3 CodingStyle - standards while programming for GNU LilyPond
7 We use these standards while doing programming for GNU LilyPond. If
8 you do some hacking, we appreciate it if you would follow this rules,
9 but if you don't, we still like you.
11 Functions and methods do not return errorcodes, but use assert for
16 A program should be light and agile, its subroutines
17 connected like a string of pearls. The spirit and intent of
18 the program should be retained throughout. There should be
19 neither too little nor too much, neither needless loops nor
20 useless variables, neither lack of structure nor overwhelming
23 A program should follow the 'Law of Least
24 Astonishment'. What is this law? It is simply that the
25 program should always respond to the user in the way that
28 A program, no matter how complex, should act as a
29 single unit. The program should be directed by the logic
30 within rather than by outward appearances.
32 If the program fails in these requirements, it will be
33 in a state of disorder and confusion. The only way to correct
34 this is to rewrite the program.
36 -- Geoffrey James, "The Tao of Programming"
40 Definitions of classes that are only accessed via pointers
41 (*) or references (&) shall not be included as include files.
46 ".cc" Implementation files
47 ".icc" Inline definition files
48 ".tcc" non inline Template defs
53 (append '(("\\.make$" . makefile-mode)
55 ("\\.icc$" . c++-mode)
56 ("\\.tcc$" . c++-mode)
58 ("\\.pod$" . text-mode)
63 The class Class_name_abbreviation is coded in F<class-name-abbr.*>
71 (add-hook 'c++-mode-hook
72 '(lambda() (c-set-style "gnu")
76 If you like using font-lock, you can also add this to your F<.emacs>:
78 (setq font-lock-maximum-decoration t)
79 (setq c++-font-lock-keywords-3
81 c++-font-lock-keywords-3
82 '(("\\b\\([a-zA-Z_]+_\\)\\b" 1 font-lock-variable-name-face)
83 ("\\b\\([A-Z]+[a-z_]+\\)\\b" 1 font-lock-type-face))
86 =head2 CLASSES and TYPES:
89 AClass_name (for Abbreviation_class_name)
94 Type Class::member_type_
95 Type Class::member_type()
97 the C<type> is a Hungarian notation postfix for C<Type>. See below
101 Macros should be written completely in uppercase
103 The code should not be compilable if proper macro declarations are not
106 Don't laugh. It took us a whole evening/night to figure out one of
111 Broken code (hardwired dependencies, hardwired constants, slow
112 algorithms and obvious limitations) should be marked as such:
113 either with a verbose TODO, or with a short "ugh" comment.
117 The source is commented in the DOC++ style. Check out doc++ at
118 http://www.zib.de/Visual/software/doc++/index.html
121 C style comments for multiline comments.
122 They come before the thing to document.
129 Long class documentation.
132 TODO Fix boring_member()
144 short memo. long doco of member()
145 @param description of arguments
148 Rettype member(Argtype);
152 data_member_ = 121; // ugh
158 Unfortunately most of the code isn't really documented that good.
165 ///check that *this satisfies its invariants, abort if not.
168 /// print *this (and substructures) to debugging log
172 protected member. Usually invoked by non-virtual XXXX()
176 /**add some data to *this.
177 Presence of these methods usually imply that it is not feasible to this
182 /// replace some data of *this
187 Every class should have a default constructor.
189 Don't use non-default constructors if this can be avoided:
193 is less readable than
199 Foo f(Foo_convert::int_to_foo (1))
203 =head1 HUNGARIAN NOTATION NAMING CONVENTION
205 Proposed is a naming convention derived from the so-called I<Hungarian
210 The Hungarian Notation was conceived by or at least got its name from,
211 the hungarian programmer Charles Simonyi. It is a naming convention
212 with the aim to make code more readable (for fellow programmers), and
213 more accessible for programmers that are new to a project.
215 The essence of the Hungarian Notation is that every identifier has a
216 part which identifies its type (for functions this is the result
217 type). This is particularly useful in object oriented programming,
218 where a particular object implies a specific interface (a set of
219 member functions, perhaps some redefined operators), and for
220 accounting heap allocated memory pointers and links.
224 Another fun quote from Microsoft Secrets:
227 The Hungarian naming convention gives developers the ability
228 to read other people's code relatively easily, with a minmum
229 number of comments in the source code. Jon De Vann estimated
230 that only about 1 percent of all lines in the Excel product
231 code consist of comments, but the code is still very
232 understandable due to the use of Hungarian: "if you look at
233 our source code, you also notice very few comments. Hungarian
234 gives us the ability to go in and read code..."
236 Wow! If you use Hungarian you don't have to document your software!
237 Just think of the hours I have wasted documenting while this "silver bullet"
238 existed. I feel so stupid and ashamed! [Didn't MMM-Brooks say `There is
239 no silver bullet?' --HWN]
248 more keystrokes (disk space!)
252 it looks silly C<get_slu_p()>
256 it looks like code from micro suckers
260 (which) might scare away some (otherwise good?)
261 progammers, or make you a paria in the free
270 not very useful if not used consistently
274 usefullness in I<very large> (but how many classes is very large?)
287 learn about cut and paste / use emacs or vi
288 or lean to type using ten fingers
292 Use emacs dabbrev-expand, with dabbrev-case-fold-search set to nil.
296 use no, or pick less silly, abbrvs.
300 use non-ambiguous postfixes C<identifier_name_type_modifier[_modifier]>
304 There is no need for Hungarian if the scope of the variable is small,
305 ie. local variables, arguments in function definitions (not
310 Macros, C<enum>s and C<const>s are all uppercase,
311 with the parts of the names separated by underscores.
320 unsigned char. (The postfix _by is ambiguous)
349 Zero terminated c string
357 =head2 User defined types
364 Slur* slur_p = new Slur;
368 The following types modify the meaning of the prefix.
369 These are preceded by the prefixes:
383 const. Note that the proper order is C<Type const> i.s.o. C<const Type>
387 A const pointer. This would be equivalent to C<_c_l>, but since any
388 "const" pointer has to be a link (you can't delete a const pointer),
393 temporary pointer to object (link)
397 pointer to newed object
409 Adjectives such as global and static should be spelled out in full.
410 They come before the noun that they refer to, just as in normal english.
412 foo_global_i: a global variable of type int commonly called "foo".
414 static class members do not need the static_ prefix in the name (the
415 Class::var notation usually makes it clear that it is static)
419 Variable loop: an integer
423 Temporary variable: an unsigned integer
427 Variable test: a character
429 =item C<first_name_str>
431 Variable first_name: a String class object
433 =item C<last_name_ch_a>
435 Variable last_name: a C<char> array
439 Variable foo: an C<Int*> that you must delete
443 Variable bar: an C<Int*> that you must not delete
447 Generally default arguments are taboo, except for nil pointers.
449 The naming convention can be quite conveniently memorised, by
450 expressing the type in english, and abbreviating it
452 static Array<int*> foo
454 C<foo> can be described as "the static int-pointer user-array", so you get
463 For some tasks, some scripts are supplied, notably creating patches, a
464 mirror of the website, generating the header to put over cc and hh
465 files, doing a release.
469 The following generic identifications are used:
476 Intervals are pictured lying on a horizontal numberline (Interval[-1]
477 is the minimum). The 2D plane has +x on the right, +y pointing up.