Hotel - A Programming language
author: Onne Gorter
Hotel's main goal is to enable high level programming. Hotel is itself a high level language, but it also enables creating "more higher" levels. It can claim to do this because it solves a very important problem holding other languages back: global effects. Hotel simply does not have them.
Why is this important? Any kind of global effect cannot be isolated. You can use them inside of functions or objects, but that does not hide them (they are global after all). It might be convenient, but it is not an abstraction, and therefore it does not create a higher level. You still have to document the effect, and handle that function or object as special. Effectively you must create usage patterns around the global effects.
What are these global effects? Usually, doing io (files/network/syscalls), defining classes, loading modules, threads (if they share), blocking, resources, singletons and (mutable) globals.
Hotel does not permit any of these. More specifically, it allows all of them, but in such a way they do not have global effects. Hotel only affords two global effects:
- computation takes time and memory;
- blocking a computation waiting for the outside world (io). The first is assumed to be available in abundance, and thus not a problem in the common case. The second is a tradeoff, not allowing blocking is also a global effect. But blocking makes io the same as a computationally heavy algorithm, you document that fact, and allow the programmer to choose its impact by making it easy to do the io (or heavy computation) in the background.
Note, usually (pure) functional programming is put forward as a solution to the above problem. But it cannot be, because it does not allow you to hide the side effects, thus the side effects become global effects. Pointed out clearly; definitely is a good thing. But it disallows creating abstractions around side effects, the best you can get is create conveniences.
a = "hello" b = "world" print(a, b)
Outputs "hello world" on the console,
b are not so much variables, but
immutable name bindings. Hotel supports mutations, but you have to ask.
var x = 0 "hello world".split.each: word -> x += word.size print x
Outputs 10. While not a bad solution, it can also be written without mutability:
"hello world".split.map(word -> word.size).sum
The choice is yours. But hotels default choices are immutable. Like in this
String.split returns a
List which is an immutable. Much like
Strings in most languages.
As a last example:
page = html.parse(http.get("http://en.wikipedia.org/wiki/Hotel")) print(page.find("p").text)
Which will print the first page of the wikipedia article on hotels. (Not this language, haha).
Hotel is in early stages. It is still missing real classes (can be simulated), and many other features and things you'd expect.
Also hotel has no illusion of being fast.
Hotel - The Name
It is called hotel for a reason. You came here to solve your problem. Hotel, the programming language, does the chores and housekeeping for you. So you can focus on the problem at hand.
hotel |hōˈtel| noun
- an establishment providing accommodations, meals, and other services for travellers and tourists.
- a code word representing the letter H, used in radio communication.
- a programming language providing many services for programmers and developers.
(Please ignore the CMakeFiles.txt, it is a project description for IDEs.)
requires libgc (aka boehmgc or bdw-gc) optionally libopenssl, portaudio, cairo + libjpeg and for a graphics environment, either gtk or cocoa
make sudo make PREFIX=/usr install
That will install a
tl command, the main interpreter. Also a
that last one is for opening windows in a desktop environemnt.
To disable building certain parts, you can use:
a headless install:
make NO_PORTAUDIO=1 NO_GRAPHICS=1 sudo make NO_PORTAUDIO=1 NO_GRAPHICS=1 PREFIX=/usr install
xcode-select --install brew install bdw-gc cairo portaudio make BUILD=release install
The MIT License (MIT)
Copyright (c) 2015 Onne Gorter
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.