6206 - mu - Soul of a tiny new machine. More thorough tests → More comprehensible and rewrite-friendly software → More resilient society.

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author	Kartik Agaram <vc@akkartik.com>	2020-04-17 01:33:51 -0700
committer	Kartik Agaram <vc@akkartik.com>	2020-04-17 01:33:51 -0700
commit	11f7f7b8122f1c0c639ce8921278b1924bc51b20 (patch)
tree	0816a8097e7f6fbd5d33607ad915c656b8f85b02 /init.linux
parent	d6f9813650d1e09c23b5a9eebb22684175f73464 (diff)
download	mu-11f7f7b8122f1c0c639ce8921278b1924bc51b20.tar.gz

6206

Diffstat (limited to 'init.linux')

0 files changed, 0 insertions, 0 deletions

//: You guessed right: the '000' prefix means you should start reading here. //: //: This project is setup to load all files with a numeric prefix. Just create //: a new file and start hacking. //: //: The first few files (00*) are independent of what this program does, an //: experimental skeleton that will hopefully make it both easier for others to //: understand and more malleable, easier to rewrite and remould into radically //: different shapes without breaking in subtle corner cases. The premise is //: that understandability and rewrite-friendliness are related in a virtuous //: cycle. Doing one well makes it easier to do the other. //: //: Lower down, this file contains a legal, bare-bones C++ program. It doesn't //: do anything yet; subsequent files will contain :(...) directives to insert //: lines into it. For example: //: :(after "more events") //: This directive means: insert the following lines after a line in the //: program containing the words "more events". //: //: A simple tool is included to 'tangle' all the files together in sequence //: according to their directives into a single source file containing all the //: code for the project, and then feed the source file to the compiler. //: (It'll drop these comments starting with a '//:' prefix that only make //: sense before tangling.) //: //: Directives free up the programmer to order code for others to read rather //: than as forced by the computer or compiler. Each individual feature can be //: organized in a self-contained 'layer' that adds code to many different data //: structures and functions all over the program. The right decomposition into //: layers will let each layer make sense in isolation. //: //: "If I look at any small part of it, I can see what is going on -- I don't //: need to refer to other parts to understand what something is doing. //: //: If I look at any large part in overview, I can see what is going on -- I //: don't need to know all the details to get it. //: //: Every level of detail is as locally coherent and as well thought-out as //: any other level." //: //: -- Richard Gabriel, "The Quality Without A Name" //: (http://dreamsongs.com/Files/PatternsOfSoftware.pdf, page 42) //: //: Directives are powerful; they permit inserting or modifying any point in //: the program. Using them tastefully requires mapping out specific lines as //: waypoints for future layers to hook into. Often such waypoints will be in //: comments, capitalized to hint that other layers rely on their presence. //: //: A single waypoint might have many different code fragments hooking into //: it from all over the codebase. Use 'before' directives to insert //: code at a location in order, top to bottom, and 'after' directives to //: insert code in reverse order. By convention waypoints intended for insertion //: before begin with 'End'. Notice below how the layers line up above the "End //: Foo" waypoint. //: //: File 001 File 002 File 003 //: ============ =================== =================== //: // Foo //: ------------ //: <---- :(before "End Foo") //: .... //: ... //: ------------ //: <---------------------------- :(before "End Foo") //: .... //: ... //: // End Foo //: ============ //: //: Here's part of a layer in color: http://i.imgur.com/0eONnyX.png. Directives //: are shaded dark. //: //: Layers do more than just shuffle code around. In a well-organized codebase //: it should be possible to stop loading after any file/layer, build and run //: the program, and pass all tests for loaded features. (Relevant is //: http://youtube.com/watch?v=c8N72t7aScY, a scene from "2001: A Space //: Odyssey".) Get into the habit of running the included script called //: 'test_all_layers' before you commit any changes. //: //: This 'subsetting guarantee' ensures that this directory contains a //: cleaned-up narrative of the evolution of this codebase. Organizing //: autobiographically allows a newcomer to rapidly orient himself, reading the //: first few files to understand a simple gestalt of a program's core purpose //: and features, and later gradually working his way through other features as //: the need arises. //: //: Programmers shouldn't need to understand everything about a program to hack //: on it. But they shouldn't be prevented from a thorough understanding of //: each aspect either. The goal of layers is to reward curiosity. // Includes // End Includes // Types // End Types // prototypes are auto-generated in the makefile; define your functions in any order #include "function_list" // by convention, files ending with '_list' are auto-generated // Globals // End Globals int main(int argc, char* argv[]) { atexit(teardown); // End One-time Setup // End Commandline Parsing return 0; // End Main } //: our first directive; will move the include above the program :(before "End Includes") #include<stdlib.h> //: Without directives or with the :(code) directive, lines get added at the //: end. :(code) void setup() { // End Setup } void teardown() { // End Teardown }


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