# Todo List

- create a testsuite

## Features

- add "elsif" and "switch/case" in macro-language
- add option for number of draw in Metropolis subsamples [parser + Matlab code]
- add option for algorithm to solve generalized Sylverster equation [parser + Matlab code]
- add new function diff(), sum loops and prod loops in modeling language. Should be unrolled. [parser]

## Error checking

- add a check for number of equations and endogenous in the case of Ramsey policy
improve error message when dealing with Expr

`Node::Eval``Exception (in particular for reporting in Model``Tree::evaluateJacobian)`- add warning for missing variable in current period. This is permissible in some cases, Michel should write a note about it [parser]
- improve error and warning handling in parser. Find a way that users see Warnings even if scrolling by [parser]

### Checks concerning the structure of the mod file

- allow a single histval, endval, initval block
- check that a given parameter is never declared two times
- check that observation trends is used after a varobs
- add a warning if homotopy_setup block comes after steady

### Checks concerning the types of variables allowed in expressions

- varobs must be declared endogenous
- shocks must be exogenous
- objective_planner must be endogenous without leads/lags

## Optimizations / Enhancements

optimize expression sharing (for example use the fact that A+(B+C) = (A+B)+C); this would also enhance the pre-computing of numerical constants (for the moment, the algorithm can't reduce

`1+(x+1)`)if there is a series of operators with the same precedence, we can collect the constant and reduce them

`1+(x+2}=(1+2)+x=3+x`but it is possible to factorize more complicated expressions:

`2*x+3*x=(2+3)*x=5*x`. The two simplifications aren't identical but strongly related. -- MichelJuillard 2007-05-08 19:53:46

rewrite outputting system (by using a subclass of ostream containing the output type, and by overloading << operator)

- improve internal representation of estimated_params* statements