A second attempt to learn Swift

Posted on 2020-06-21 14:48 +0100 in Coding • Tagged with Swift, Apple, coding • 4 min read

It's five years ago this month that I bought myself my first macOS (then OS X) device. After many years of having a Windows machine as my daily driver, which was also my work machine (I worked from home), I decided it was high time that I returned to having a Unix-a-like system on my desk too. For a decade or so, starting in the later-90s, I'd had a GNU/Linux desktop. I still had a Windows desktop (until a couple of years ago most of my work was on DOS and Windows), but thanks to the wonders of a KVM, and later an X server that ran on Windows, my personal hacking was done on a GNU/Linux desktop.

But as things moved around, priorities changed, as life moved on, the GNU/Linux boxes got retired and never quite replaced. Eventually, in 2015, I found myself with the means and desire to recover that sort of setup. Long story short, after a lot of reading up and weighing up options I decided that the best option for a desktop Unix was... an iMac!

I loved it. Sure, there were lots of little things on the surface that were different or annoying or just plain not as cool as the Mac fans would tell you, but under the hood I found what I needed: a Unix CLI with all the things I knew well. And, of course, it ran GNU Emacs just fine; that was the really important thing for me.

Pretty much right away I decided that it might be fun to learn the tools necessary to develop native Mac apps, and perhaps even iOS apps. I downloaded XCode, bought a book, and started working through it. Having got that book, I decided it might be interesting to own an iOS device too. So, sort of needing an MP3 player, and having no wish to get an iPhone, I got myself an iPod Touch. So I was all set to devour the Swift book, write some stuff for OS X, create an iOS app or two, and... life happened. Stuff cropped up that distracted me from taking that further and I never really returned to working through the book.

Fast forward to now and that initial iMac and iPod purchase spiralled a wee bit. Next after the iPod was an iPad Mini, when my Nexus 7 was starting to show its age and it was obvious that Google wasn't going to produce any more good Android tablets. Then, when I needed a very portable Unix-a-like machine for trips between where I was living and Edinburgh, I got myself a MacBook Air. Since then the iPod Touch has been replaced once, as has the iPad Mini. I now also own an iPad and a MacBook Pro. Unless Apple screw up and turn Macs into something unusable for developers (there are rumours), I imagine I'll be using Apple devices for some time to come now.

And then, last month, having finally got frustrated with where Google were going with Android and the Pixel series, I jumped ship to the iPhone 11.

As of right now I'm in a situation where I'm all about the Apple ecosystem regarding hardware and operating systems (including for my work machine), all of which is there to support my heavy use of the Google ecosystem (actually, the one bit of Google hardware I still lean on heavily is the Google Home -- I have 3 around my home).

So... given all of that, I thought it was time to look at returning to learning Swift, with a view to writing some native macOS and i(Pad)OS stuff. I soon realised that the book I'd bought back in 2015 was rather out of date. It covers Swift 1.2 -- we're now up to 5.2! Given this, and given I've forgotten pretty much everything I'd read at the time, I decided I should start again from scratch.

This weekend I've started reading my way though iOS Programming Fundamentals with Swift. While this obviously has an emphasis on iOS, I'm already finding that the first part of the book is a really great introduction to the Swift language in general. The pace seems just right, and the way topics are grouped makes it easy enough for me to skip over what's obvious (I don't need to know what objected-oriented programming is, and what the difference between a class and an object is, etc) and read up on the detail of this particular language when it comes to general concepts I know (knowing the differences between a class, struct and enum in the language is important, for example).

I've yet to write a line of code, but I'm fine with that. The book is spending a lot of time introducing the language before encouraging you to fire up XCode, and I'm okay with that. I'm never a fan of being asked to write out code that I can't properly follow -- that just makes stuff look like magic when it's far more educational to know what's going on. What I am finding is I'm making lots of notes that are either "oh, yeah, this is cool, I like this idea!" or "WTF are you kidding me?!?". Which is really nice -- it's always great to learn a new language that's a bit different from what you normally use.

My plan then, over the next few weeks, it to keep at this and hopefully document my journey. I think I'd like to write a short series of TIL-type posts; nothing too long, just some new thing I read or discovered and my reaction to it. So, if you happen to follow this blog, I apologise in advance for any Swift-spam.

You have been warned. ;-)

Getting started

Posted on 2019-11-17 11:36 +0000 in Coding • Tagged with Coding, learning • 2 min read

By coincidence, in a couple of different places over the last couple of weeks, the subject of "how do I progress in leaning to program?" has cropped up. For me, I think the approaches and solutions tend to be the same for when I want to get my head around a new language: read good examples of idiomatic code, read other related materials, find a problem you care about and implement a solution (ideally something you'll directly benefit from, or at least others may benefit from). Hence the 5x5 puzzle and Norton Guide reader projects I mentioned in my previous post.

Of course, not everyone has problems that they need solving in a way that would work for this approach. So another approach I've recommended in the past is to go looking on somewhere like GitHub and find projects that promote "low-hanging fruit" issues in a way that's designed to be friendly for those who are new to development, new to contributing or new to the problem domain.

While looking for examples of this yesterday I stumbled on Awesome for Beginners. This looks like a great list and one I'm going to keep bookmarked for future reference. Now, this particular list does seem to have an emphasis on pulling in people who are new to contributing to a project rather than new to development, but it does strike me as a good place to start looking no matter where you're coming from.

I know I'm going to start having a wander around that list. It's always nice to contribute and I feel there's real personal benefit in actively solving a problem that someone else has and welcomes help with.

On to something new

Posted on 2017-12-12 13:59 +0000 in Life • Tagged with coding, work, life, news • 2 min read

Today is a fairly significant day for me. For the past 21 (and a bit) years I've worked for the same company. I know that, for lots of people in my industry, that's a hell of a long time to be in one position. It was a setup that served me pretty well; the company was small (I'm not much of a big company person), I generally got to dictate the development tools and direction, and I also got to work from home.

The working from home part was especially helpful as other life events involved me and happened around me. The job I've been in has seen a marriage come and go, and a move from Hampshire to Lincolnshire, and then from Lincolnshire to Midlothian. There's been a few adventures along the way.

But, three months ago, I got a call to say that I was to be made redundant. This sucked, obviously. It also appeared pretty stupid on the part of my employer: a company that is based around software had decided it no longer wanted an in-house software developer. A bold, and I think unwise, choice. From this point on they've decided to only go with contract developers and only contract developers from overseas (or so the story goes).

As it goes, things have turned out okay. Today is my last day with my old employer and, as I'm sat here typing this out while having some lunch, I'm actually glad that it's coming to a close and that I can get to move on.

I have a new employer, and will be starting in my new position during the first week of January. It'll be very different. It'll all be different. Not only will I be back working in an office (one where jeans and t-shirts are the norm, thankfully!), I'm also going to be working in an industry (as a developer still, of course) that I have no background in and no real knowledge of. It's going to be a seriously exciting challenge.

New book

Over the next couple of weeks I've got a fair amount of background reading (and video watching) to be doing. This isn't so much that I can get on with the job of development (although there will be a good bit of that to do too -- who doesn't want to be trying to understand new options for development?), it's more about understanding the language of the industry I'll be in and so that I can understand the needs of my users.

Goodbye fashion retail and all related things. Hello genetics and... well, I don't know, I'm going to find out. :)

More revamping of my Emacs config

Posted on 2017-07-13 15:25 +0100 in Emacs • Tagged with Emacs, Lisp, coding, Emacs Lisp • 2 min read

I've been pretty quiet on here since I last wrote about how I'd done a further revamp of my Emacs config, so I thought that subject would be a good reason to write another blog post.

It'll be a mostly short one, and one to muse over something that's been bugging me for a while now: my decision to lean heavily on customize to set all sorts of settings.

Initially, when I nuked my original config over a year ago, it seemed to make a lot of sense. Let all the tweaks and set values "hide" in a file of their own and try and keep the hand-edited config files as small and as clean as possible. Recently though I've got to thinking that this obscures too much, hides too much detail, and removes the ability to actually document what I'm doing and why. It also does make it tricky to adapt some settings to different platforms or even environments on a single platform.

Another problem I've run into is this: when I made the second round of changes and decided to lean heavily on use-package, I soon ran into the minor issue of some packages not making sense, or even being needed, on some platforms (stuff that's useful on my macOS machines isn't always useful on my Windows machines, that sort of thing). While use-package can handle this easily thanks to the :if keyword, I'm still left with the fact that package-selected-packages still gets populated.

Having package-selected-packages contain a list of installed packages likely makes sense if you're using just the Emacs package system and you're not doing the installing with use-package and :ensure. But with use-package and :ensure I feel like I've got far more control over things and can adapt what gets installed when depending on which Emacs I'm running where.

But, because I'm syncing my ~/.emacs.d/.custom.el to all my machines too, any use-package that has a :if to not bother using a package has little effect because the package still ends up being listed/loaded/seen as part of the installation.

Ideally, I think, I'd like to be able to have package-selected-packages held in its own file, or I'd only ever use ~/.emacs.d/.custom.el for local stuff (and so stop syncing it).

Starting today I'm going about a process of moving as much as I can out of ~/.emacs.d/.custom.el and into hand-edited files. In some respects I guess I am going back to how I used to manage Emacs configuration, but this time it's not a massive monolithic file-of-Lisp, it's neatly broken down into sensible sections and it's also biased towards a "grab and config this package" approach.

Meanwhile, I've not seen any good discussions online about customize vs "hand-edit", which strikes me as a little odd as it feels like the perfect "religious issue" for people to have endless disagreements over. I guess, over the next couple or so weeks, I'll find out if switching back was a good idea.

Another revamp of my emacs config

Posted on 2017-04-01 10:02 +0100 in Emacs • Tagged with Emacs, Lisp, Emacs Lisp, coding • 4 min read

Just under a year ago I decided to totally rewrite my GNU emacs config. As I wrote at the time, it'd been following me around all sorts of machines since the early 1990s, starting life on an OS/2 Warp machine and travelling via MS-DOS, GNU/Linux, Windows and, these days, macOS.

The changes I made last year have served me really well, but there were two related issues with it that bothered me a little: the fact that I was maintaining a local library of elisp code in the repository and, worse still, I was storing the packages I'd installed from elpa and melpa in the repository as well.

While this did mean it was pretty easy for me to start up a new installation of emacs on a machine -- all I had to do was clone the repo and run up emacs -- I wasn't happy with the duplication involved. I didn't like holding code in my .emacs.d repo that was already held in package archives.

The solution I saw was in two parts:

  1. Get some of my code, that might be useful to others, into melpa.
  2. Somehow sort my own package archive for my personal code.

Over the past week or so I've worked on this approach. It initially started with me tackling item 1 above: I tidied up and submitted obfusurl.el, protocols.el, services.el, thinks.el and uptimes.el. This was a really helpful process in that it allowed me to brush up on my elisp and emacs knowledge. It's a good 15+ years since I last wrote any significant elisp code and things have moved on a little in that time.

Having done that I'd managed to move a handful of my own packages out of my local library of code, and so out of my .emacs.d repo, but it left me with the problem of what to do with the rest of it.

That's when I discovered package-x and:

,----[ C-h f package-upload-buffer RET ]
| package-upload-buffer is an interactive compiled Lisp function in
| package-x.el.
| (package-upload-buffer)
| Upload the current buffer as a single-file Emacs Lisp package.
| If package-archive-upload-base does not specify a valid upload
| destination, prompt for one.

(plus package-upload-file too, of course). This meant I could, in effect, start my own personal package archive and look at tackling issue 2 above.

This did give me one small problem though: how and where would I host the archive? I did consider hosting it on a DigitalOcean droplet, but that felt a little like overkill for something so simple. And then I realised: GitHub Pages! All I needed to do was keep the package archive in its own repo (which I would have done anyway) and then make the whole repo the source for a GitHub Pages site. A quick test later and... it worked!

So, by this point, I'd farmed some of my code off to melpa, and now had the rest of it in "delpa" (which I'd called my personal archive). I could now use the emacs package management system to install third party packages and also my own.

But I was still left with one issue: I was still holding the installed packages inside my .emacs.d repo by way of ensuring that all machines were in sync in terms of what was installed. Now I needed to work out how to solve that.

Around this time, as luck would have it, @tarsius had suggested I look at a package called use-package by @jwiegley. This was the bit I was missing.

With use-package I would be able to declare which packages I needed, how they'd be installed and, most important of all, it could be set to handle the fact that the package wasn't even installed. If a package is requested and there is no local install use-package is smart enough to get the emacs package system to install it.

So, given that, all I need to do was create a startup file that would declare the packages I use and I'd have a setup that should, once I'd cloned .emacs.d, self-install.

Except... yeah, one more issue. use-package isn't part of GNU emacs yet so I'd need a method of getting it to auto-install so it could then handle everything else. As it was that was as easy as adding this to the start of my init.el.

;; Make sure the package system is up and running early on.
(require 'package)
(add-to-list 'package-archives '("melpa" . "http://melpa.org/packages/"))
(add-to-list 'package-archives '("delpa" . "http://blog.davep.org/delpa/"))

;; Bootstrap `use-package'
(unless (package-installed-p 'use-package)
  (package-install 'use-package))

With that in place I was able to nuke all my config on a machine, clone a fresh copy of .emacs.d (having now ceased tracking and storing the installed packages in that repo), run up emacs, wait a few moments and then find that everything was installed and ready to use.


My .emacs.d is now a lot smaller than it was before and, I think, even easier to maintain. Right now I think I'm very close to the ideal emacs config that I wanted to create when I did the complete rewrite a year ago.


Posted on 2017-03-10 10:14 +0000 in Coding • Tagged with Norton Guide, Coding, JavaScript • 3 min read

Like many programmers, I have a couple of "Hello, World" projects that I've carried with me over the years. One is 5x5 (which has been used to get to grips with things as diverse as the Palm Pilot and GNU emacs). Another is Norton Guides database readers.

I've made Norton Guides tools that have allowed web servers to serve guides (w3ng), that have allowed you to convert guides to HTML (ng2html), that have let you read guides on OS/2 and GNU/Linux (eg) and also have let you read guides in Microsoft Windows (weg). It's a problem I know fairly well and one where I know the solution well enough so I can concentrate on learning the new language or environment.

Recently I wanted to get to grips with some "pure" ES6 coding while also getting to know node.js. A new version of the Norton Guide code, written for this environment, seemed like a good thing to do.

And so jsNG was born.

At its core is a library of code for opening and reading data from Norton Guides databases. While I doubt it's good ES6 code, or even good node.js code, it's been very useful in giving me a fun problem to solve and it'll carry on being something I'll tweak and tinker with by way of trying new things out.

On top of this I've built a handful of tools for working with Norton Guides databases. The most useful one at the moment (the others are more in the "test the library" than the "make something handy with the library" category) is ngserve. This is designed as a simple Norton Guides database HTTP server.

ngserve in action

When run, you give it a list of guides to serve:

Starting ngserve

and it does the right thing. It has a small number of command line options that help configure what it does:

ngserve command line options

Possibly the most useful are the ones that let you change how it handles "higher" DOS characters and, if you don't like the default colours and stuff, the option that lets you point to your own style sheet (note for now you'll need to host the stylesheet somewhere else -- ngserve won't serve it for you; I'm aiming to change that in some way in the near future).

jsNG does have a fairly basic design compromise at its heart. In the very early version I started out using the async functions for opening and reading the guides. This got very tedious very quickly and I could see that it was going to make for a very messy library with a very messy interface. While it might not be in the spirit of node.js programming I decided to go with the sync version of the file IO functions and code up the core library based around this.

This approach also means that I took another leap that I never have done with Norton Guides before: rather than doing the traditional thing of keeping an open handle into them and reading direct from the file as you navigate the guide, I simply read it all into a buffer in one go and keep it in memory. This is a "guides are small, memory is cheap, things will go faster" approach.

It does mean that when you load up a load of guides into ngserve they're all sat in memory. The upside of this is that things should be a lot faster and the code is a lot easier to follow (I think). To put this in some perspective: I have a directory here that contains 110 Norton Guides files. They total 36M in size. If that seems like a lot of stuff to hold in memory... remind me how much is being used by your web browser so you can look at some hilarious kittens. ;)

Anyway, that's where I'm at with it right now. The code is mostly settled and mostly tidy. I need to write up some documentation for it (and so I need to take a look at good JavaScript documentation tools) and perhaps tinker with ngserve a little more. I'd also like to do a new version of ng2html with this -- a version that makes it far easier to control the style of the output. I'm also tempted to do a CLI-based reader in pure ES6; something similar to EG or WEG.

All in good time.

Evernote's confusing menu

Posted on 2016-10-31 11:38 +0000 in Tech • Tagged with Evernote, coding • 2 min read

The other day I stumbled on a tip about Evernote. It was a snippet of information in a bigger post on the Evernote blog so I saved it to Evernote (obviously) to take a look at later.

The tip was that Ctrl-Cmd-B in Evernote (on the Mac) will format a body of text as source code. While I'm not in the habit of using Evernote to store code, not even snippets of code (that's something far better served by Gist), it seemed like something worth committing to memory.

This morning, while finally in front of a suitable machine, I took a look. Sure enough, there's the menu option.

Code formatting menu option

Handy! So I created a test note with some code in it so that I could see how it formatted it. I was curious to see if it just did simple fixed text or if it offered options to highlight various languages (I didn't hold out much hope for the latter, but it was worth a look).

That's when it got odd.

After I created a note and went to format some code, the menu option disappeared!

Lack of code formatting menu option

From what I can tell, once it's gone, there's no way to get it back. At least, not until you actually close down Evernote and start it up again.

Frustratingly, none of this is the case in the Windows version. While the key combination is different there, the menu option is available and stays available.

The version of Evernote I have (on my iMac and my Macbook) is 6.9.2. The version number on Windows is 6.4.2 (after checking for updates -- I'm going to guess that the Mac and Windows version numbers don't match on purpose).

Goodness knows what's going on here. All I can imagine is that it has something to do with a thread I found on Evernote's support forum that suggests that code block formatting is some sort of test/beta feature and can only be enabled via a settings option that isn't available via the version downloaded from the Apple App Store.

So, at some point, I guess I'm going to have to uninstall Evernote from the Macbook and the iMac, reinstall from the Evernote website itself, and try this again. All of which seems a bit silly when the menu option is there and visible when I run Evernote up!

Edit to add: Sure enough, removing the App Store version and installing the version from Evernote's own website, and then going into preferences and enabling the option, sorted it. It's still really odd they'd promote the facility via the blog and not mention it, and also very odd that the option would always show until the first time you're in a position to use it, and then it'd disappear.