[Mono-devel-list] REPOST: Mono class layout

[Miguel de Icaza]

Hey guys,

   I figured not everyone knows about the Mono class layout, or some of
the conventions used in Mono.  I am posting the file `mcs/class/README'
to the list.

Miguel.
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The class libraries are grouped together in the assemblies they belong.

Each directory here represents an assembly, and inside each directory we
divide the code based on the namespace they implement.

In addition, each assembly directory contains a Test directory that holds the
NUnit tests for that assembly. 

The nant build file for an assembly creates two versions of the dll for that
assembly. One version is a "full" dll.  The full dll contains (almost) all 
of the classes, regardless of how complete the classes are. The name of this
dll is the normal name you would expect, like "corlib.dll" or "System.dll".
These full dll's are created in the /mcs/class/lib directory.

The other dll which is built is a "restricted" dll.  The restricted dll
omits incomplete classes that would prevent the NUnit testrunner from actually
running the tests. These restricted dll's are created in the Test directory
of their respective assembly and named with a "_res" suffix.  So, for example,
the NUnit-testable dll for corlib is /mcs/class/corlib/Test/corlib_res.dll.

The final dll which is built is the one which houses the actual NUnit tests.
This dll is built from all of the classes in the Test directory and below, and
is named with a "_test" suffix. So, for example, the NUnit tests for corlib
are in /mcs/class/corlib/Test/corlib_test.dll. This dll is also linked with 
the restricted dll found in the same directory.


* Missing implementation bits

	If you implement a class and you are missing implementation bits,
	please use the attribute [MonoTODO].  This attribute can be used
	to programatically generate our status web pages:

	[MonoTODO]
	int MyFunction ()
	{
		throw new NotImplementedException ();
	}

* Supporting both .NET 1.1 and .NET 1.0 builds

	Use #ifdef NET_1_1 for code that should only be included for
	a .NET 1.1 build, and NET_1_0 for code that should only be included
	for a 1.0 build.

* Tagging buggy code

	If there is a bug in your implementation tag the problem by using
	the word "FIXME" in the code, together with a description of the 
	problem.

	Do not use XXX or obscure descriptions, because otherwise people
	will not be able to understand what you mean.

* Tagging Problematic specs.

	If the documentation and the Microsoft implementation do
	differ (you wrote a test case to prove this), I suggest that you edit
	the file `mcs/class/doc/API-notes' so we can keep track of these problems
	and submit our comments to ECMA or Microsoft and seek clarification.

	Sometimes the documentation might be buggy, and sometimes the implementation
	might be buggy.  Lets try to identify and pinpoint which one
	is the correct one.

	Sometimes the specification will be lame (consider Version.ToString (fieldCount)
	where there is no way of knowing how many fields are available, making the API
	not only stupid, but leading to unreliable code).

	In those cases, use the keyword "LAMESPEC".
	

* Coding considerations and style.

	In order to keep the code consistent, please use the following
	conventions.  From here on `good' and `bad' are used to attribute
	things that would make the coding style match, or not match.  It is not
	a judgement call on your coding abilities, but more of a style and 
	look call.  Please try to follow these guidelines to ensure prettiness.

	Use 8 space tabs for writing your code (hopefully we can keep
	this consistent).  If you are modifying someone else's code, try
	to keep the coding style similar.

	Since we are using 8-space tabs, you might want to consider the Linus
	Torvals trick to reduce code nesting.  Many times in a loop, you will
	find yourself doing a test, and if the test is true, you will nest.
	Many times this can be changed.  Example:


		for (i = 0; i < 10; i++) {
			if (something (i)) {
				do_more ();
			}
		}

	This take precious space, instead write it like this:

		for (i = 0; i < 10; i++) {
			if (!something (i))
				continue;
			do_more ();
		}

	A few guidelines:

		* Use a space before an opening parenthesis when calling
		  functions, or indexing, like this:

			method (a);
			b [10];

		* Do not put a space after the opening parenthesis and the 
		  closing one, ie:

			good: method (a);	array [10];

			bad:  method ( a );	array[ 10 ];

		* Inside a code block, put the opening brace on the same line
	  	  as the statement:

			good:
				if (a) {
					code ();
					code ();
				}

			bad:
				if (a) 
				{
					code ();
					code ();
				}

		* Avoid using unecessary open/close braces, vertical space
		  is usually limited:

			good:
				if (a)
					code ();

			bad:
				if (a) {
					code ();
				}

		* When defining a method, use the C style for brace placement, 
		  that means, use a new line for the brace, like this:

			good:
				void Method ()
				{
				}

			bad:
				void Method () {
				}

		* Properties and indexers are an exception, keep the
		  brace on the same line as the property declaration.
		  Rationale: this makes it visually
		  simple to distinguish them.

			good:
				int Property {
					get {
						return value;
					}
				}

			bad:
				int Property 
				{
					get {
						return value;
					}
				}

		  Notice how the accessor "get" also keeps its brace on the same
		  line.

		  For very small properties, you can compress things:

			ok:
				int Property {
					get { return value; }
					set { x = value; }
				}

		* Use white space in expressions liberally, except in the presence
		  of parenthesis:

			good:

				if (a + 5 > method (blah () + 4))

			bad:
				if (a+5>method(blah()+4))

		* For any new files, please use a descriptive introduction, like
		  this:

			//
			// System.Comment.cs: Handles comments in System files.
			//
			// Author:
			//   Juan Perez (juan at address.com)
			//
			// (C) 2002 Address, Inc (http://www.address.com)
			//

		* If you are modyfing someone else's code, and your contribution
		  is significant, please add yourself to the Authors list.

		* Switch statements have the case at the same indentation as the
		  switch:

			switch (x) {
			case 'a':
				...
			case 'b':
				...
			}

		* Argument names should use the camel casing for
		  identifiers, like this:

		 	good:
				void Method (string myArgument)

			bad:
				void Method (string lpstrArgument)
				void Method (string my_string)

	Here are a couple of examples:

class X : Y {

	bool Method (int argument_1, int argument_2)
	{
		if (argument_1 == argument_2)
			throw new Exception (Locale.GetText ("They are equal!");

		if (argument_1 < argument_2) {
			if (argument_1 * 3 > 4)
				return true;
			else
				return false;
		}

		//
		// This sample helps keep your sanity while using 8-spaces for tabs
		// 
		VeryLongIdentifierWhichTakesManyArguments (
			Argument1, Argument2, Argument3,
			NestedCallHere (
				MoreNested));
	}

	bool MyProperty {
		get {
			return x;
		}

		set {
			x = value;
		}
	}

	void AnotherMethod () 
	{
		if ((a + 5) != 4) {
		}

		while (blah) {
			if (a)
				continue;
			b++;
		}
	}
}