Fabulous adventures in coding

You are on what used to be a large lake, but which is now a large mud pile. There are “shores” to the north and south. Half-buried in the mud is an old trunk, bulging with jewels. A suspicious-looking individual … Continue reading →

This was the maintenance room for Flood Control Dam #3. Apparently, the room has been ransacked, for most of the valuable equipment is gone. On one wall is a group of buttons colored yellow, brown and red. The only doorway … Continue reading →

You are atop Flood Control Dam #3, which was once quite a tourist attraction. There are exits to the northeast and west, and a scramble down. The sluice gates on the dam are closed. Behind the dam is a wide … Continue reading →

You are south of a large lake, far too deep and wide to be crossed. Paths lead east, south and southwest. > go north You would drown. > swim in the lake Swimming isn’t allowed in the lake. > go … Continue reading →

This was once an artist’s studio. The walls are splattered with paints of 69 different colors. To the west is a doorway (also covered with paint). A dark and narrow chimney leads up from a fireplace; although you might be … Continue reading →

This is a sand-filled cave whose exit is to the southwest. > dig in the sand with the shovel You seem to be digging a hole here. > again The hole is getting deeper, but that’s about it. > again … Continue reading →

You are near the top of Aragain Falls. The only path leads north. A solid rainbow spans the falls to the west. > go north Sandy beach You are on a large beach on the east shore of the river, … Continue reading →

You are on a small, rocky beach by the Frigid River, below the falls. A rainbow crosses over the falls to the east and a narrow path continues to the southwest. > go east Can you walk on water vapor? … Continue reading →

You are atop the west wall of a great canyon, offering a marvelous view of the mighty Frigid River below. Across the canyon, the walls of the White Cliffs join the mighty ramparts of the Flathead Mountains. To the north, … Continue reading →

I am spending the week at FB headquarters in Menlo Park: (That’s me looking out for the thief. He’s around here somewhere.) I assume that the axe-wielding troll had already been killed and turned into mist, since the room was … Continue reading →

Paths lead into the forest to the west and northwest. Also, a well-marked path extends east. > go west Forest This is a dimly lit forest, with large trees all around. > go west Behind House > enter the white … Continue reading →

Standing by the temple’s altar, you can see a small hole in the floor which leads into darkness. The rest of the temple is north of here. On the two ends of the altar are burning candles. On the altar … Continue reading →

This looks like an Egyptian tomb. A stair ascends to the west. The solid-gold coffin used for the burial of Ramses II is here. > take the coffin Your load is too heavy. > drop the sword Dropped. > take … Continue reading →

This is a large domed temple. A piece of rope descends from the railing of the dome, about 20 feet above, ending some five feet above your head. On the east wall is an ancient inscription, probably a prayer in … Continue reading →

You are at the periphery of a large dome, which forms the ceiling of another room below. A wooden railing protects you from a precipitous drop. > tie the rope to the railing The rope drops over the side and … Continue reading →

This is a circular room with passages in all directions. Several have unfortunately been blocked by cave-ins. > go southeast Last time we implemented the state transition function; it takes in a zchar and a state, and produces a string … Continue reading →

This is a small room with passages to the east, northeast and south, and a forbidding hole leading west. Bloodstains and deep scratches (perhaps made by an axe) mar the walls. A troll, brandishing a bloody axe, blocks all passages … Continue reading →

You are in a dark, damp cellar with narrow passageways to the north and east. On the west is the bottom of a steep metal ramp which is unclimbable. > go north We are very close to being able to … Continue reading →

You have moved into a dark place. It is pitch black. You are likely to be eaten by a grue. > what is a grue The grue is a sinister, lurking presence in the dark places of the earth. Its … Continue reading →

The living room opens to the east. To the west is a wooden door, above which is strange gothic lettering. The door is nailed shut. There is a trophy case here, and a large oriental rug in the center of … Continue reading →

You are in the kitchen of the white house. A table has recently been used for the preparation of food. A passage leads west and a dark staircase leads upward. A chimney leads down and to the east is a … Continue reading →

You are behind the white house. Paths lead into the forest to the east and northeast. In one corner of the house is a small window which is slightly ajar. > examine the window The window is slightly ajar, but … Continue reading →

You are ten feet above the ground, nestled among large branches. Beside you on the branch is a small bird’s nest. In the bird’s nest is a large egg encrusted with precious jewels, apparently scavenged by a childless songbird. > … Continue reading →

Well here’s something I never thought I’d write in Fabulous Adventures in Coding when I started this blog more than ten years ago: Today is my first day at Facebook. It still feels weird to say it. But as it … Continue reading →

This is a path through a dimly lit forest, curving from south to east. A large tree with low branches stands by the edge of the path. On the ground is a pile of leaves. > count the leaves 69,105. … Continue reading →

> go north You are facing the north side of a white house. There is no door here, and all the windows are boarded up. A narrow path winds north through the trees. > go north Let’s start with some … Continue reading →

You are standing in an open field west of a white house, with a boarded front door. You could circle the house to the north or south. There is a small mailbox here. > open the mailbox Opening the small mailbox reveals … Continue reading →

Thanks to everyone who came out to my beginner talk on using functional style in C# on Wednesday. I had a great time and we had a capacity crowd. The video will be posted in a couple of weeks; I’ll put up a … Continue reading →

Many years ago I awoke in the dead of night in a cold sweat, with the certain knowledge that a close relative had suddenly died. […] In fact, the relative is alive and well […]. However, suppose the relative had in … Continue reading →

Happy New Year everyone; I hope you had a pleasant and relaxing festive holiday season. I sure did. I’m starting the new year off by giving a short — an hour long or so — talk on how you can … Continue reading →

I said last time that binary-searching the rationals (WOLOG between zero and one) for a particular fraction that is very close to a given double does not really work, because we end up with only fractions that have powers of … Continue reading →

All right, we have an arbitrary-precision rational arithmetic type now, so we can do arithmetic on fractions with confidence. Remember the problem I set out to explore here was: a double is actually a fraction whose denominator is a large … Continue reading →

A couple of years ago I developed my own arbitrary precision natural number and integer mathematics types, just for fun and to illustrate how it could be done. I’m going to do the same for rational numbers here, but rather … Continue reading →

Good Monday morning everyone; I hope my American readers had a lovely Thanksgiving. I sure did! Well enough chit-chat, here’s a problem I was pondering the other day. We know that doubles introduce some “representation error” when trying to represent … Continue reading →

In the previous exciting episode I ended on a cliffhanger; why did I put a loop around each wait? In the consumer, for example, I said: while (myQueue.IsEmpty) Monitor.Wait(myLock); It seems like I could replace that “while” with an “if”. … Continue reading →

Locks are tricky; I thought today I’d talk a bit about some of the pitfalls of locking that you might not have seen before. As you probably know, the lock statement in C# is a syntactic sugar for the use … Continue reading →

One of the early stumbling blocks people run into when learning traditional Aristotelian logic is the idea that “a false proposition implies any proposition”. Let’s briefly review material implication, and then I’ll talk about what the implications of material implication … Continue reading →

UPDATE: A commenter points out that today is the 200th anniversary of the birth of George Boole; I had no idea when I scheduled this article that it would be so apropos. Happy birthday George Boole! Here’s a little-known and … Continue reading →

A question I occasionally get is, suppose I have code like this: const double x = 200.0; const double y = 0.5; ... void M(double z) { double r = z * x * y; ... Does the compiler generate … Continue reading →

In part one I gave a bunch of reasons to reject the proposed feature where the compiler infers additional type information about a local variable when inside the consequence of a conditional statement: if (animal is Dog) { animal.Bark(); // … Continue reading →

I am excited to announce that Essential C# 6.0 is now available in stores! As always, Mark did the vast majority of the work. And as always, I was delighted to be asked once again to contribute to one of … Continue reading →

In last week’s episode of FAIC I was discussing code of the form: if (animal is Dog) ((Dog)animal).Bark(); Specifically, why the cast was illegal if the variable tested was of generic parameter type. Today I want to take a bit … Continue reading →

Here’s a question I’m asked occasionally: void M<T>(T t) where T : Animal { // This gives a compile-time error: if (t is Dog) ((Dog)t).Bark(); // But this does not: if (t is Dog) (t as Dog).Bark(); } What’s going … Continue reading →

One of the C# oddities I noted in my recent article was that I find it odd that creating a numeric type with less-than, greater-than, and similar operators requires implementing a lot of redundant methods, methods whose values could be … Continue reading →

I got a lot of great responses to my recent piece on features of C# I somewhat regret; thanks all for those. As promised, today on fun-for-Friday-FAIC I’ve posted some fabulous adventures in nature photography from my recent trip to … Continue reading →

Hey everyone, I am finally back from my many travels this summer and looking forward to doing some blogging this autumn. I’ll post some vacation photos when I have them sorted out. Until then, here’s an article that the nice … Continue reading →

I have begun my travels but I have one more from the road. Literally! The nice people at radar asked me to write them a short article on static analysis for beginners; I was happy to oblige. (There seem to … Continue reading →

A quick note: I’m going to be traveling for much of the rest of June and I haven’t got articles queued up, so the blog will go dark for a bit; see you in July! In the last two episodes … Continue reading →

Last time on FAIC I reran my 2004 article on tips for coding on whiteboards for interviews. This time, a rerun from 2009 article on a similar topic. Next time, some more thoughts on this subject. Interviewing job-seeking candidates is … Continue reading →