Chapter 11 Writing Macro Control Statements206 Purpose of This Chapter11.1 Purpose of This ChapterMacros consist of two parts: macro definitions and macro calls. A macro that has been defined can becoded as a macro call in any source statement after that.When a macro without parameters is called, it becomes a simple text substitution. When a macro withparameters is called, part of the text to be substituted will be modified by the strings specified as theparameters.This chapter explains how define and call macros. It also describes the directives used for macros.Common coding rulesThe characters that can be used for macro names, dummy parameters, parameters, and identifiers areupper and lower case letters, digits, and underscores (_). The first character must not be a digit.Symbols used in expressions must have been previously defined.The following directives cannot be coded within macro blocks.#include directivemacro definitionsRefer to section 11.2, "Macro Definitions", regarding macro definitions and blocks.The rept and irp directives and macro calls can be coded within macro blocks. Up to 20 nesting levelsare allowed.A dummy parameter appearing in a string or character constant inside the macro is not expanded.Document conventionsSymbols used in this chapter have the following meanings.[ ] Contents of brackets [ ] may be omitted.( ) Contents of parentheses ( ) may be repeated.
