequisites: OS X with the latest Xcode and command line tools installed (or just the command line tools)

(If you haven't got a machine with OS X, please pair up with a participant who has got a Mac at the workshop.)

Install the Haskell Platform (2013.2.0.0, 64 bit): http://www.haskell.org/platform/mac.html (Note the special installation instructions for using the Haskell Platform with Xcode 5.)

Now, that you have got a Haskell system, install language-c-inline, the library implementing inline C code for Haskell.

mchakravarty

"/usr/bin/ghc" -M -static  -H32m -O -Werror -Wall -H64m -O0  -package-db libraries/bootstrapping.conf  -package-name Cabal-1.18.0 -hide-all-packages -i -ilibraries/Cabal/Cabal/. -ilibraries/Cabal/Cabal/dist-boot/build -ilibraries/Cabal/Cabal/dist-boot/build/autogen -Ilibraries/Cabal/Cabal/dist-boot/build -Ilibraries/Cabal/Cabal/dist-boot/build/autogen -Ilibraries/Cabal/Cabal/.    -optP-include -optPlibraries/Cabal/Cabal/dist-boot/build/autogen/cabal_macros.h -package array-0.4.0.1 -package base-4.6.0.1 -package bytestring-0.10.0.2 -package containers-0.5.0.0 -package deepseq-1.3.0.1 -package directory-1.2.0.1 -package filepath-1.3.0.1 -package pretty-1.1.1.0 -package process-1.1.0.2 -package time-1.4.0.1 -package unix-2.6.0.1 -Wall -fno-ignore-asserts -fwarn-tabs -XHaskell98 -XCPP -fno-warn-deprecated-flags  -no-user-package-db -rtsopts -w     -odir libraries/Cabal/Cabal/dist-boot/build -hidir libraries/Cabal/Cabal/dist-boot/build -stubdir libraries/Cabal/Cabal/dist-boot/build -dep-makefile libraries/Cabal/Ca

mchakravarty

data PreExp exp = Val Int
                | Add exp exp

newtype Exp = Exp (PreExp Exp)  -- this is just a normal expression

data AttrExp = AttrExp Attr (PreExp AttrExp)   -- an attributed expression

data Attr = ...

mchakravarty

{-# LANGUAGE GADTs, DataKinds, KindSignatures, StandaloneDeriving #-}

module BezierVec (bezier) where
  
infixr :::

-- encoding of natural numbers (zero and successor of a natural)
data Nat = Z | S Nat

-- indexed vectors are lists whose first type argument encodes the length of the list

mchakravarty

{-# LANGUAGE TemplateHaskell, QuasiQuotes #-}

module TestInlineObjC (objc_initialise, dumpURL) where

import Language.C.Quote.ObjC
import InlineObjC

objc_import ["<Foundation/Foundation.h>"]

mchakravarty

dumpURL :: String -> IO ()
dumpURL urlString
  = do
    { urlData <- $objc 'urlString [cstm| {
                   return [NSString stringWithContentsOfURL: [NSURL urlWithString: urlString] 
                                    encoding: NSUTF8StringEncoding 
                                    error: NULL];
                 } |]
    ; putStr urlData
    }

mchakravarty

Welcome to Drift!

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