66 lines
2.2 KiB
Plaintext
66 lines
2.2 KiB
Plaintext
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Code conventions used internally by fftw3 (not in API):
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LEARN FROM THE MASTERS: read Ken Thompson's C compiler in Plan 9.
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Avoid learning from C++/Java programs.
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INDENTATION: K&R, 5 spaces/tab. In case of doubt, indent -kr -i5.
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NAMES: keep them short. Shorter than you think. The Bible was written
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without vowels. Don't outsmart the Bible.
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Common names:
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R : real type, aka fftw_real
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E : real type for local variables (possibly extra precision)
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C : complex type
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sz : size
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vecsz : vector size
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is, os : input/output stride
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ri, ii : real/imag input (complex data)
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ro, io : real/imag output (complex data)
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I, O : real input/output (real data)
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A : assert
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CK : check
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S : solver, defined internally to each solver file
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P : plan, defined internally to each solver file
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k : codelet
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X(...) : used for mangling of external names (see below)
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K(...) : floating-point constant, in E precision
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If a name is used often and must have the form fftw_foo to avoid
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namespace pollution, #define FOO fftw_foo and use the short name.
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Leave that hungarian crap to MS. foo_t counts as hungarian: use
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foo instead. foo is lowercase so that it does not look like a DOS
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program. Exception: typedef struct foo_s {...} foo; instead of
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typedef struct foo {...} foo; for C++ compatibility.
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NAME MANGLING: use X(foo) for external names instead of fftw_foo.
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X(foo) expands to fftwf_foo or fftw_foo, depending on the
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precision. (Unfortunately, this is a ugly form of hungarian
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notation. Grrr...) Names that are not exported do not need to be
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mangled.
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REPEATED CODE: favor a table. E.g., do not write
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foo("xxx", 1);
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foo("yyy", 2);
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foo("zzz", -1);
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Instead write
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struct { const char *nam, int arg } footab[] = {
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{ "xxx", 1 },
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{ "yyy", 2 },
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{ "zzz", -1 }
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};
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and loop over footab. Rationale: it saves code space.
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Similarly, replace a switch statement with a table whenever
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possible.
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C++: The code should compile as a C++ program. Run the code through
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gcc -xc++ . The extra C++ restrictions are unnecessary, of
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course, but this will save us from a flood of complaints when
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we release the code.
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