A backquote expression can be dynamically compiled using the compile special form, which is described in Section 2.
In particular, if the dynamic statement or compound statement contains a return statement, the type of the return value does not affect the type of the backquote expression.
A vspec inside a backquote expression can thus be used like a traditional C variable, both as an lvalue and an rvalue.
The backquote operator allows a programmer to create code at run time.
can only be applied inside a backquote expression, and its operand must be a cspec or vspec.
Applying @ inside a backquote expression to a function (which must return a cspec or a vspec) causes the function to be called at environment binding time.
Statements (and compound statements) are considered to have type void; an object of type void cspec inside a backquote expression cannot be used inside an expression, but can be composed as an expression statement:
may only appear inside a backquote expression, and it may not be unquoted.