NB: the “overwrite” option only works for the same type of “learnt_in” value,
i.e. an integer-valued “learnt_in” cannot replace a date-valued “learnt_in” and
vice versa.

Closes: #104

This is cleaner than using exit() or assert() for that purpose.

For consistency with other such classes, since it represents the homotopy_setup
block.

In particular, use a std::variant to store the values of options. This ensures
that a given option name can have only one value (previously, for a given
option name, it was possible to store several values as long as they were of
different types).

As a consequence, add many [[maybe_unused]] attributes for legitimate
cases (mainly in virtual functions).

In particular, use this feature in many loops which feature a special treatment
for the first iteration, using a boolean variable (replacing iterator
manipulation). By the way, also use std::exchange() to simultaneously test the
value of this variable and update it.

Incidentally, forbid exogenous deterministic variables in “endval” blocks.

For use with perfect_foresight_with_expectation_errors_setup.

Closes: #82

The Julia code now uses the JSON output for retrieving the information that
previously was in the driver file.

MichelJuillard authored 4 years ago and Sébastien Villemot committed 4 years ago

(cherry picked from commit c8575e11)

Ref. dynare#1173

Allows for the inclusion/exclusion of a set of equations, specified either on the command line or in a text file.

If the equation has a single endogenous variable on the LHS, then the equation is moved. If not, if the equation has an `endogenous` tag then that variable is removed along with this equation. If not, then an error is thrown.

As a command line argument, `exclude_eqs` can take the form (same syntax for `include_eqs`):
* `exclude_eqs=eq1 to remove all equations declared as `[name=eq1]`
* `exclude_eqs=[eq 1, eq 2]` to remove all equations declared as `[name=eq 1]` or `[name=eq 2]`
* `exclude_eqs=[tagname=X]` to remove all equations declared as `[tagname=X]`
* `exclude_eqs=[tagname=(X, Y)]` to remove all equations declared as `[tagname=X]` or `[tagname=Y]`

When declared in a file, the file should be of the form:
```
eq 1
eq 2
```
to remove all equations declared as `[name=eq 1]` or `[name=eq 2]`.

It should be of the form:
```
tagname=
X
Y
```
to remove all equations declared as `[tagname=X]` or `[tagname=Y]`.

These functions should have been deleted in
946d105c.

Basically revert the change made in 30c205f4,
since it lead to preprocessor crashes (via C++ exceptions).

Use ReplaceShorterLiterals option to enforce replacement of all strings.

https://clang.llvm.org/extra/clang-tidy/checks/modernize-raw-string-literal.html

This is more elegant, and makes it easier to distinguish them from integer
options.