Given a previously declared var_model, the var_expectation_model statement is
used to declare a way of forming expectations with this VAR (possibly using a
finite or infinite discounted sum). The var_expectation operator now takes a
single argument, the name of the var_expectation_model.
For the moment, this only works when the var_model is using equations
explicitly declared in the model block.
We can therefore manipulate objects by value rather than by pointers, which
saves a lot of memory manipulations (and avoid potential segfaults and memory
leaks).
Note that there is no default action ("$$ = $1") when using the variant type,
so we add them explicitly.
Those were treated as comments.
Incidentally, fix a similar issue in the Dynare parser (which is much less
problematic, since double quotes are not used in the Dynare language).
ClosesDynareTeam/dynare#1621
Houtan Bastani
Sébastien Villemot
Stéphane Adjemian(Charybdis)