The RWP*Load Simulator includes parsing and execution just like any ordinary programming language, but these two phases are handled implicitly. When a procedure or a function is declared, the statements that it contains, which includes both actually executable code (such as assignments) and declarations of simple scalars and SQL, are compiled and saved internally (in memory) for later execution. At the top level, statements can also be executed directly during parsing of your input files. If you e.g. provide this as input to rwloadsim:
integer a;
a := 10;
if a<10 then
printline "a is less than ten";
end if;
the two first statements, the declaration of the integer variable a and the assignment to it are directly executed as they are parsed. The if/then/end code, however, is compiled into an anonymous procedure on the fly, and it is subsequently executed. Internally this snippet includes both compilation and execution, while the user sees it as one.
As there is no complete compilation of your entire input before execution starts, your input may be partly executed even if there are syntax errors. As an example, the following input to rwloadsim
integer aa := 10;
printline "aa has the value", aa;
if aa<10 thenn
printline "aa is smaller than ten";
end if;
will execute the first two lines showing the output from the first printline and then subsequently give you a syntax error due to the misspelled keyword then.
Using the -e option prevents rwloadsim from executing any declared function, procedure or SQL, so this can be used to show syntax errors.