3 CodingStyle - standards while programming for GNU LilyPond
7 We 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 string 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.
44 ".cc" Implementation files
45 ".icc" Inline definition files
46 ".tcc" non inline Template defs
51 (append '(("\\.make$" . makefile-mode)
53 ("\\.icc$" . c++-mode)
54 ("\\.tcc$" . c++-mode)
56 ("\\.pod$" . text-mode)
61 The class Class_name_abbreviation is coded in F<class-name-abbr.*>
69 (add-hook 'c++-mode-hook
70 '(lambda() (c-set-style "gnu")
74 If you like using font-lock, you can also add this to your F<.emacs>:
76 (setq font-lock-maximum-decoration t)
77 (setq c++-font-lock-keywords-3
79 c++-font-lock-keywords-3
80 '(("\\b\\([a-zA-Z_]+_\\)\\b" 1 font-lock-variable-name-face)
81 ("\\b\\([A-Z]+[a-z_]+\\)\\b" 1 font-lock-type-face))
84 =head2 CLASSES and TYPES:
87 AClass_name (for Abbreviation_class_name)
92 Type Class::member_type_
93 Type Class::member_type()
95 the C<type> is a Hungarian notation postfix for C<Type>. See below
99 Macros should be written completely in uppercase
101 The code should not be compilable if proper macro declarations are not
104 Don't laugh. It took us a whole evening/night to figure out one of
109 Broken code (hardwired dependencies, hardwired constants, slow
110 algorithms and obvious limitations) should be marked as such:
111 either with a verbose TODO, or with a short "ugh" comment.
115 The source is commented in the DOC++ style. Check out doc++ at
116 http://www.zib.de/Visual/software/doc++/index.html
119 C style comments for multiline comments.
120 They come before the thing to document.
127 Long class documentation.
130 TODO Fix boring_member()
142 short memo. long doco of member()
143 @param description of arguments
146 Rettype member(Argtype);
150 data_member_ = 121; // ugh
156 Unfortunately most of the code isn't really documented that good.
163 ///check that *this satisfies its invariants, abort if not.
166 /// print *this (and substructures) to debugging log
170 protected member. Usually invoked by non-virtual XXXX()
174 /**add some data to *this.
175 Presence of these methods usually imply that it is not feasible to this
180 /// replace some data of *this
185 Every class should have a default constructor.
187 Don't use non-default constructors if this can be avoided:
191 is less readable than
197 Foo f(Foo_convert::int_to_foo (1))
201 =head1 HUNGARIAN NOTATION NAMING CONVENTION
203 Proposed is a naming convention derived from the so-called I<Hungarian
208 The Hungarian Notation was conceived by or at least got its name from,
209 the hungarian programmer Charles Simonyi. It is a naming convention
210 with the aim to make code more readable (for fellow programmers), and
211 more accessible for programmers that are new to a project.
213 The essence of the Hungarian Notation is that every identifier has a
214 part which identifies its type (for functions this is the result
215 type). This is particularly useful in object oriented programming,
216 where a particular object implies a specific interface (a set of
217 member functions, perhaps some redefined operators), and for
218 accounting heap allocated memory pointers and links.
222 Another fun quote from Microsoft Secrets:
225 The Hungarian naming convention gives developers the ability
226 to read other people's code relatively easily, with a minmum
227 number of comments in the source code. Jon De Vann estimated
228 that only about 1 percent of all lines in the Excel product
229 code consist of comments, but the code is still very
230 understandable due to the use of Hungarian: "if you look at
231 our source code, you also notice very few comments. Hungarian
232 gives us the ability to go in and read code..."
234 Wow! If you use Hungarian you don't have to document your software!
235 Just think of the hours I have wasted documenting while this "silver bullet"
236 existed. I feel so stupid and ashamed! [Didn't MMM-Brooks say `There is
237 no silver bullet?' --HWN]
246 more keystrokes (disk space!)
250 it looks silly C<get_slu_p()>
254 it looks like code from micro suckers
258 (which) might scare away some (otherwise good?)
259 progammers, or make you a paria in the free
268 not very useful if not used consistently
272 usefullness in I<very large> (but how many classes is very large?)
285 learn about cut and paste / use emacs or vi
286 or lean to type using ten fingers
290 Use emacs dabbrev-expand, with dabbrev-case-fold-search set to nil.
294 use no, or pick less silly, abbrvs.
298 use non-ambiguous postfixes C<identifier_name_type_modifier[_modifier]>
302 Macros, C<enum>s and C<const>s are all uppercase,
303 with the parts of the names separated by underscores.
312 unsigned char. (The postfix _by is ambiguous)
341 Zero terminated c string
349 =head2 User defined types
356 Slur* slur_p = new Slur;
360 The following types modify the meaning of the prefix.
361 These are preceded by the prefixes:
375 const. Note that the proper order is C<Type const> i.s.o. C<const Type>
379 A const pointer. This would be equivalent to C<_c_l>, but since any
380 "const" pointer has to be a link (you can't delete a const pointer),
385 temporary pointer to object (link)
389 pointer to newed object
401 Variable loop: an integer
405 Temporary variable: an unsigned integer
409 Variable test: a character
411 =item C<first_name_str>
413 Variable first_name: a String class object
415 =item C<last_name_ch_a>
417 Variable last_name: a C<char> array
421 Variable foo: an C<Int*> that you must delete
425 Variable bar: an C<Int*> that you must not delete
429 Generally default arguments are taboo, except for nil pointers.
433 For some tasks, some scripts are supplied, notably creating patches, a
434 mirror of the website, generating the header to put over cc and hh
435 files, doing a release.
439 The following generic identifications are used:
446 Intervals are pictured lying on a horizontal numberline (Interval[-1]
447 is the minimum). The 2D plane has +x on the right, +y pointing up.