2.3 Naming and Argument Conventions

Throughout CLX, a number of conventions for naming and syntax of the CLX functions have been followed. These conventions are intended to make the syntax of the functions more predictable.

The major naming conventions are as follows:

• To better differentiate the CLX symbols from other symbols, they have all been placed in the package XLIB. External symbols have been explicitly exported.
• The display argument, where used, is always first in the argument list.
• All server resource objects, where used, occur at the beginning of the argument list, immediately after the display variable.
• When a graphics context (gcontext) is present together with another type of server resource (most commonly, a drawable), the graphics context occurs in the argument list after the other server resource. Drawables out rank all other server resources.
• Source arguments always precede the destination arguments in the argument list.
• The x argument always precedes the y argument in the argument list.
• The width argument always precedes the height argument in the argument list.
• Where the x, y, width and height arguments are used together, the x and y arguments always precede the width and height arguments.
• Where a mask is accompanied with a structure, the mask always precedes the structure in the argument list.