Technical data

Working with the Target Language

2-18

Conditional Inclusion

The conditional inclusion directives are

%if constant-expression

%else

%elseif constant-expression

%endif

and

%switch constant-expression

%case constant-expression

%break

%default

%endswitch

%if

The constant-expression must evaluate to an integral expression. It controls

the inclusion of all the following lines until it encounters a

%else, %elseif, or

%endif directive. If the constant-expression evaluates to 0, the lines

following the directive are not included. If the

constant-expression evaluates

to any other integral value, the lines following the

%if directive are included

up until the

%endif, %elseif, or %else directives.

When the Compiler encounters an

%elseif directive, and no prior %if or

%elseif directive has evaluated to nonzero, the Compiler evaluates the

expression. If the value is 0, the lines following the

%elseif directive are not

included. If the value is nonzero, the lines following the

%elseif directive are

included up until the subsequent

%else, %elseif, or %endif directive.

The

%else directive begins the inclusion of source text if all of the previous

%elseif statements or the original %if statement evaluates to 0; otherwise, it

prevents the inclusion of subsequent lines up to and including the following

%endif.

The

constant-expression can contain any expression specified in the “Target

Language Expressions” section.