Technical data

2
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.