For those that haven’t see it before on my blog, Amberfell is a resource collecting video game set in a steampunk alternate history. It has some vague similarities with Minecraft but may play a bit more like Warcraft. It’ll support singleplayer against the computer or multiplayer against friends over the Internet. Each player takes on the role of a prospector seeking a substance called amberfell which not only is incredibly valuable but has amazing properties too. To gather it they need to build tools and machines to help them and hinder their opponents. This is set against a backdrop of a wilderness world populated with dangerous creatures and natural hazards. You can read more about my ideas for it on the kickstarter page.

You might ask why I am seeking to fund this through kickstarter and why now? The simple answer is that Kickstarter have just launched in the UK, literally just a couple of weeks ago. Earlier this year I looked into signing up with them but was stymied by their restriction to US bank accounts. I looked at a couple of other similar services, but Kickstarter has the biggest audience and numbers matter for crowdfunding.

Also, running crowdfunding project for a game of like this isn’t really about raising the money, it’s about gauging audience demand. I could continue to develop the game in my spare time and launch it in 12-18 months time but this way I get to find out if anyone is actually interested in the game much sooner. I’m hoping to get some feedback on my ideas: does it capture the imagination; does it sound like fun; would you pay for it and if not, what would you pay for?

If i don’t get over 100 backers then it’s going to be a clear signal that the game doesn’t light any fires and I’d better rethink it. I might still continue with it just because it’s a game I want to play myself, or I may radically shift it. For me, that’s the most exciting part!

I’m tweeting about the game and the funding drive on amberfell’s twitter account so follow me there to keep up to date.

Here’s a quick video of the game in action so far:

I’d love to have your feedback on the game, even if it’s something you would never buy yourself. I want to hear your opinions and thoughts on it. Please leave a comment here or head over to the Kickstarter page and tell me there. If you are also able to donate to the development fund then that would be wonderful – thank you! You can get a copy of the game as a reward or even get a likeness of you built into the game and playable by (hopefully) tens of thousands of people around the world! :)

For what its worth, I do think Assange is being targetted by government forces and they will smear and discredit him. For the UK to hint at changing the status of the Ecuadorian embassy, however diplomatically put, adds some credence to the conspiracy theories that abound. After all, in 1984 PC Yvonne Fletcher was murdered by someone in the Libyan Embassy and the Thatcher government didn’t threaten to revoke the embassy’s status. Assange, by comparison, is a man wanted for extradition on suspicion of rape and other sexual offences. It seems to me that someone somewhere is leaning heavily on the UK government and I don’t think it’s Sweden.

I read a profile of Assange a few years ago that said he’d put himself forward to be the figurehead for Wikileaks, to take all the flak. Presumably he felt his past was clean enough and that there was nothing for the media, or intelligence agencies, to dig up. Now, with the allegations against him in Sweden, that tactic has run its course and he needs to face up to them and return to Sweden to face due process. Its possible that the charges he faces have been engineered by a hostile agency but until he demonstrates that in a court he remains an alleged sexual offender. If he fears for his political freedom in Sweden then he should seek asylum once he’s there. By seeking it here in the UK he reinforces the view that he is avoiding the rape allegations rather than some kind of extraordinary rendition.

Wikileaks for its part needs to distance itself from him completely. His involvement and leadership has been valuable but it’s over now. The longer Wikileaks retains its association with Assange the less credible it becomes.

Wish there was a way to match a half-remembered plotline of a book read years ago with a title. Maybe need to ask an (old) librarian — Ian Davis (@iand) July 13, 2012

That piqued my friends’ interests and so I followed up with an example of a book I have been trying to recall for a few years:

@ldodds not even half remembered really. 2 kids meet man. He is ill. He is from moon, and needs sulphur. Kids work it out by smell of eggs — Ian Davis (@iand) July 13, 2012

Literally minutes later I got two responses pointing to the book I so badly remembered from my childhood:

@iand @ldodds sound like mushroom planet en.wikipedia.org/wiki/The_Wonde… — Rob Styles (@mmmmmrob) July 13, 2012

@iand This? en.wikipedia.org/wiki/The_Wonde… — Leigh Dodds (@ldodds) July 13, 2012

The book turned out to be called The Wonderful Flight to the Mushroom Planet by Eleanor Cameron and had been written in 1954 (I obviously read a much later reprint :) ). It turns out I had remembered the plotline fairly well considering I probably read it in the late seventies:

When two boys find a mysterious ad in a newspaper asking for two young boys to build a spaceship, they quickly construct one out of old tin and scrap wood, and bring it to the advertiser. This man is the mysterious Mr. Bass, a scientist living in an observatory who goes unnoticed by most of the townspeople for some reason. He shows the boys a previously undetected satellite of the earth, the eponymous planet, that can only be seen with a special filter he has concocted. He gives them some special fuel he invented to power their spaceship, and tells them to fly to the mushroom planet (after getting their parents’ permission). He warns them that their trip will only be successful if they bring a mascot.

When it is time for launch, they grab a hen at the last moment for a mascot, and rocket into space. They wake up on the mushroom planet, a small, verdant world covered in soft moss and tree size mushrooms. They quickly meet some residents of the mushroom planet, small men with large heads and slightly green skin, the cousins of the mysterious Mr. Bass. They tell the boys that their planet has had a crisis and everyone is slowly dying. The boys meet up with the king of the planet, the Great Ta, and end up solving the natives’ problem, before returning to Earth.

The mushroom people’s crisis was a lack of sulfur. They resolved this with their mascot hen, as chicken eggs have a high sulfur content.

It turns out that there are 5 further books in the series, so I’m thinking of hunting them down. As I was exploring around wikipedia I spotted that Eleanor Cameron was noted for having had a very public argument with Roald Dahl, criticising Charlie and the Chocolate Factory. The letters that she, he and various others wrote are preserved on the web in the archives of Horn Book Magazine. Here’s their introduction to the furore:

In an article that began in October 1972 and continued in our next two issues, Eleanor Cameron criticized the theories of Marshall McLuhan, whose writings on media were much debated at the time, and decried what she saw as their expression in Charlie and the Chocolate Factory by Roald Dahl. Mr. McLuhan never responded, but Mr. Dahl fired back. So did many of our subscribers. Paul Heins, then editor, periodically refereed.

Her criticism was biting:

What I object to in Charlie is its phony presentation of poverty and its phony humor, which is based on punishment with overtones of sadism; its hypocrisy which is epitomized in its moral stuck like a marshmallow in a lump of fudge — that TV is horrible and hateful and time-wasting and that children should read good books instead, when in fact the book itself is like nothing so much as one of the more specious television shows. It reminds me of Cecil B. De Mille’s Biblical spectaculars, with plenty of blood and orgies and tortures to titillate the masses, while a prophet, for the sake of the religious section of the audience, stands on the edge of the crowd crying, “In the name of the Lord, thou shalt sin no more!”

Dahl responded to her criticisms in forthright style:

I would dearly like to see Mrs. Cameron trying to read Little Women, or Robinson Crusoe for that matter, to a class of today’s children. The lady is completely out of touch with reality. She would be howled out of the classroom. She also says, “I should like to travel up and down the country going to elementary schools and saying to all the teachers: Find out about the good children’s books.” I myself would like very much to hear what the teachers’ replies would be if the patronizing, all-knowing Mrs. Cameron ever tried to do this. The hundreds of letters I get every year from American teachers tell me that they are on the whole a marvelous lot of people with a wide knowledge of children’s books. It is an enormous conceit for Mrs. Cameron to think that her knowledge is greater than theirs or her taste more perfect.

However, her criticisim had a lasting effect, as she objected to the portrayal of the Oompa Loompas:

Brought directly from Africa, the Oompa-Loompas have never been given the opportunity of any life outside of the chocolate factory, so that it never occurs to them to protest the possibility of being used like squirrels.

This ultimately led to the revision of the US edition of the book, changing the depiction of Oompa Loompas from native African figures to more acceptable dwarves:

While researching this post I came across a good academic article on these changes: Charlie and the Chocolate Factory;Versions and Changes by Dominic Cheetham.

Amazing how an innocent memory of a childhood book can take you down a rabbit hole of controversy!

I recently finished re-reading The Pleasure of Finding Things Out which is a diverse collection of Richard Feynman’s writings and talks. To be frank, the book is a bit of a mixed bag: there are some great pieces in there and some not-so-great ones. To get a real picture of the man you have to read a lot more of his works and watch the various videos of him at work. He was irreverent, chaotic and misogynistic by today’s standards, but above all that he was human and had humanity.

This time round I read it on the kindle which let me collect together a series of notes and extracts from the book, nicely collated online for me by Amazon. This is a new experience for me because I have never marked or annotated a paper book in my life (I treasured them so much as a child). Being able to mark text on the Kindle is liberating for me personally. All the quotes in this post are ones I gathered while reading The Pleasure of Finding Things Out.

I think Feynman stands as one of science’s greatest teachers and communicators. He had true insight into what it meant to be a scientist, worlds away from the dry “scientific method” philosophy of Popper and others. His philosophy was grounded in the real world (and how he would hate to be spoken of as having a philosophy!). His most succinct definition of science was:

Science is the belief in the ignorance of experts.

Central to his conception of science was the right to doubt:

It is our responsibility as scientists, knowing the great progress and great value of a satisfactory philosophy of ignorance, the great progress that is the fruit of freedom of thought, to proclaim the value of this freedom, to teach how doubt is not to be feared but welcomed and discussed, and to demand this freedom as our duty to all coming generations.

This strikes at the heart of religion in his view which is based on faith, not doubt. Referring to Galileo among others he says:

Our freedom to doubt was born of a struggle against authority in the early days of science.

He was comfortable with the notion of not understanding the world completely, of not having an explanation for everything. This is something I deeply share with him and why I feel such an affinity to him. The popular perception of scientists is that they are on a search for meaning, trying to understand why we are here, what our purpose is. That is entirely a false perception but it’s one that has come to the fore again with the popular coverage of the search for the Higgs boson. It’s presented as the ultimate goal, the God particle, the reason why things are as they are and yet it is none of these things.

In his words:

I don’t have to know an answer, I don’t feel frightened by not knowing things, by being lost in a mysterious universe without having any purpose,

and…

I can live with doubt and uncertainty and not knowing. I think it’s much more interesting to live not knowing than to have answers which might be wrong.

For him, uncertainty and doubt were the heart of the process:

We must discuss each question within the uncertainties that are allowed. And as evidence grows it increases the probability perhaps that some idea is right, or decreases it. But it never makes absolutely certain one way or the other. Now we have found that this is of paramount importance in order to progress. We absolutely must leave room for doubt or there is no progress and there is no learning. There is no learning without having to pose a question. And a question requires doubt. People search for certainty. But there is no certainty.

As Feynman would have it, scientists do what they do for the pleasure of finding things out, not for some spiritual search for complete understanding. On receipt of his Nobel Prize he said:

The prize is the pleasure of finding the thing out, the kick in the discovery, the observation that other people use it [my work]-those are the real things, the honors are unreal to me.

At the core of this all was his conviction that the scientific process arose out of integrity and that society had a duty to investigate and pursue the facts:

It might be true that you can be cured by the miracle of Lourdes. But if it is true it ought to be investigated. Why? To improve it. If it is true then maybe we can find out if the stars do influence life; that we could make the system more powerful by investigating statistically, scientifically judging the evidence objectively, more carefully. If the healing process works at Lourdes, the question is how far from the site of the miracle can the person, who is ill, stand? Have they in fact made a mistake and the back row is really not working? Or is it working so well that there is plenty of room for more people to be arranged near the place of the miracle? Or is it possible, as it is with the saints which have recently been created in the United States-there is a saint who cured leukemia apparently indirectly-that ribbons that are touched to the sheet of the sick person (the ribbon having previously touched some relic of the saint) increase the cure of leukemia-the question is, is it gradually being diluted? You may laugh, but if you believe in the truth of the healing, then you are responsible to investigate it, to improve its efficiency and to make it satisfactory instead of cheating.

He was pragmatic not an idealist. He understood that the curiosity he sought was not pervasive throughout society:

an interesting question of the relation of science to modem society is just that-why is it possible for people to stay so woefully ignorant and yet reasonably happy in modem society when so much knowledge is unavailable to them?

He lamented that society was not scientific, and science was relegated to the backroom:

The value of science remains unsung by singers, so you are reduced to hearing-not a song or a poem, but an evening lecture about it. This is not yet a scientific age.

For a period of his life he investigated the teaching of science in schools, recognising that children were not being taught that it was ok to be curious, to doubt or to experiment, traits that were essential to his vision of a scientific society. Instead they were being taught to remember definitions of things without understanding. In reference to a textbook that claimed that energy is what makes a dog walk or a car move he said:

I finally figured out a way to test whether you have taught an idea or you have only taught a definition. Test it this way: You say, “Without using the new word which you have just learned, try to rephrase what you have just learned in your own language.” “Without using the word `energy,’ tell me what you know now about the dog’s motion.” You cannot. So you learned nothing except the definition. You learned nothing about science.

And, just as it’s not art to know the difference between an HB and a 3B pencil he stated:

It is not science to know how to change centigrade to Fahrenheit. It’s necessary, but it is not exactly science.

As I wrote at the start, I don’t really consider Feynman a hero in the normal sense of the word. There is much I don’t like about his personality and attitude, but I entirely respect his integrity. He was what he was. Much of what he said and wrote resonates with me and influences how I bring up my children. I teach them to doubt, to challenge,  to question and above all believe in the ignorance of experts.

Separated at birth?

The statue is of Isambard Kingdom Brunel who designed the station (and half the rail network of England) and sported a fetching array of top hats. Henceforth the character in Amberfell shall be known as “The Engineer”.

In my opinion the Go designers have done an excellent job of blending the flexibility and convenience of a scripting language with the performance and safety of a strongly typed compiled language. Coupled with its special support for concurrency and excellent standard library this makes Go a great language to work with. The amazing speed of the compiler means the development cycle is a fast as a scripting language even though full optimizations are always switched on.

Go recently reached version 1.0 which is intended to remain stable for a number of years to come.

Syntax

Go is a small language in the vein of C, easy to learn the basics in a couple of hours. The language specification is under 23,000 words long and there are only 25 reserved keywords. As an example, there is no separate while or do constructs, they are both collapsed into a simpler for:

for condition {
    function()
}

The language designers have done a good job at removing extraneous cruft and boilerplate. The most obvious is the absence of semicolons. The only time you need to use them is when you want multiple instructions on one line. Otherwise you can simply leave them off the end of lines. It sounds trivial but it really enhances readability and eliminates a range of stupid typo errors you see in other languages. Another welcome cruft-removal is the loss of parantheses around conditions in if statements.

Variable declaration uses the var keyword followed by the name and type of the variable and optionally an initializing value. However, if you have an initializing value then you can simply assign it and the compiler works out the type for you. In the following both foo and bar are of type float64:

var foo float64 = 1.5
bar := 1.5

One thing I thought was odd at first was that the capitalisaton of a function determines its visibility outside of a package. Functions (and variables) that start with a capital letter are visible, those starting with a lower case letter are package local. When I first saw that I was disappointed since it made me think of FORTRAN. However in practice it’s not been a problem at all and is a really simple convention that again removes the cruft of having to mark things as explicitly private or public.

This leads me onto the next point: Go is opinionated about its formatting, for example in the placement of braces in an if/else block. A lot of people will recoil from this, getting precious about where they should put their braces and how many spaces to use as an indent. However, if you’ve programmed in Python then you’ll be used to significant formatting. My advice is simply to let go of your prejudices and Go with the flow (!!). The benefits of consistent formatting really pay off. Enforcing a brace placement style and other conventions means the compiler can be super fast.

It also means that Go can ship with a built-in code prettifier so all the Go code you ever deal with will have a consistent format and layout. Just run go fmt in your package directory. I run it as part of my git commit.

Packaging

Packaging in Go is simple and powerful and borrows heavily from Python but with the unique twist that it’s web-aware. Standard packages are imported by name and there’s no concept of importing a single name from a package. Names imported from a package are accessed by using the last component of the package name as a prefix (rather than the horrendous full package prefix that you often see in Java and similar languages)

import "math"
import "fmt"
import "image/color"

x := color.RGBA{255, 255, 255, 0}

However you can also import web-accessible packages by specifying a portion of their URL:

import "github.com/banthar/gl"
x := gl.Init()

You can install that package by running

go get github.com/banthar/gl

which tells Go to check out the package from github automatically for you. It will also follow any dependencies it finds and fetch those for you automatically. This means there are no separate configuration files to describe dependencies – it’s right there in the code. In fact the “Go Way” to distribute your packages is by hosting it in a code repo, in the canonical file structure. Go understands Mercurial, Git, Bazaar, Subversion plus a recent patch uses a meta tag in an HTML page to specify a repo to use.

This is great for distributed development and it bakes into the core language some of the learnings from other language ecosystems (gems, maven, pip etc).

Anti Features

The features of Go such as goroutines and garbage collection are pretty well known so I thought I’d focus on what I think are important anti-features, i.e. things that have deliberately not been added.

The first of these is trivial: there are no warnings in the compiler, only errors. Your code is either good to go or it isn’t. Black or white. Warnings are a symptom of an indecisive language and Go is firmly decisive and forces the developer to decide on a solution. Most compiler warnings are bugs waiting to happen.

The second is no dynamic linking (of other Go code, you can link to C libraries). That really bucks the trend of modularity in modern development. However, here’s the point: dependency is a synonym for modularity. If your modules aren’t controlled at runtime then neither are your dependencies, and likely as not, nor are their dependencies. This implies that a well-meaning upgrade of a library or a jar can cause unintended consequences and so requires a large integration testing cost for every upgrade. How many services have you seen that have been running for months or years with their own local copies of libraries so other services on the box can be upgraded without paying the cost of retesting the first service? Static linking means you compile the service and deploy it. End of job.

The third is no exceptions. This is highly controversial in many circles, but I’ve long held the opinion that exceptions are broken by design because they force errors to be handled at points far away from the cause. How many codebases contain the following:

catch (e Exception) { 
    // TODO: figure out what to do here
}

Or you get detailed exceptions thrown that bubble up implementation details to the outside world. For example, you thought you’d encapsulated the fact that your IO was running over a network or a local disk but now you main application loop needs to know what to do when the DNS server goes away.

Go replaces exceptions with return values, but since Go functions can return multiple values these are in addition to the normal return value(s). Go provides the very neat defer keyword that takes the place of final sections, ensuring that code is run no matter what happens in the function. Still not convinced? Read what the architect of ZeroMQ has to say on the subject.

Those first three anti-features are aimed at making Go into a language suitable for building robust, large scale systems. There are no warnings so there are fewer hidden bugs waiting to bite you. Deployment and dependency management is simpler and therefore cheaper. Code is more robust because you’re forced to deal with errors close to where they occur and where you have the most information about the problem. The final anti-feature is a little different and probably even more controversial than lack of exceptions.

Go is not object-oriented. This, in my opinion, is a massive plus for the language. I can hear the die-hards screaming already about encapsulation, inheritance and polymorphism. It turns out that these things are not as important as we once thought. I’ve spent a decade working closely with RDF and structured data in general and I came to the conclusion several years ago that OO was simply the wrong paradigm for the real world. In the real world, things are fuzzy and they spread across multiple conceptual boxes all at once. Is it a circle or an ellipse? Is she an employee or a homeworker? Classifying things into strict type hierarchies, although seductive, is never going to work. In RDF we’re more than happy for a thing to have multiple types (a person, a woman, an employee, a researcher, an adult) with varying properties (name, age, gender, workplace, height) that may or may not apply to any or all of the types.

It’s human instinct to classify things into buckets based on what they look like but that instinct is wrong. Instead we should treat things by how they behave and this is the essence of Go’s approach. Idiomatic Go is oriented around interfaces that specify behaviour. If a type implements the methods in the interface then it can be used wherever the interface is required. However, the smart bit is that unlike Java interfaces, in Go you don’t need to declare which interfaces you implement: the compiler just works it all out for you.

This is duck typing on steroids because it’s strongly typed so it’s all checked at compile time rather than runtime. It’s as powerful as the duck typing in a dynamic language like Python or Ruby but it catches stupid errors such as calling a method with the wrong number of arguments or passing a string when a float is needed.

As an example, in Amberfell I have a TimedObject interface which is very simple:

type TimedObject interface {
	Update(dt float64) bool
}

Anything that has a method with that signature can be used where I need a TimedObject, e.g. my Furnace type:

func (self *Furnace) Update(dt float64) (completed bool) {
  // burn some coal and smelt the ore
}

I maintain a list of things that need to be regularly updated and getting something into that list is simply a matter of writing the Update function for it.

There’s a performance advantage of not having inheritance in Go. Instead of a vtable that is traversed hierarchically at runtime for every call, Go has a static sorted list of methods for a type and a static sorted list of methods for the receiving interface and it simply runs down each list in parallel to determine if the type meets the interface or not.

Developer support

In the interests of actually finishing this post and retaining a chance of people reading it, I’m going to wrap up by talking about some of the developer support that’s available.

One of the most useful tools is the Go playground. This is a web-based Go environment that you can use to test code and share with others. Just like pastebin it gives you a short URL for a code snippet but let’s you run that code in-place. This is invaluable when learning, especially when asking question on the golang-nuts mailing list or on StackOverflow. The fact that everyone is discussing the same code and everyone can see that the code actually compiles and runs makes for much quicker answers.

Another invaluable tool is Gary Burd’s gopkgdoc, a documentation server. It takes advantage of Go’s built-in web based package management to generate documentation for Go packages. For example, here is the documentaton for the github.com/cznic/mathutil package: http://go.pkgdoc.org/github.com/cznic/mathutil, or for the standard image package: http://go.pkgdoc.org/image. I have it set up as a short search keyword in firefox so I can just type “go math” to get the documentation for the math package. The standard package library is very comprehensive.

If you’re learning go then there’s a good set of graded learning materials. Start with the Go Tour which is an interactive tour through the language with an embedded Go compiler so you can try the code out as you learn. Then you can progress onto the interactive code walkthroughs such a Channels and Goroutines or First Class Functions. Once you’ve got into actually writing code, the Effective Go document provides an overview of common idioms and practices and the language specification is very readable once you’re regularly using the language.

Finally, there are a couple of books that could be useful: Programming in Go by Mark Summerfield and A Complete Introduction to Go by Miek Gieben.

Update: Follow the discussion on Reddit and Hacker News

I made a few other changes today. Blocks now have an alignment so they remain facing the way you place them. Also they have persistent damage so you can hit a block a few times to weaken it (and it grows cracks all over it) then come back later to finish it off. That’ll be useful when things are trying to break down your walls and steal your Amberfell.

• Find an Amberfell source
• Mine some stone, craft the rubble into stone bricks and use them to construct a furnace and a forge
• Mine some coal
• Mine some copper ore and use it with some coal in the furnace to make copper ingots
• Mine some zinc ore and use it with some coal in the furnace to make zinc ingots
• Use the copper and zinc ingots in the forge to make brass ingots
• Use the brass ingots in the forge to make brass plates
• Cut some trees and make a carpenter’s bench
• Use the carpenter’s bench to make some planks from tree trunks
• Find and kill some wolves to obtain leather
• Find and open some bees nests to get some beeswax
• Use the brass plates, leather, beeswax and planks to make an Amberfell pump, place this on the Amberfell source
• Find some quartz and use the furnace to convert it into glass
• Use the glass and some planks to make an Amberfell condenser
• Cut some trees to make firewood
• Take the Amberfell from the pump and place it in the condenser with some firewood.
• Wait a bit and hey presto you’ve created your first Amberfell crystal!

Amberfell pumps are very slow, so you can speed them up by building a Steam Generator and placing it next to the pump. To create the steam generator:

• Mine some coal
• Mine some iron ore and use it with the coal in a furnace to make iron ingots
• Use the iron ingots in the forge to make iron plates
• Mine some copper and use it with the coal in a furnace to make copper ingots
• Use the copper ingots in the forge to make copper plates
• Mine some stone, craft the rubble into stone bricks
• Constuct a steam generator from the iron plates, copper plates and stone bricks

You can make all the above right now but I have a few ideas for the future. Furnaces are quite slow but you’ll be able to speed them up by adding a steam generator to turn them into blast furnaces. Also checking the amberfell pump and taking the amberfell to the condenser every few minutes is tedious. You’ll be able to construct piping that will carry the Amberfell automatically from a pump to a condenser. The fluid flow logic for this has all been worked out and coded by Kier and I just need to integrate it into the game. Also Amberfell is a mysterious substance and has some other hidden properties that you’ll be able to take advantage of.

It’s quite fun like that and a lot easier to control. However, I’m sticking with the isometric viewpoint for now because I think it’ll look good when you start building your own automatons.