#ifndef

Conditional reading of code.

Macros are textual replacements which are made in the orchestra as it is being read. The orchestra macro system in Csound is a very simple one, and uses the characters # and $ to define and call macros. This can save typing, and can lead to a coherent structure and consistent style. This is similar to, but independent of, the macro system in the score language.

If the specified macro is not defined then #ifndef can incorporate text into an orchestra upto the next #end.

Syntax

#ifndef NAME
....
#else
....
#end

Performance

Note that the #ifndef can be nested, like in the C preprocessor language.

Examples

Here is a simple example of the conditional.

Simple example of the #ifndef form.

#define final ##
    instr 1
#ifndef final
    print "calling oscil"
#end
    a1   oscil 32000,440,1
    out  a1
    endin

See also

Orchestra Macros

Credits

Author: John ffitch
University of Bath/Codemist Ltd.
Bath, UK
April 2005

New in Csound5 (and 4.23f13)