3 CodingStyle - standards while programming for GNU LilyPond
7 Please use these standards while doing programming for GNU LilyPond
9 Functions and methods do not return errorcodes, but use assert for
14 A program should be light and agile, its subroutines
15 connected like a strings of pearls. The spirit and intent of
16 the program should be retained throughout. There should be
17 neither too little nor too much, neither needless loops nor
18 useless variables, neither lack of structure nor overwhelming
21 A program should follow the 'Law of Least
22 Astonishment'. What is this law? It is simply that the
23 program should always respond to the user in the way that
26 A program, no matter how complex, should act as a
27 single unit. The program should be directed by the logic
28 within rather than by outward appearances.
30 If the program fails in these requirements, it will be
31 in a state of disorder and confusion. The only way to correct
32 this is to rewrite the program.
34 -- Geoffrey James, "The Tao of Programming"
38 Definitions of classes that are only accessed via pointers
39 (*) or references (&) shall not be included as include files.
41 Include files in C++ always have the file name extension ".hh".
43 Implementation files in C++ always have the file name
46 Inline definition files always have the file name extension ".icc".
54 (add-hook 'c-mode-hook
55 '(lambda ()(setq c-basic-offset 4)))
58 (add-hook 'c++-mode-hook
59 '(lambda() (c-set-style "Stroustrup")
62 If you like using font-lock, you can also add this to your F<.emacs>:
64 (setq font-lock-maximum-decoration t)
65 (setq c++-font-lock-keywords-3
67 '("\\b\\([a-zA-Z_]+_\\)\\b" 1 font-lock-variable-name-face)
68 c++-font-lock-keywords-3))
70 =head2 CLASSES and TYPES:
73 AClass_name (for Abbreviation_class_name)
78 Type Class::member_type_
80 the C<type> is a Hungarian notation postfix for C<Type>. See below
85 The source is commented in the DOC++ style. Check out doc++ at
86 http://www.zib.de/Visual/software/doc++/index.html
89 C style comments for multiline comments.
90 They come before the thing to document.
97 Long class documentation.
110 short memo. long doco of member()
111 @param description of arguments
114 Rettype member(Argtype);
120 Unfortunately most of the code isn't really documented that good.
123 =head2 CLASSNAMES (2)
125 A lot of classes in GNU LilyPond start with 'P', this is to distinguish
126 certain parts of GNU LilyPond: the P stands for Printer, and the P-classes
127 are supposed to be more lowlevel than the others. Example:
129 Staff uses PStaff, PScore and PCol to do the typesetting of
130 symbols. Staff is the "brains" for PStaff
132 NB: in PCursor (which is part of the library) P stands for PointerCursor
139 ///check that *this satisfies its invariants, abort if not.
142 /// print *this (and substructures) to debugging log
146 protected member. Usually invoked by non-virtual XXXX()
150 /**add some data to *this.
151 Presence of these methods usually imply that it is not feasible to this
156 /// replace some data of *this
159 =head1 HUNGARIAN NOTATION NAMING CONVENTION
161 Proposed is a naming convention derived from the so-called I<Hungarian
166 The Hungarian Notation was conceived by or at least got its name from,
167 the hungarian programmer Charles Simonyi. It is a naming convention
168 with the aim to make code more readable (for fellow programmers), and
169 more accessible for programmers that are new to a project.
171 The essence of the Hungarian Notation is that every identifier has a
172 part which identifies its type (for functions this is the result
173 type). This is particularly useful in object oriented programming,
174 where a particular object implies a specific interface (a set of
175 member functions, perhaps some redefined operators), and for
176 accounting heap allocated memory pointers and links.
180 Another fun quote from Microsoft Secrets:
183 The Hungarian naming convention gives developers the ability
184 to read other people's code relatively easily, with a minmum
185 number of comments in the source code. Jon De Vann estimated
186 that only about 1 percent of all lines in the Excel product
187 code consist of comments, but the code is still very
188 understandable due to the use of Hungarian: "if you look at
189 our source code, you also notice very few comments. Hungarian
190 gives us the ability to go in and read code..."
193 Wow! If you use Hungarian you don't have to document your software!
194 Just think of the hours I have wasted documenting while this "silver bullet"
195 existed. I feel so stupid and ashamed!
203 more keystrokes (disk space!)
207 it looks silly C<get_slu_p()>
211 it looks like code from micro suckers
215 (which) might scare away some (otherwise good?)
216 progammers, or make you a paria in the free
225 not very useful if not used consistently
229 usefullness in I<very large>
230 (but how many classes is very large?)
243 learn about cut and paste / use emacs or vi
244 or lean to type using ten fingers
248 Use emacs dabbrev-expand, with dabbrev-case-fold-search set to nil.
252 use no, or pick less silly, abbrvs.
256 use non-ambiguous postfixes C<identifier_name_type_modifier[_modifier]>
260 Macros, C<enum>s and C<const>s are all uppercase,
261 with the parts of the names separated by underscores.
270 unsigned char. (The postfix _by is ambiguous)
299 Zero terminated c string
307 =head2 User defined types
314 Slur* slur_p = new Slur;
318 The following types modify the meaning of the prefix.
319 These are precede the prefixes:
333 const. Note that the proper order C<Type const> i.s.o. C<const Type>
337 A const pointer. This would be equivalent to C<_c_l>, but since any
338 "const" pointer has to be a link (you can't delete a const pointer),
343 temporary pointer to object (link)
347 pointer to newed object
359 Variable loop: an integer
363 Temporary variable: an unsigned integer
367 Variable test: a character
369 =item C<first_name_str>
371 Variable first_name: a String class object
373 =item C<last_name_ch_a>
375 Variable last_name: a C<char> array
379 Variable foo: an C<Int*> that you must delete
383 Variable bar: an C<Int*> that you must not delete
387 Generally default arguments are taboo, except for nil pointers.